CN109716795B - Networked microphone device, method therefor, and media playback system - Google Patents

Abstract

Example techniques may involve performing aspects of spectral calibration using applied spatial calibration. Example implementations may include: data representing spatial filters corresponding to respective playback configurations is received. The implementation may also involve: causing the audio driver to output calibration audio divided into a repeating set of frames including a respective frame for each playback configuration. Causing the audio driver to output the calibration audio may involve: the audio stage is caused to apply a spatial filter corresponding to the respective playback configuration during each frame. The implementation may further include: data representing spectral filters corresponding to respective playback configurations is received, the spectral filters based on the calibrated audio output by the audio driver. When playing back audio content in a given playback configuration, the audio stage may apply a particular spectral filter corresponding to that configuration.

Description

Networked microphone device, method therefor, and media playback system

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to US Patent Application Serial No. 15/211,835, filed July 15, 2016, and US Patent Application No. 15/211,822, filed July 15, 2016, the entire contents of which are incorporated by reference in their entirety in the text. Additional incorporation by reference is made throughout the disclosure.

technical field

The present disclosure relates to consumer products, and more particularly, to methods, systems, products, features, services, and other elements for media playback or aspects thereof.

Background technique

Until 2003, SONOS Corporation filed one of its first patent applications entitled "Method for Synchronizing Audio Playbackbetween Multiple Networked Devices", and in 2005 began offering a media playback system for sale for access and listening in loud settings Digital audio options are limited. Sonos wireless hi-fi systems enable people to experience music from many sources via one or more networked playback devices. Through a software-controlled application installed on a smartphone, tablet or computer, a person can play what he or she wants in any room with a networked playback device. Additionally, using the controller, for example, playback devices can be used to stream different songs to each room, rooms can be grouped together for synchronized playback, or the same song can be listened to in all rooms synchronously.

Given the growing interest in digital media, there is still a need to develop consumer-accessible technologies to further enhance the listening experience.

Description of drawings

The features, aspects, and advantages of the disclosed technology may be better understood upon consideration of the following description, appended claims, and accompanying drawings, in which:

1 illustrates an example media playback system configuration in which certain embodiments may be practiced;

Figure 2 shows a functional block diagram of an example playback device;

Figure 3 shows a functional block diagram of an example control device;

Figure 4 shows an example controller interface;

Figure 5 shows an example control device;

6 illustrates a smartphone displaying an example control interface, according to an example implementation;

7 illustrates example movement through an example environment in which an example media playback system is located;

Figure 8 shows an example chirp with increasing frequency over time;

Figure 9 shows an example Brownian noise spectrum;

Figures 10A and 10B illustrate transition frequency ranges for example hybrid calibration sounds;

Figure 11 shows frames illustrating iterations of an example periodic calibration sound;

12 shows a series of frames illustrating iterations of an example periodic calibration sound;

FIG. 13 shows an example flow diagram for facilitating spatial calibration;

Figure 14 shows an example frame illustrating calibration audio divided into frames and time slots;

15 illustrates a smartphone displaying an example control interface, according to an example implementation;

16 illustrates a smartphone displaying an example control interface according to an example implementation;

17 illustrates a smartphone displaying an example control interface, according to an example implementation;

18 illustrates a smartphone displaying an example control interface according to an example implementation;

Figure 19 shows an example flow diagram for facilitating spatial calibration using applied spatial calibration;

FIG. 20 shows an example flow diagram for facilitating spatial calibration using the applied spatial calibration; and

21 illustrates a smartphone displaying an example control interface, according to an example implementation.

The drawings are for purposes of illustrating example embodiments, it being understood, however, that the invention is not limited to the arrangements and instrumentalities shown in the drawings.

Detailed ways

I. Overview

Embodiments described herein relate, inter alia, to techniques that facilitate calibration of media playback systems. Some calibration procedures contemplated herein involve recording devices (eg, networked microphone devices (NMDs)) detecting sound waves (eg, one or more calibration sounds) emitted by one or more playback devices of a media playback system. A processing device such as a recording device, a playback device, or another device communicatively coupled to the media playback system may analyze the detected sound waves to determine one or more calibrations for one or more playback devices of the media playback system. When applied, such calibration can configure one or more playback devices to a given listening area (ie, an environment in which the one or more playback devices are positioned while sound waves are emitted).

In some embodiments contemplated herein, the processing device may determine a first type of calibration. For example, the processing device may determine a spatial calibration that spatially configures one or more playback devices to a given listening area. Such calibration may configure one or more playback devices to one or more specific locations within the environment (eg, one or more preferred listening locations, such as favorite seating locations), possibly by targeting those specific locations Adjust time delay and/or loudness to configure. Spatial calibration may include one or more filters including delay and/or phase adjustments, gain adjustments, and/or any other adjustments to correct one or more playback devices relative to one or more specific positions within the environment space placement.

As described above, during the calibration process, one or more playback devices of the media playback system may output calibration sounds. Some example media playback systems may include multiple audio drivers that may be divided among one or more playback devices of the media playback system in various arrangements. For example, an example media playback system may include a sound bar-type playback device having multiple audio drivers (eg, nine audio drivers). Another playback device may include multiple different types of audio drivers (eg, tweeters and woofers that may have different sizes). Other example playback devices may include a single audio driver (eg, a single full-range woofer in a playback device, or a large low-frequency woofer in a subwoofer-type device).

In operation, multiple audio drivers of a media playback system may form multiple "sound axes." Each such "sound axis" may correspond to a corresponding input channel of audio content. In some implementations, two or more audio drivers can be arranged to form an acoustic axis. For example, a sound bar-type device may include nine audio drivers that form multiple sound axes (eg, a front surround channel, a left surround channel, and a right surround channel). Any audio driver can contribute to any number of sound axes. For example, the left axis of a surround sound system may be formed by the contributions of all nine audio drivers in an example soundbar-type device. Alternatively, the shaft may be formed by a single audio driver.

The example media playback systems described herein may employ various playback configurations representing respective sets of sound axes. Example playback configurations may include corresponding configurations based on the number of input channels (eg, mono, stereo, surround, or any combination of the above with a subwoofer). Other example playback configurations can be based on content type. For example, a first set of axes may be formed by an audio driver of a media playback system when playing music, and a second set of axes may be formed by an audio driver when playing audio paired with video (eg, television audio). Other playback confirmations may be caused by various groupings of playback devices within the media playback system. Many examples are possible.

During some example calibration processes, multiple audio drivers of a media playback system may form multiple acoustic axes, such that each acoustic axis outputs sound during the calibration process. For example, calibration audio from multiple audio drivers can be divided into constituent frames. Each frame can in turn be divided into time slots. During each time slot of a given frame, a corresponding sound axis can be formed by outputting audio. In this way, the NMD recording the audio output of the audio driver can obtain samples from each acoustic axis. Frames can be repeated to produce multiple samples for each acoustic axis when recorded by the NMD.

Another type of calibration that can be produced by the example calibration process described herein is spectral calibration. Spectral calibration may spectrally configure one or more playback devices of a media playback system across a given listening area. Such calibration can often help compensate for the acoustic properties of the environment, rather than pointing relatively more towards a specific listening position as spatial calibration does. Spectral calibration may include one or more filters that adjust the frequency response of the playback device. In operation, one of the two or more calibrations may be applied to the playback of one or more playback devices, possibly for different use cases. Example use cases may include music playback or surround sound (ie home theater), among others.

In some example calibration procedures contemplated herein, the media playback system may perform a first calibration to determine a spatial calibration for one or more playback devices of the media playback system. The media playback system may then apply the spatial calibration while the playback device is emitting audio during the second calibration to determine the spectral calibration. Such a calibration process can result in a calibration that includes both spatial and spectral corrections.

Example techniques may involve various aspects of performing spatial calibration. A first implementation may include detecting a trigger condition that initiates calibration of a media playback system including a plurality of audio drivers forming a plurality of sound axes, each sound axis corresponding to a respective channel of the multi-channel audio content. The first implementation may also include causing a plurality of audio drivers to emit calibration audio that is divided into frames, the plurality of sound axes emitting calibration audio during respective time slots of each framed frame. The first implementation may also include recording the emitted calibration audio via the microphone. The first implementation may include: causing a delay for each of the plurality of acoustic axes to be determined, the determined delay for each acoustic axis being based on a time slot of the recorded calibration audio corresponding to the acoustic axis; and causing the calibration of the plurality of acoustic axes sound axis. Calibrating the plurality of sound axes may involve causing the audio output of the plurality of sound axes to be delayed according to the determined respective delays.

A second implementation may include receiving data representing one or more spatial filters corresponding to respective playback configurations. Each playback configuration may represent a particular set of sound axes formed via one or more audio drivers, and each sound axis may correspond to a corresponding channel of audio content. The second implementation may also involve causing one or more audio drivers to output calibration audio that is divided into repeated sets of frames, the set of frames including respective frames configured for each playback. Causing the one or more audio drivers to output calibration audio may involve causing the audio stage to apply a spatial filter corresponding to the respective playback configuration during each frame. The second implementation may also include receiving data representing one or more spectral filters corresponding to respective playback configurations, the one or more spectral filters based on calibration audio output by the one or more audio drivers. When playing back audio content in a given playback configuration, the audio stage may apply specific spectral filters corresponding to the given playback configuration.

A third implementation may include detecting a trigger condition that initiates calibration of the media playback system for multiple playback configurations. Each playback configuration represents a particular set of sound axes formed via multiple audio drivers of the media playback system, and each sound axis may correspond to a corresponding channel of audio content. A third implementation may also involve causing the plurality of audio drivers to output calibration audio that is divided into repeated sets of frames, the set of frames including respective frames configured for each playback. Causing the plurality of audio drivers to output calibration audio may involve causing a corresponding set of spatial filters to be applied to the plurality of audio drivers during each frame of the set of frames, each set of spatial filters including a corresponding spatial for each acoustic axis filter. The third implementation may also involve recording, via the microphones, calibration audio output by the plurality of audio drivers, and causing the processing device to determine, based on the recorded calibration audio, respective sets of spectral filters for the plurality of playback configurations, each spectral filter The set includes a corresponding spectral filter for each acoustic axis.

Each of these example implementations can be implemented as a method, an apparatus configured to perform the implementations, a system configured to perform the implemented apparatus, or a non-transitory computer containing instructions executable by one or more processors to perform the implemented implementations readable media, and other examples. Those of ordinary skill in the art will appreciate that the present disclosure includes many other embodiments, including combinations of the example features described herein. Furthermore, any example operations described as being performed by a given device to illustrate the techniques may be performed by any suitable device, including the devices described herein. Furthermore, any device can cause another device to perform any of the operations described herein.

While some of the examples described herein may relate to functions performed by a given actor, such as a "user" and/or other entities, it should be understood that this description is for illustration purposes only. A claim should not be construed as requiring an action by any such example actor unless the language of the claim itself clearly requires it.

II. Example Operating Environment

1 illustrates an example configuration of a media playback system 100 in which one or more embodiments disclosed herein may be practiced or implemented. The illustrated media playback system 100 is associated with an example home environment having several rooms and spaces, such as a master bedroom, office, dining room, and living room. As shown in the example of FIG. 1 , media playback system 100 includes playback device 102 to playback device 124 , control devices 126 and 128 , and wired or wireless network router 130 .

Further discussion regarding the different components of the example media playback system 100 and how the different components may interact to provide a user with a media experience can be found in the following sections. Although the discussion herein may generally relate to the example media playback system 100, the techniques described herein are not limited to application within a home environment or the like as shown in FIG. 1 . For example, the techniques described herein may be useful in the following environments where multi-zone audio may be desired: such as commercial environments such as restaurants, malls or airports, vehicles such as sport utility vehicles (SUVs), buses or cars, ships or boats , aircraft, etc.

a. Example playback device

FIG. 2 illustrates a functional block diagram of an example playback device 200 that may be configured as one or more of playback devices 102 through 124 of media playback system 100 of FIG. 1 . Playback device 200 may include: processor 202 , software component 204 , memory 206 , audio processing component 208 , audio amplifier 210 , speakers 212 , network interface 214 including wireless interface 216 and wired interface 218 . In one case, playback device 200 may not include speakers 212, but may include a speaker interface for connecting playback device 200 to external speakers. In another case, playback device 200 may include neither speaker 212 nor audio amplifier 210, but may include an audio interface for connecting playback device 200 to an external audio amplifier or audiovisual receiver.

In one example, processor 202 may be a clock-driven computing component configured to process input data according to instructions stored in memory 206 . Memory 206 may be a tangible computer-readable medium configured to store instructions executable by processor 202 . For example, memory 206 may be a data storage device that may be loaded with one or more of software components 204 executable by processor 202 to implement certain functions. In one example, a function may involve playback device 200 retrieving audio data from an audio source or another playback device. In another example, the function may involve playback device 200 sending audio data to another device or playback device on the network. In yet another example, functionality may involve pairing of playback device 200 with one or more playback devices to create a multi-channel audio environment.

Certain functions may involve playback device 200 synchronizing playback of audio content with one or more other playback devices. During synchronized playback, the listener will preferably not perceive a difference in time delay between the playback of the audio content by playback device 200 and the playback of the audio content by one or more other playback devices. US Patent No. 8,234,395, entitled "System and method for synchronizing operations among a plurality of independently clocked digital data processing devices," which is hereby incorporated by reference, provides in more detail some of the methods for audio playback synchronization between playback devices Example.

The memory 206 may also be configured to store data associated with the playback device 200, such as one or more zones and/or groups of zones of which the playback device 200 is a part, audio sources accessible by the playback device 200, or A playback queue associated with device 200 (or some other playback device). This data may be stored as one or more state variables that are periodically updated and used to describe the state of playback device 200 . The memory 206 may also include data that is associated with the state of other devices of the media system and is shared among the devices from time to time so that one or more of the devices has the most recent data associated with the system. Other implementations are also possible.

Audio processing components 208 may include one or more digital-to-analog converters (DACs), audio preprocessing components, audio enhancement components, or digital signal processors (DSPs), among others. In one embodiment, one or more of the audio processing components 208 may be subcomponents of the processor 202 . In one example, audio processing component 208 can process and/or intentionally alter audio content to generate audio signals. The resulting audio signal may then be provided to audio amplifier 210 for amplification and playback through speakers 212 . In particular, audio amplifier 210 may include a device configured to amplify an audio signal to a level for driving one or more of speakers 212 . Speakers 212 may include individual transducers (eg, "drivers"), or a complete speaker system including an enclosure with one or more drivers. Particular drivers for speakers 212 may include, for example, subwoofers (eg, for low frequencies), mid-range drivers (eg, for mid frequencies), and/or tweeters (eg, for high frequencies). In some cases, each transducer in one or more speakers 212 may be driven by a separate corresponding audio amplifier of audio amplifier 210 . In addition to generating analog signals for playback by playback device 200, audio processing component 208 may be configured to process audio content to be sent to one or more other playback devices for playback.

Audio content to be processed and/or played back by playback device 200 may be received from an external source, eg, via an audio line-in connection (eg, auto-detection of a 3.5mm audio line-in connection) or network interface 214 .

Network interface 214 may be configured to facilitate data flow between playback device 200 and one or more other devices on the data network. Likewise, playback device 200 may be configured to receive audio content over a data network from one or more other playback devices in communication with playback device 200, network devices within a local area network, or audio content sources over a wide area network such as the Internet. In one example, audio content and other signals sent and received by playback device 200 may be sent in the form of digital packet data containing an Internet Protocol (IP)-based source address and an IP-based destination address. In such a case, the network interface 214 may be configured to parse the digital packet data so that the playback device 200 properly receives and processes the data destined for the playback device 200 .

As shown, the network interface 214 may include a wireless interface 216 and a wired interface 218 . The wireless interface 216 may provide network interface functionality for the playback device 200 to communicate with other devices in accordance with a communication protocol (eg, any wireless standard, including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communication standards, etc.) (eg, other playback devices, speakers, receivers, network devices, control devices within the data network associated with playback device 200) communicate wirelessly. Wired interface 218 may provide playback device 200 with network interface functionality to communicate with other devices over a wired connection according to a communication protocol (eg, IEEE 802.3). Although the network interface 214 shown in FIG. 2 includes both the wireless interface 216 and the wired interface 218, in some implementations, the network interface 214 may include only the wireless interface or only the wired interface.

In one example, playback device 200 may be paired with one other playback device to play two separate audio components of audio content. For example, playback device 200 may be configured to play the left channel audio component, while other playback devices may be configured to play the right channel audio component, thereby creating or enhancing the stereo effect of the audio content. Paired playback devices (also referred to as "bonded playback devices") can also play audio content in synchronization with other playback devices.

In another example, playback device 200 may be acoustically combined with one or more other playback devices to form a single combined playback device. Because a federated playback device may have additional speaker drivers through which audio content may be rendered, a federated playback device may be configured to process and reproduce sound differently than a non-linked playback device or paired playback device. For example, if playback device 200 is a playback device designed to present low frequency range audio content (ie, a subwoofer), playback device 200 may be associated with a playback device designed to present full frequency range audio content. In such a case, when associated with the low frequency playback device 200, the full frequency range playback device may be configured to present only the mid and high frequency components of the audio content, while the low frequency range playback device 200 presents the low frequency components of the audio content. A federated playback device can also be paired with a single playback device or another federated playback device.

For example, SONOS Corporation currently offers (or has already publicly offered) certain playback devices including "PLAY: 1", "PLAY: 3", "PLAY: 5", "PLAYBAR", "CONNECT: AMP", "CONNECT", and "SUB". Additionally or alternatively, any other past, present and/or future playback devices may be used to implement playback devices of the example embodiments disclosed herein. Additionally, it should be understood that the playback device is not limited to the example or SONOS product offering shown in FIG. 2 . For example, playback devices may include wired or wireless headphones. In another example, the playback device may include or interact with a docking station for a personal mobile media playback device. In yet another example, the playback device may be integrated into another device or component such as a television, lighting fixture, or some other device for indoor or outdoor use.

b. Example playback area configuration

Referring back to the media playback system 100 of FIG. 1, an environment may have one or more playback zones, each playback zone having one or more playback devices. The media playback system 100 may be established with one or more playback zones, after which one or more zones may be added or removed to achieve the example configuration shown in FIG. 1 . Each zone can be named after a different room or space - such as an office, bathroom, master bedroom, bedroom, kitchen, dining room, living room and/or balcony. In one case, a single playback zone may include multiple rooms or spaces. In another case, a single room or space may include multiple playback zones.

As shown in Figure 1, the balcony, dining room, kitchen, bathroom, office, and bedroom areas each have one playback device, while the living room and master bedroom areas each have multiple playback devices. In the living room area, playback devices 104, 106, 108, and 110 may be configured: as individual playback devices, as one or more bundled playback devices, as one or more combined playback devices, or the like Any combination to play audio content synchronously. Similarly, in the case of a master bedroom, playback devices 122 and 124 may be configured to play audio content synchronously as separate playback devices, as bundled playback devices, or as joint playback devices.

In one example, one or more playback zones in the environment of FIG. 1 may each be playing different audio content. For example, a user may be grilling in the balcony area and listening to hip hop music being played by playback device 102 , while another user may be preparing food in the kitchen area and listening to classical music being played by playback device 114 . In another example, a playback zone may play the same audio content in synchronization with another playback zone. For example, a user may be in an office area where playback device 118 is playing the same rock music that playback device 102 in the balcony area is playing. In such a case, playback device 102 and playback device 118 may play rock music synchronously so that the audio being played loudly can be seamlessly (or at least substantially seamless) enjoyed by the user as the user moves between different playback zones content. Synchronization between playback zones may be accomplished in a manner similar to synchronization between playback devices, as described in previously referenced US Patent No. 8,234,395.

As noted above, the zone configuration of the media playback system 100 can be dynamically modified, and in some embodiments, the media playback system 100 supports a number of configurations. For example, if a user physically moves one or more playback devices to or from a zone, the media playback system 100 may be reconfigured to accommodate the change. For example, if a user physically moves playback device 102 from a balcony area to an office area, the office area may now include both playback device 118 and playback device 102 . If desired, playback device 102 may be paired or grouped together with the office area and/or renamed via control devices such as control device 126 and control device 128 . On the other hand, if one or more playback devices are moved to a particular area of the home environment that is not already a playback area, a new playback area may be created for that particular area.

Furthermore, the different playback zones of the media playback system 100 may be dynamically combined into zone groups or divided into separate playback zones. For example, the dining room area and the kitchen area 114 may be combined into a block for a dinner party, so that the playback devices 112 and 114 may simultaneously present audio content. On the other hand, if a user wishes to listen to music in the living room space and another user wishes to watch television, the living room area may be divided into a television area including playback device 104 and a listening area including playback devices 106 , 108 and 110 .

c. Example control device

FIG. 3 shows a functional block diagram of an example control device 300 that may be configured as one or both of control device 126 and control device 128 of media playback system 100 . The control device 300 may also be referred to as the controller 300 . As shown, control device 300 may include processor 302 , memory 304 , network interface 306 , user interface 308 . In one example, the control device 300 may be a dedicated controller for the media playback system 100 . In another example, the control device 300 may be a network device, such as an iPhone ^™ , iPad ^™ , or any other smartphone, tablet, or network device (eg, a networked computer such as a PC) that can install a media playback system controller application software or Mac ^TM ).

The processor 302 may be configured to perform functions related to facilitating user access, control, and configuration of the media playback system 100 . Memory 304 may be configured to store instructions executable by processor 302 to perform those functions. Memory 304 may also be configured to store media playback system controller application software and other data associated with media playback system 100 and users.

In one example, the network interface 306 may be based on industry standards (eg, infrared, radio, wired standards including IEEE 802.3, wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communication standards, etc.). Network interface 306 may provide a means for controlling device 300 to communicate with other devices in media playback system 100 . In one example, data and information (eg, such as state variables) may be communicated between control device 300 and other devices via network interface 306 . For example, the control device 300 may receive the playback zone and zone group configuration in the media playback system 100 from the playback device or another network device via the network interface 306 or the control device 300 may convert the playback zone in the media playback system 100 and the zone group via the network interface 306 The block configuration is sent to another playback device or network device. In some cases, the other network device may be another control device.

Playback device control commands such as volume controls and audio playback controls may also be communicated from the control device 300 to the playback device via the network interface 306 . As noted above, the user may also use the control device 300 to perform changes to the configuration of the media playback system 100 . Configuration changes may include: adding one or more playback devices to or removing one or more playback devices from a zone; adding one or more zones to or removing one or more from a zone group form a bound or joint player; detach one or more playback devices from a bound or joint player, etc. Therefore, the control device 300 may sometimes be referred to as a controller, regardless of whether the control device 300 is a dedicated controller or a network device with the media playback system controller application software installed.

The user interface 308 of the control device 300 may be configured to facilitate user access and control of the media playback system 100 by providing a controller interface, such as the controller interface 400 shown in FIG. 4 . The controller interface 400 includes a playback control area 410 , a playback area area 420 , a playback status area 430 , a playback queue area 440 , and an audio content source area 450 . The illustrated user interface 400 is merely a user that may be provided on a network device such as the control device 300 of FIG. 3 (and/or the control devices 126 and 128 of FIG. 1 ) and accessed by a user to control a media playback system such as the media playback system 100 An example of an interface. Alternatively, other user interfaces of different formats, styles and interaction sequences may be implemented on one or more network devices to provide comparable control access to the media playback system.

Playback control area 410 may include controls for playing or pausing playback devices in a selected playback zone or group, fast forwarding, rewinding, skipping to next track, skipping to previous track, entering/exiting random mode, entering /exit repeat mode, optional (eg by touch or by using cursor) icons to enter/exit crossfade mode. Playback control area 410 may also include selectable icons for modifying equalization settings and playback volume, among other possibilities.

Playback zone area 420 may include a representation of the playback zone within media playback system 100 . In some embodiments, the graphical representation of the playback zone may be selectable to generate additional selectable icons to manage or configure playback zones in the media playback system, eg, creation of binding zones, creation of zones, zone creation Separation of groups and renaming of blocks, among other possibilities.

For example, as shown, a "group" icon may be provided within each of the graphical representations of the playback area. A "group" icon positioned within the graphical representation of a particular zone may be selectable to yield options for selecting one or more other zones in the media playback system to group with the particular zone. Once grouped, playback devices in a zone that have been grouped with a particular zone will be configured to play the audio content in synchronization with the playback devices in the particular zone. Similarly, a "group" icon can be provided within the graphical representation of the block. In this case, the "group" icon may be selectable to generate an option to deselect one or more zones in the block group to be removed from the block group. Other interactions and implementations for grouping and ungrouping zones via a user interface such as user interface 400 are also possible. The representation of the playback zone in the playback zone area 420 may be dynamically updated as the playback zone or zone group configuration is modified.

The playback status area 430 may include a graphical representation of the audio content currently being played, previously played, or scheduled to be played next in the selected playback zone or group of zones. The selected playback zone or group of zones may be visually distinguished on a user interface, eg, within playback zone area 420 and/or playback status area 430. The graphical representation may include track title, artist name, album title, album year, track length, and other relevant information useful for the user to know when to control the media playback system via user interface 400 .

Playback queue area 440 may include a graphical representation of the audio content in the playback queue associated with the selected playback zone or group of zones. In some embodiments, each playback zone or zone group may be associated with a playback queue that contains information corresponding to zero or more audio items for playback by the playback zone or zone group. For example, each audio item in the playback queue may include a Uniform Resource Identifier (URI), Uniform Resource Locator (URL), or some other identifier that may be used by playback devices in a playback zone or set of zones to retrieve data from Local audio content sources or networked audio content sources find and/or retrieve audio items, possibly for playback by playback devices.

In one example, a playlist may be added to the playback queue, in which case information corresponding to each audio item in the playlist may be added to the playback queue. In another example, audio items in the playback queue may be saved as a playlist. In yet another example, playback is performed when a playback zone or group of zones is continuously playing streaming audio content—eg, an Internet radio that could be played continuously until otherwise stopped, rather than playing discrete audio items with playback durations. Queues can be empty or filled but "not in use". In alternative embodiments, the playback queue may include Internet radio and/or other streaming audio content items and the playback queue is "in use" when the playback zone or group of zones is playing those items. Other examples are also possible.

When a playback zone or zone is "grouped" or "ungrouped", the playback queue associated with the affected playback zone or zone may be cleared or re-associated. For example, if a first playback zone that includes a first playback queue is grouped with a second playback zone that includes a second playback queue, the created zone group may have an associated playback queue that originally Empty, contains audio items from the first playback queue (for example, if the second playback area is added to the first playback area), contains audio items from the second playback queue (for example, if the first playback area is added to the first playback area) two playback areas), or a combination of audio items from both the first playback queue and the second playback queue. Subsequently, if the established zone group is ungrouped, the resulting first playback zone may be re-associated with the previous first playback queue, or may be associated with a new playback queue that is empty or Contains audio items from the playback queue associated with the established chunk before it was ungrouped. Similarly, the resulting second playback zone can be re-associated with the previous second playback queue, or with a new playback queue that is either empty or contains data from the zone set established at the time of cancellation The audio items of the playback queue associated with the established block before the grouping. Other examples are also possible.

Referring back to user interface 400 of FIG. 4, the graphical representation of audio content in playback queue area 440 may include track name, artist name, track length, and other relevant information associated with the audio content in the playback queue. In one example, the graphical representation of the audio content may be selectable to generate additional selectable icons to manage and/or manipulate the playback queue and/or audio content presented in the playback queue. For example, the rendered audio content may be removed from the playback queue, moved to a different position within the playback queue, or selected to be played immediately or after any currently playing audio content, among other possibilities. A playback queue associated with a playback zone or zone may be stored in memory on one or more playback devices in the playback zone or zone, in memory on playback devices not in the playback zone or zone and/or or in memory on some other specified device. Playback of such a playback queue may involve one or more playback devices playing back the queue's media items, possibly in sequential order or random order.

Audio content sources area 450 may include a graphical representation of selectable audio content sources from which audio content may be retrieved and played by the selected playback zone or group of zones. A discussion of audio content sources can be found in the following sections.

5 depicts a smartphone 500 that includes one or more processors, tangible computer-readable memory, a network interface, and a display. Smartphone 500 may be an example implementation of control device 126 or 128 of FIG. 1 or control device 300 of FIG. 3 or other control devices described herein. By way of example, reference will be made to smartphone 500 and certain control interfaces, prompts, and other graphical elements that smartphone 500 may display when operating as a control device of a media playback system (eg, media playback system 100). Within examples, such interfaces and elements may be displayed by any suitable control device, such as a smartphone, tablet computer, laptop or desktop computer, personal media player or remote control device.

When operating as a control device of a media playback system, smartphone 500 may display one or more controller interfaces, such as controller interface 400 . Similar to playback control area 410, playback area area 420, playback status area 430, playback queue area 440, and/or audio content source area 450 of FIG. 4, smartphone 500 may display one or more corresponding interfaces, such as playback control interface, playback area interface, playback state interface, playback queue interface and/or audio content source interface. An example control device might utilize, for example, a smartphone or other handheld device to display a separate interface (rather than an area) with a relatively limited screen size.

d. Sample audio content source

As noted previously, one or more playback devices in a zone or group of zones may be configured to retrieve audio content for playback from various available audio content sources (eg, according to a corresponding URI or URL of the audio content). In one example, the audio content may be retrieved by the playback device directly from the corresponding audio content source (eg, line-in connection). In another example, the audio content may be provided to a playback device over a network via one or more other playback devices or network devices.

Example audio content sources may include: the memory of one or more playback devices in a media playback system such as media playback system 100 of FIG. 1 , one or more network devices (eg, such as a control device, a network-enabled personal computer, or a local music library on a network attached storage device (NAS), a streaming audio service that provides audio content via the Internet (e.g., the cloud), or an audio source connected to a media playback system via a playback device or a line-in connection on a network device, and other possibilities.

In some implementations, audio content sources may be added or removed from a media playback system, such as media playback system 100 of FIG. 1, on a regular basis. In one example, indexing audio items may be performed whenever one or more audio content sources are added, removed, or updated. Indexing audio items may involve: scanning for identifiable audio items in all folders/directories shared on a network accessible by playback devices in a media playback system; and generating or updating an audio content database containing Metadata (eg, name, artist, album, track length, etc.) and other associated information such as the URI or URL of each identifiable audio item found. Other examples for managing and maintaining audio content sources are also possible.

e. Example calibration sequence

As mentioned above, an example calibration process may involve one or more playback devices emitting calibration sounds, which may be detected by the recording device (or recording devices).

In some embodiments, the detected calibration sound may be analyzed over the frequency range (ie, the calibration range) over which the playback device is to be calibrated. Therefore, the specific calibration sound emitted by the playback device covers the calibration frequency range. The calibrated frequency range may include the range of frequencies that the playback device is capable of emitting (eg, 15 Hz to 30,000 Hz), and may include frequencies that are considered to be within the range of human hearing (eg, 20 Hz to 20,000 Hz). By emitting and then detecting calibration sounds covering such a frequency range, a frequency response including this range can be determined for the playback device. Such a frequency response may represent the environment in which the playback device emits calibrated sounds.

In some embodiments, the playback device may repeatedly emit the calibration sound during the calibration process such that the calibration sound covers the calibration frequency range during each repetition. Using a moving microphone, repetitions of the calibration sound are continuously detected at different physical locations within the environment. For example, a playback device may emit periodic calibration sounds. Each cycle of the calibration sound may be detected by the recording device at a different physical location within the environment, providing a sample (ie, representing a repeating frame) at that location. Such calibration sounds may thus facilitate a spatially averaged calibration of the environment. When multiple microphones are used, each microphone may cover a corresponding portion of the environment (possibly with some overlap).

Furthermore, the recording device can measure both moving and stationary samples. For example, the recording device may move within the environment while one or more playback devices output calibration sounds. During such movement, the recording device may pause at one or more locations to measure stationary samples. Such positions may correspond to preferred listening positions. In another example, the first recording device and the second recording device may include a first microphone and a second microphone, respectively. When the playback device emits the calibration sound, the first microphone may move and the second microphone may remain stationary, possibly at a particular listening position within the environment (eg, a favorite chair).

In some cases, one or more playback devices may join a group, such as a binding zone or zone group. In such a case, the calibration process may calibrate one or more playback devices as a group. Example groupings include block or bond pairs, and other example configurations.

The one or more playback devices being calibrated may initiate the calibration process based on the triggering condition. For example, a recording device, such as the control device 126 of the media playback system 100, may detect a trigger condition that causes the recording device to initiate a response to one or more playback devices (eg, one or more of playback devices 102-124). calibration. Alternatively, the playback device of the media playback system may detect such a trigger condition (and possibly forward an indication of the trigger condition to the recording device).

In some implementations, detecting a trigger condition may involve detecting input data indicating selection of a selectable control. For example, a recording device such as control device 126 may display an interface (eg, control interface 400 of FIG. 4 ) that includes one or more controls that, when selected, initiate a playback device or group (eg, zone) of playback devices calibration.

To illustrate such controls, FIG. 6 shows a smartphone 500 displaying an example control interface 600 . Control interface 600 includes a graphics area 602 that prompts to click selectable controls 604 (start) when ready. When selected, selectable control 604 may initiate a calibration process. As shown, selectable controls 604 are button controls. Although a button control is shown by way of example, other types of controls are also contemplated.

The control interface 600 also includes a graphics area 606 that includes a video depicting how to assist the calibration process. Some calibration procedures may involve moving the microphone within the environment to obtain samples of the calibration sound at multiple physical locations. To prompt the user to move the microphone, the control device may display a video or animation depicting one or more steps to be performed during calibration.

To illustrate the movement of the control device during calibration, FIG. 7 shows the media playback system 100 of FIG. 1 . FIG. 7 shows a path 700 along which a recording device (eg, control device 126 ) may travel during calibration. As mentioned above, the recording device may instruct in various ways how to perform such movements, eg by means of video or animation or the like. The recording device may detect iterations of calibration sounds emitted by one or more playback devices of the media playback system 100 at various points along the path 700, which may facilitate calibration of the spatial average of those playback devices.

In other examples, detecting a trigger condition may involve the playback device detecting that the playback device has become uncalibrated, possibly due to moving the playback device to a different location. For example, the playback device may detect physical movement via one or more sensors (eg, accelerometers) that are sensitive to movement. As another example, a playback device may detect that it has been moved to a different zone (eg, from a "kitchen" zone to a "living room" zone), possibly by receiving from the control device causing the playback device to leave the first zone and Moved to a different area by adding instructions to the second area.

In a further example, detecting a trigger condition may involve a recording device (eg, a control device or a playback device) detecting a new playback device in the system. Such playback devices may not have been calibrated for the environment. For example, a recording device may detect a new playback device as part of a setup process of the media playback system (eg, the process of configuring one or more playback devices into the media playback system). In other cases, the recording device may detect a new playback device by detecting input data indicative of a request to configure a media playback system (eg, a request to configure a media playback system with additional playback devices).

In some cases, the first recording device (or another device) may instruct one or more playback devices to emit calibration sounds. For example, a recording device such as control device 126 of media playback system 100 may send a command to cause a playback device (eg, one of playback devices 102-124) to emit calibration sounds. The control device may send commands via a network interface (eg, a wired network interface or a wireless network interface). The playback device may receive such commands, possibly via a network interface, and responsively emit calibration sounds.

The acoustics of the environment may vary with location within the environment. Due to this change, some calibration procedures can be improved by positioning the playback device to be calibrated within the environment in the same way that the playback device is operated later. In this position, the environment may affect the calibration sound emitted by the playback device in a similar way that the environment will affect playback during operation.

Additionally, some example calibration procedures may involve one or more recording devices detecting calibration sounds at multiple physical locations within the environment, which may further help capture acoustic variability within the environment. To facilitate detection of calibration sounds at multiple points within the environment, some calibration procedures involve moving microphones. For example, the microphone that is detecting the calibration sound may move within the environment while the calibration sound is being emitted. Such movement may facilitate detection of calibration sounds at multiple physical locations within the environment, which may provide a better understanding of the overall environment.

In some implementations, one or more playback devices may repeatedly emit the calibration sound during the calibration process such that the calibration sound covers the calibration frequency range during each repetition. Using a moving microphone, repetitions of the calibration sound are detected at different physical locations within the environment, providing samples that are spaced out throughout the environment. In some cases, the calibration sound may be a periodic calibration signal, where each cycle covers a calibration frequency range.

To facilitate determination of the frequency response, the calibration sound should be emitted at each frequency with sufficient energy to overcome the background noise. To increase the energy at a given frequency, the tones at that frequency can be emitted for longer durations. However, by extending the period of the calibration sound, the spatial resolution of the calibration process is reduced because the moving microphone moves farther during each period (assuming a relatively constant velocity). As another technique for increasing the energy at a given frequency, playback devices can increase the intensity of the tone. However, in some cases, attempting to emit enough energy for a short period of time can damage the speaker drivers of the playback device.

Some implementations may balance these considerations by instructing the playback device to emit a calibration sound having a period of approximately 3/8 second duration (eg, in the range of 1/4 second to 1 second duration). In other words, the calibration sound can be repeated at a frequency of 2Hz to 4Hz. Such durations can be long enough to provide enough energy tones at each frequency to overcome background noise in typical environments (eg, quiet rooms), but short enough to keep spatial resolution within acceptable limits within (eg, less than a few feet, assuming normal walking speed).

In some embodiments, one or more playback devices may emit a hybrid calibration sound that combines the first and second components having corresponding waveforms. For example, an example hybrid calibration sound may include a first component with noise at certain frequencies and a second component (eg, a swept sine) swept across other frequencies. The noise component may cover the relatively lower frequencies of the calibration frequency range (eg, 10 Hz to 50 Hz), while the scan signal component covers the higher frequencies of the range (eg, above 50 Hz). Such a mixed calibration sound can combine the advantages of its component signals.

A sweep signal (eg, a chirp or sweep sine) is a waveform whose frequency increases or decreases over time. Including such a waveform as a component of the mixed calibration sound may facilitate coverage of the calibration frequency range, as the scan signal may be selected to increase or decrease within the calibration frequency range (or a portion thereof). For example, the chirp emits each frequency within the chirp for a relatively short period of time, allowing the chirp to cover the calibration range more efficiently relative to some other waveform. FIG. 8 shows a graph 800 illustrating an example chirp. As shown in Figure 8, the frequency of the waveform increases with time (plotted on the x-axis), and a tone is emitted at each frequency over a relatively short period of time.

However, because each frequency within a chirp is emitted in a relatively short duration, the amplitude (or sound intensity) of the chirp must be relatively high at low frequencies to overcome typical background noise. Some speakers may not be able to output such high-intensity tones without risk of damage. Furthermore, such high-intensity tones can be unpleasant within the audible range of the playback device, as would be expected during a calibration process involving moving microphones. Therefore, some embodiments of the calibration sound may not include chirps that extend to relatively low frequencies (eg, below 50 Hz). Alternatively, the chirp or sweep signal may cover frequencies between a relatively low threshold frequency (eg, frequencies of about 50 Hz to 100 Hz) and the maximum value of the calibrated frequency range. The maximum value of the calibration range may correspond to the physical capability of the channel from which the calibration sound is emitted, which may be 20000 Hz or higher.

The scanning signal can also facilitate the inversion of phase distortion caused by moving microphones. As mentioned above, moving the microphone induces phase distortion, which can interfere with the determination of the frequency response from the detected calibration sound. However, with the scanning signal, the phase of each frequency is predictable (in terms of Doppler shift). This predictability helps to invert the phase distortion so that the detected calibration sound can be correlated with the emitted calibration sound during analysis. Such correlations can be used to determine the influence of the environment on the calibrated sound.

As mentioned above, the sweep signal can cause the frequency to increase or decrease over time. In some embodiments, the recording device may instruct one or more playback devices to emit chirps from the maximum value (or above) of the calibration range down to a threshold frequency (or below). Because of the physical shape of the human ear canal, a falling chirp may be more pleasant to some listeners than an upward chirp. Although some implementations may use a falling scan signal, a rising scan signal may also be effective for calibration.

As mentioned above, the example calibration sound may include noise components in addition to the scan signal components. Noise refers to a random signal that, in some cases, is filtered to have equal energy per octave. In embodiments where the noise component is periodic, the noise component of the mixed calibration sound may be considered pseudo-random. The noise component of the calibration sound may be emitted for substantially the entire period or repetition of the calibration sound. This allows each frequency covered by the noise component to be emitted for a longer duration, which reduces the signal strength typically required to overcome background noise.

Furthermore, the noise component may cover a smaller frequency range than the chirp component, which may increase the sound energy at each frequency in the range. As mentioned above, the noise component may cover frequencies between the minimum value of the frequency range and a threshold frequency, which may be, for example, a frequency of about 50 Hz to 100 Hz. As with the maximum value of the calibration range, the minimum value of the calibration range may correspond to the physical capabilities of the channel from which the calibrated sound is emitted, which may be 20 Hz or lower.

FIG. 9 shows a graph 900 illustrating example Brownian noise. Brownian noise is a noise based on Brownian motion. In some cases, the playback device may emit a calibration sound that includes Brownian noise in its noise component. Brownian noise has "soft" properties similar to waterfalls or heavy precipitation, which may be pleasant to some listeners. While some implementations may implement the noise component using Brownian noise, other implementations may implement the noise component using other types of noise, such as pink noise or white noise. As shown in Figure 9, the intensity of the example Brownian noise is reduced by 6 dB per octave (20 dB per decade).

Some implementations of mixing calibration sounds may include transition frequency ranges where noise components and sweep frequency components overlap. As described above, in some examples, the control device may instruct the playback device to emit a calibration sound that includes a first component (eg, a noise component) and a second component (eg, a scan signal component). The first component may include noise with a frequency between a minimum of the calibration frequency range and a first threshold frequency, and the second component may sweep frequencies between the second threshold frequency and a maximum of the calibration frequency range.

In order for these signals to overlap, the second threshold frequency may be a lower frequency than the first threshold frequency. In such a configuration, the transition frequency range includes frequencies between the second threshold frequency and the first threshold frequency, which may be, for example, 50 Hz to 100 Hz. By overlapping these components, the playback device can avoid potentially unpleasant sounds associated with harsh transitions between the two types of sounds.

10A and 10B illustrate components of an example mixed calibration signal covering a calibration frequency range 1000. FIG. 10A shows a first component 1002A (ie, a noise component) and a second component 1004A of an example calibration sound. Component 1002A covers frequencies from minimum value 1006A of calibration range 1000 to first threshold frequency 1008A. Component 1004A covers frequencies from the second threshold 1010A to the maximum value of the calibration frequency range 1000. As shown, threshold frequency 1008A and threshold frequency 1010A are the same frequency.

FIG. 10B shows a first component 1002B (ie, a noise component) and a second component 1004B of another example calibration sound. Component 1002B covers frequencies from minimum value 1006B of calibration range 1000 to first threshold frequency 1008B. Component 1004A covers frequencies from second threshold 1010B to maximum value 1012B of calibration frequency range 1000. As shown, threshold frequency 1010B is a lower frequency than threshold frequency 1008B such that component 1002B and component 1004B overlap in a transition frequency range extending from threshold frequency 1010B to threshold frequency 1008B.

FIG. 11 illustrates one example iteration (eg, cycle or loop) of the example mixed calibration sound represented as frame 1100 . Frame 1100 includes scan signal component 1102 and noise component 1104 . The scan signal component 1102 is shown as a downward sloping line to show the scan signal falling within the frequency of the calibration range. Noise components 1104 are shown as regions to illustrate low frequency noise throughout frame 1100 . As shown, the scan signal component 1102 and the noise component overlap in the transition frequency range. The period 1106 of the calibration sound is approximately 3/8 second (eg, in the range of 1/4 second to 1/2 second), which in some implementations is sufficient time to cover the calibration frequency range for mono.

FIG. 12 shows an example periodic calibration sound 1200 . Five iterations (eg, cycles) of mixed calibration sound 1100 are represented as frames 1202 , 1204 , 1206 , 1208 , and 1210 . In each iteration or frame, the periodic calibration sound 1200 uses two components (eg, a noise component and a scan signal component) to cover the calibration frequency range.

In some embodiments, spectral adjustments may be applied to the calibration sound to give the calibration sound a desired shape or roll off, which may avoid overloading the speaker drivers. For example, the calibration sound can be filtered to roll off at 3dB per octave or 1/f. Such spectral adjustments may not be suitable for changing low frequencies to prevent overloading the speaker drivers.

In some embodiments, calibration sounds may be pre-generated. Such pre-generated calibration sounds may be stored on the control device, playback device, or server (eg, a server providing cloud services to the media playback system). In some cases, the control device or server may send the pre-generated calibration sound to the playback device via a network interface, and the playback device may retrieve the calibration sound via its own network interface. Alternatively, the control device may send an indication (eg, a URI) of the source of the calibration sound to the playback device, which may be used by the playback device to obtain the calibration sound.

Alternatively, the control device or playback device may generate calibration sounds. For example, for a given calibration range, the control device may generate noise covering at least frequencies between the minimum value of the calibration frequency range and the first threshold frequency and frequencies covering at least the second threshold frequency and the maximum value of the calibration frequency range of sweep sine. The control device can combine the sweep sine and noise into a periodic calibration sound by applying a cross-filtering function. The cross filtering function may combine the portion of the generated noise including frequencies below the first threshold frequency with the portion of the generated sweep sine including frequencies above the second threshold frequency to obtain the desired calibration sound. The device for generating the calibration sound may have analog circuitry and/or a digital signal processor to generate and/or combine components of the mixed calibration sound.

Additional example calibration procedures are described in: US Patent Application No. 14/805,140, filed Jul. 21, 2015, entitled "HybridTest Tone For Space-Averaged Room Audio Calibration Using A MovingMicrophone," in 2015 U.S. Patent Application Serial No. 14/805,340, entitled "ConcurrentMulti-Loudspeaker Calibration with a Single Measurement," filed July 21, and U.S. Patent Application No. 14/805,340, entitled "Facilitating Calibration of an AudioPlayback Device," filed September 24, 2015 Patent Application No. 14/864,393, the entire contents of which are incorporated herein by reference.

Calibration may be facilitated via one or more control interfaces as displayed by one or more devices. Example interfaces are described in US Patent Application Serial No. 14/696,014, entitled "Speaker Calibration," filed April 24, 2015, and "Speaker Calibration UserInterface," filed August 14, 2015 ," U.S. Patent Application Serial No. 14/826,873, the entire contents of which are incorporated herein.

Turning now to a few example implementations, implementations 1300, 1900, and 2000 shown in Figures 13, 19, and 20, respectively, present example implementations of the techniques described herein. These example embodiments may be implemented in systems including, for example, the media playback system 100 of FIG. 1, one or more playback devices 200 of FIG. 2, or one or more control devices 300 of FIG. 3, as well as other devices described herein and/or other be implemented within the operating environment of a suitable device. Furthermore, operations shown by way of example as being performed by the media playback system may be performed by any suitable device, such as a playback device or control device of the media playback system. Implementations 1300, 1900, and 2000 may include one or more operations, functions, or actions as illustrated by one or more of the blocks illustrated in Figures 13, 19, and 20. Although blocks are shown in sequential order, these blocks can also be executed in parallel and/or in a different order than described herein. Additionally, various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based on the desired implementation.

Additionally, for the implementations disclosed herein, the flowchart illustrates the functionality and operation of one possible implementation of the present embodiment. In this regard, each block may represent a module, segment, or portion of program code, which comprises one or more instructions executable by a processor for implementing the specified logical function or step in the process. The program code may be stored on any type of computer-readable medium, for example, storage devices including magnetic disks or hard drives. Computer-readable media may include non-transitory computer-readable media, eg, computer-readable media that store data for a short period of time, such as register memory, processor cache, and random access memory (RAM). Computer-readable media may also include non-transitory media, such as secondary or persistent long-term storage devices such as read only memory (ROM), optical or magnetic disks, compact disk read only memory (CD-ROM). The computer readable medium can also be any other volatile or nonvolatile storage system. Computer-readable media may be considered, for example, computer-readable storage media or tangible storage devices. Additionally, for the implementations disclosed herein, each block may represent a circuit that is wired to perform the specified logical function in the process. III. Example Techniques for Facilitating Spatial Calibration

As described above, embodiments described herein may facilitate calibration of one or more playback devices by determining spatial calibration. FIG. 13 illustrates an example implementation 1300 by which a media playback system facilitates such calibration.

a. Detect trigger conditions

At block 1302, implementation 1300 involves detecting a triggering condition. For example, a networked microphone device may detect a trigger condition that initiates calibration of the media playback system (or possibly a group of playback devices in the media playback system). Example networked microphone devices include any suitable device having a network interface and a microphone. For example, a playback device (eg, playback device 200) and a control device (eg, control device 300) may each operate as networked microphone devices. Other example networked microphone devices include control devices 126 and 128 of FIG. 1 .

Trigger conditions can initiate calibration of multiple audio drivers. In some cases, multiple audio drivers can be accommodated in a single playback device. For example, a sound bar-type playback device may include multiple audio drivers (eg, nine audio drivers). In other cases, multiple audio drivers may be divided between two or more playback devices. For example, a sound bar with multiple audio drivers may be calibrated with one or more other playback devices, each playback device having one or more corresponding audio drivers. Some example playback devices include multiple different types of audio drivers (eg, tweeters and woofers that may have different sizes).

The particular playback device (and audio driver) that is calibrated may correspond to a zone of the media playback system. For example, an example trigger condition may initiate calibration of a given zone of the media playback system (eg, the living room zone of the media playback system 100 shown in FIG. 1 ). According to this example, the living room area includes playback devices 104, 106, 108, and 110 that together include multiple audio drivers, and example trigger conditions may thus initiate calibration of the multiple audio drivers.

As described above in connection with the example calibration sequence, various trigger conditions are contemplated herein. Some example trigger conditions include input data instructing the media playback system to initiate calibration. Such input data may be received via a user interface of the networked microphone device (eg, control interface 600 of FIG. 6 ), as shown in FIG. 6 , or possibly via communication of instructions to the networked microphone device and/or the playback device being calibrated. another device to receive.

Other example trigger conditions may be based on sensor data. For example, sensor data from an accelerometer or other suitable sensor may indicate that a given playback device has moved, which may prompt that playback device (and possibly other playback devices associated with the given playback device, such as bindings with the playback device) playback devices in a fixed zone or zone group).

Some trigger conditions may involve a combination of input data and sensor data. For example, sensor data may indicate changes in the operating environment of the media playback system, which may cause prompts to be displayed on networked microphone devices to initiate calibration. The media playback system may calibrate upon receipt of input data indicating confirmation to initiate calibration with a prompt.

Additional example trigger conditions may be based on changes in the configuration of the media playback system. For example, example trigger conditions include adding or removing playback devices from the media playback system (or groupings thereof). Other example triggering conditions include receiving new types of input content (eg, receiving multi-channel audio content).

In operation, multiple audio drivers may form multiple acoustic axes. For example, two playback devices, each with respective audio drivers, may form respective sound axes. In some cases, two or more audio drivers may be arranged to form an acoustic axis. For example, a playback device with multiple audio drivers (eg, a sound bar with nine audio drivers) may form multiple acoustic axes (eg, three acoustic axes). Any audio driver can contribute to any number of sound axes. For example, a given acoustic axis may be formed by the contributions of all nine audio drivers of the soundbar.

Each sound axis may correspond to a corresponding input channel of audio content. For example, an audio driver of a media playback system may form two sound axes corresponding to left and right channels of stereo content, respectively. As another example, an audio driver may form sound axes corresponding to respective channels of surround sound content (eg, center channel, front left channel, front right channel, rear left channel, and rear right channel).

Arranging two or more audio drivers to form a given acoustic axis may enable the two or more audio drivers to "direct" the sound output of the given acoustic axis in a particular direction. For example, where each of the soundbar's nine audio drivers contributes a portion of the sound axis corresponding to the left channel of the surround content, the nine audio drivers may be arranged in such a way (that is, acoustically summed , possibly using DSP): The net polar response of the nine audio drivers directs the sound to the left. Simultaneously with the sound axis corresponding to the left channel, the nine audio drivers can also form the sound axis corresponding to the center channel and the right channel of the surround content to direct the sound to the center and the right, respectively.

The particular set of sound axes formed by the playback devices of the media playback system may be referred to as a playback configuration. In operation, a playback device of a media playback system may be configured for a given playback configuration of a number of possible playback configurations. Given a playback configuration, the audio drivers of the playback device may form a particular set of sound axes. In some cases, the configuration of the playback device as a new playback configuration may be used as a triggering condition to initiate calibration of the playback device.

For illustration, referring back to FIG. 1, the playback devices 104, 106, 108, and 110 of the living room area may be configured in multiple playback configurations. In a first playback configuration that may be associated with surround sound audio content, playback device 104 may form one or more sound axes (eg, front, left, and right channels), while playback devices 108 and 110 Corresponding sound axes (eg, left and right surround channels) are formed. Playback device 110 , being a subwoofer-type device, may contribute a separate low frequency acoustic axis or a low frequency portion of the acoustic axis formed by playback devices 104 , 106 and/or 108 . In another playback configuration, the audio drivers of playback devices 104, 106, 108, and 110 may combine to form sound axes corresponding to left and right channels of stereo audio content. Another playback configuration may involve the audio driver forming a single sound axis corresponding to mono audio content.

In operation, a playback device may utilize a given playback configuration depending on various factors. Such factors may include zone configuration (eg, whether the playback device is in a 5.1, 5.0 or other surround sound configuration, stereo pairing configuration, play bar only configuration, etc.). These factors may also include the specific type and capabilities of playback devices. These factors may also include the particular type of content provided (or expected to be provided) to the playback device. For example, the playback device may employ a first playback configuration when playing surround sound content and a further playback configuration when playing stereo content. As another example, a playback device may use a given playback configuration when playing music, and use another playback configuration when playing audio paired with video (eg, television content). Additional example playback configurations include any of the above-described example configurations with (or without) subwoofer-type playback devices, as adding (or subtracting) such devices from the playback configuration can change the acoustic characteristics and/or playback responsibilities in the playback configuration allocation.

Some example calibration sequences involve calibrating a playback device for multiple playback configurations. Such a calibration sequence may generate multiple calibration profiles that apply to playback devices in a given playback configuration. For example, a given calibration process may calibrate the living room area of the media playback system 100 for a surround sound playback configuration and a music playback configuration. In a surround sound playback configuration, the playback device in the living room area may apply a first calibration profile corresponding to the surround sound playback configuration (eg, adjust one or more of amplitude response, frequency response, phase, etc. or more filters). Likewise, in the music playback configuration, the playback device in the living room area may apply a second calibration profile corresponding to the music playback configuration.

b. Make multiple audio drivers emit calibrated audio

In Figure 13, at block 1304, implementation 1300 involves causing a plurality of audio drivers to emit calibration audio. For example, the NMD may instruct one or more playback devices that include multiple audio drivers to emit calibration audio via the multiple audio drivers. For example, control device 126 of media playback system 100 may send a command to cause a playback device (eg, one of playback devices 102-124) to issue calibration audio. The NMD may send commands via a network interface (eg, a wired network interface or a wireless network interface). The playback device may receive such commands, possibly via a network interface, and emit calibration audio in response.

The calibration audio may include one or more calibration sounds, such as frequency sweeps ("chirps"), brown noise or other types of noise or songs, and other example sounds. Additional details regarding example calibration sounds are described above in connection with the example calibration sequences described in Section II.e, and generally throughout this disclosure.

In some examples, the calibration audio is divided into frames. As shown in FIGS. 11 and 12 and described herein, a frame may represent an iteration (eg, cycle or loop) of an example calibration sound. When recorded, the frames may produce corresponding samples of calibration sounds as emitted by one or more audio drivers.

As mentioned above, in some cases the calibration sequence involves calibration of multiple acoustic axes. Example calibration audio for calibrating multiple acoustic axes may be divided into frames, where each frame includes calibration audio for each acoustic axis being calibrated. Thus, when recorded, each frame may include a sample of calibration audio produced by each acoustic axis. The frame can be repeated to produce multiple samples for each acoustic axis.

Each frame may be further divided into time slots in order to include calibration audio for each acoustic axis being calibrated. Each time slot may include calibration audio for the corresponding acoustic axis being calibrated. For example, an example frame of a playbar-type playback device (eg, playback device 104 shown in FIG. 1 ) forming three acoustic axes, such as left, right, and center channels, may include three time slots. For example, if a subwoofer-type device is to be used to calibrate the device, each frame may include four time slots, one for each acoustic axis formed by the playbar-type playback device, and one for each sound axis produced by the subwoofer sound axis. As another example, where a playbar-type playback device is calibrated with two additional playback devices producing corresponding acoustic axes (eg, rear left and right channels), each frame may include five time slots ( or six time slots if calibrated with a subwoofer).

As described above, each time slot may include calibration audio for the corresponding acoustic axis that is being calibrated. Calibration tones in each time slot may include frequency sweeps ("chirps"), brown noise, or other types of noise, among other examples. For example, referring back to Figures 11 and 12, the calibration audio in each sound may include a mix of calibration sounds. The time slots may occur sequentially in a known order to facilitate matching the time slots within the recorded calibration audio to the corresponding acoustic axes. Each time slot may have a known duration, which may also facilitate matching time slots within the recorded calibration audio to the corresponding acoustic axis. In other examples, each time slot and/or frame may include a watermark (eg, a specific sound pattern) for identifying the time slot or frame, which watermark may be used to match time slots within the recorded calibration audio to corresponding sound axis.

For illustration, FIG. 14 shows an example calibration audio 1400 . Calibration sound 1400 includes frames 1402 , 1404 and 1406 . Frames 1402, 1404 and 1406 are divided into respective three respective time slots. In particular, frame 1402 includes time slots 1402A, 1402B, and 1402C. Likewise, frames 1404 and 1406 include time slots 1404A, 1404B, and 1404C, and 1406A, 1406B, and 1406C, respectively. Each time slot includes an iteration of the mixed calibration sound 1100 of FIG. 11 . During the calibration process, the calibration sound in each time slot may be emitted by the corresponding sound axis (possibly formed via multiple audio drivers). For example, timeslots 1402A, 1404A, and 1406A may correspond to a first acoustic axis (eg, the left channel), while timeslots 1402B, 1404B, and 1406B correspond to a second acoustic axis (and timeslots 1402C, 1404C, and 1406C correspond to the first acoustic axis) three acoustic shafts). In this manner, when recorded, calibration audio 1400 may produce three samples per acoustic axis, assuming sufficient portions of frames 1402, 1404, and 1406 are recorded.

As described above, in some example calibration procedures, playback devices of a media playback system may be calibrated for multiple playback configurations. Alternatively, different playback configurations for sets of audio drivers may be calibrated in corresponding calibration sequences. An example calibration audio for calibrating multiple playback configurations may include a repeated series of frames. Each frame in the series may correspond to a corresponding playback configuration. For example, an example calibration audio for calibrating three playback configurations may include a series of three frames (eg, frames 1402, 1404, and 1406 of Figure 14).

As shown in FIG. 14, each frame of the series may be divided into time slots corresponding to the acoustic axis corresponding to the playback configuration of the frame. Since different playback configurations may result in different sets of acoustic axes, which may have different numbers of total axes, frames in a series may have different numbers of time slots. The series of frames can be repeated to produce multiple samples for each sound axis of each playback configuration.

c. Record calibration audio

In Figure 13, at block 1306, implementation 1300 involves recording the emitted calibration audio. For example, the NMD may record calibration audio as emitted by a playback device of a media playback system (eg, media playback system 100 ) via a microphone. As noted above, example NMDs include a control device (eg, control device 126 or 128 of FIG. 1 ), a playback device, or any suitable device that has a microphone or other sensor to record calibration audio. In some cases, multiple NMDs may record calibration audio via respective microphones.

In practice, some of the calibration sounds may be attenuated or drowned out by environmental or other conditions, which may interfere with the recording device recording all of the calibration sounds. In this way, the NMD may measure a portion of the calibration sound as emitted by the playback device of the media playback system. The calibration audio may be any of the example calibration sounds described above with respect to the example calibration process, as well as any suitable calibration sounds.

In some cases, one or more of the NMDs may remain more or less stationary while recording the calibration audio. For example, the NMD may be positioned at one or more specific locations (eg, preferred listening locations). Such positioning may aid in recording calibration audio as perceived by the listener at that particular location.

Certain playback configurations may suggest specific preferred listening positions. For example, a playback configuration corresponding to surround sound audio or video-coupled audio may suggest a location where the user will be watching television (eg, on a sofa or chair) while listening to the playback device. In some examples, the NMD may prompt to move to a specific location (eg, a preferred listening location) to begin calibration. When calibrating multiple playback configurations, the NMD may prompt to move to certain listening positions corresponding to each playback configuration.

To illustrate such a prompt, in FIG. 15 , smartphone 500 is displaying control interface 1500 including graphics area 1502 . Graphical area 1502 prompts to move to a specific location (ie, where in the room the user would normally watch television). Such prompts can be displayed to guide the user to start the calibration sequence at a preferred location. Control interface 1500 also includes selectable controls 1504 and 1506, which advance and reverse, respectively, in the calibration sequence.

FIG. 16 depicts smartphone 500 displaying control interface 1600 including graphics area 1602 . Graphics area 1602 prompts the user to raise the recording device to eye level. Such prompts can be displayed to guide the user to position the phone in a position that facilitates measurement of calibration audio. Control interface 1600 also includes selectable controls 1604 and 1606, which advance and reverse, respectively, in the calibration sequence.

Next, FIG. 17 depicts smartphone 500 displaying control interface 1700 including graphics area 1702 . Graphics area 1702 prompts the user to "set the best location" (ie, a preferred location in the environment). After smartphone 500 detects selection of selectable control 1704, smartphone 500 may begin measuring calibration audio at its current location (and possibly also instructing one or more playback devices to output calibration audio). As shown, the control interface 1700 also includes selectable controls 1706 that advance the calibration sequence (eg, by causing the smartphone to begin measuring calibration sounds at its current location, as with selectable controls 1704).

In FIG. 18 , smartphone 500 displays control interface 1800 including graphics area 1802 . Graphics area 1802 indicates that smartphone 500 is recording calibration audio. The control interface 1800 also includes an optional control 1804 that steps back in the calibration sequence.

d. Enables processing of recorded calibration audio

In Figure 13, at block 1308, implementing 1300 involves causing the recorded calibration audio to be processed. For example, the NMD can cause the processing device to process the recorded calibration audio. In some cases, the NMD may include processing equipment. Alternatively, the NMD may send the recorded audio to one or more other processing devices for processing. Example processing devices include playback devices, control devices, computing devices connected to the media playback system via a local area network, remote computing devices such as cloud servers, or any combination of the above.

The process of calibrating the audio may involve determining one or more calibrations for each of the plurality of acoustic axes. Each calibration of the multiple acoustic axes may involve modifying one or more of the amplitude response, frequency response, phase adjustment, or any other acoustic characteristic. Such modifications may spatially align multiple acoustic axes to one or more locations (eg, one or more preferred listening locations).

Such modifications may be applied using one or more filters implemented in DSP or as analog filters. The calibration data may include parameters used to implement the filter (eg, as coefficients of a biquad filter). Filtering may be applied per audio driver or per group of two or more drivers (eg, two or more drivers forming an acoustic axis or two or more of the same type of audio drivers, among other examples) device. In some cases, corresponding calibrations may be determined for multiple playback configurations that are calibrated.

The recorded calibration audio can be processed while recording or after recording. For example, where calibration audio is divided into frames, the frames may be sent to the processing device as they are recorded, possibly in sets of frames. Alternatively, after the playback device finishes emitting the calibration audio, the recorded frames may be sent to the processing device.

Processing may involve determining respective delays for each of the plurality of acoustic axes. Ultimately, such delays can be used to align the arrival times of the corresponding sounds from each acoustic axis at a particular location (eg, a preferred listening location). For example, a calibration profile for a given playback configuration may include filters that delay certain acoustic axes of the playback configuration to align the arrival times of the acoustic axes of the playback configuration at preferred listening locations. Sound axes can have different arrival times at certain locations because they are formed by audio drivers at different distances from the particular location. Furthermore, some acoustic axes may be directed away from certain locations (eg, left and right channels of a sound bar-type playback device) and thus be reflected by the environment before reaching certain locations. Such a sound path can increase the effective distance between the audio driver forming the sound axis and a particular location, which can result in a later arrival time compared to a sound axis with a more direct path. As mentioned above, for a surround sound playback configuration, such a preferred listening position may be a sofa or chair.

In an example, the processing device may divide the recorded audio into sections corresponding to different acoustic axes and/or playback configurations from which each section is emitted. For example, where the calibration sound emitted by the playback device is divided into frames, the processing device may divide the recorded audio into constituent frames. Where the calibration sound includes a series of frames, the processing device may attribute the frames from each series to the respective playback configuration corresponding to those frames. Furthermore, the processing device may divide each frame into respective time slots corresponding to each acoustic axis. As mentioned above, the playback device may issue frames and time slots in a known order, and each time slot may have a known duration to facilitate dividing the recorded audio into its component parts. In some examples, each time slot and/or frame may include a watermark identifying the time slot or frame, which watermark may be used to match the frame within the recorded calibration audio to the corresponding playback configuration and/or time The gap is matched to the corresponding acoustic axis.

The processing device can determine the impulse response for each acoustic axis. Each impulse response can be further processed by generating a frequency filtered response to divide the impulse response into frequency bands. Different types of audio drivers can be better aligned at different frequency bands. For example, mid-range woofers can line up nicely to form an acoustic axis in the 300Hz to 2.5kHz range. As another example, tweeters can line up well in the 8kHz to 14kHz range. With the example acoustic axis configured to form the center channel of a surround sound configuration, the acoustic axis should be largest on-axis and attenuated to the right and left. Conversely, for the acoustic axes of the left and right channels forming a surround sound configuration, each array should be attenuated (eg, zero) on-axis and maximized to the left or right, respectively. Outside of certain ranges, such as those provided above, the audio driver may also not form an acoustic axis in the intended direction. These frequency ranges are provided by way of example and can vary depending on the capabilities and characteristics of different audio drivers.

As another example, in a playback device with multiple audio drivers of different types (eg, tweeters and woofers), the processing device may determine three band-limited responses. Such responses may include full-range responses, responses covering the mid-range of the woofer (eg, 300 Hz to 2.5 kHz), and responses covering the high frequencies of the tweeter (eg, 8 kHz to 14 kHz). Such frequency filtered responses can facilitate further processing by representing each acoustic axis more clearly.

Processing the recorded audio may involve comparisons between the responses of each vocal axis. To facilitate such comparisons, the impulse responses for each time slot can be time aligned with each other (as they are emitted during different time periods). For example, the impulse response may be aligned with a first reference point such as the beginning of each time slot. Such temporal alignment of the impulse responses facilitates the identification of specific reference points in each response.

In an example implementation, the identification of a particular reference point in each response involves identifying a given second reference point in the impulse response of the reference acoustic axis. As an example, the reference acoustic axis may be the acoustic axis corresponding to the center channel of the surround sound system (eg, 3.0, 3.1, 5.0, 5.1, or other multi-channel playback configuration). This acoustic axis can be used as a reference acoustic axis because sound from this axis travels more directly to a generally preferred listening position than other acoustic axes (eg, the acoustic axis forming the left and right channels). The given second reference point in the impulse response may be the first peak. It can be assumed that the first peak corresponds to the direct signal (rather than reflections) from one or more audio drivers to the NMD. This given second reference point (ie, the first peak) is used as a reference for subsequent arrival times of other acoustic axes at the NMD.

In order to compare the time of arrival of the other acoustic axis at the NMD with the time of arrival of the reference acoustic axis at the NMD, the processing device may identify a second reference point in the other impulse response. These other second reference points correspond to the same second reference points in the reference acoustic axis. For example, if the first peak in the impulse response of the reference acoustic axis is used as a given second reference point, then the first peak in the other impulse responses is identified as the second reference point.

Given the approximate physical configuration of the plurality of audio drivers, a time window can be applied to limit the portion of each impulse response for which the second reference point is to be identified. For example, where the vocal axis forms the left, right and center channels, the impulse responses of the vocal axis forming the left and right channels may be restricted to the impulse response of the vocal axis forming the center channel The time window after the peak of . The sound from the sound axes forming the left and right channels travels outward left and right (rather than on-axis), so the peaks of interest will be the reflections of the sound from these axes by the environment. However, the acoustic axis forming the left surround channel and/or the right surround channel and/or the subwoofer channel may be physically closer to the NMD than the one or more audio drivers forming the center channel. In this way, the windows of the impulse responses corresponding to those axes may include time before and after a given reference point in the reference acoustic axis to account for the possibility of positive or negative delays relative to the reference acoustic axis.

Once the corresponding second reference point in the impulse response is identified, the corresponding arrival time of the sound from each acoustic axis at the NMD (ie, the microphone of the NMD) can be determined. In particular, the processing device may determine the respective arrival times at the microphones by comparing the respective differences of the first and second reference points in each impulse response.

Having determined the respective arrival times at the NMD of the sound from each acoustic axis, the processing device can determine the respective delay to apply to each acoustic axis. The processing device may determine the delay relative to the delay target. The delay target may be the acoustic axis with the latest arrival time. A sound axis used as a delay target may not receive any delay. Delays can be assigned to other sound axes to match the arrival time of the sound axis used as the delay target. The vocal axis forming the center channel cannot be used as a delay target in some cases, because vocal axis with a later arrival time cannot be assigned a "negative" delay to match the arrival time of the vocal axis forming the center channel.

In some cases, the delay for any given acoustic axis may be capped at a maximum delay threshold. Such capping may prevent problems where substantial delays cause significant mismatches between the audio content output by the sound axis and the video content coupled to the audio content (eg, lip sync problems). Such capping may only apply to playback configurations that include audio paired with video, since large delays may not affect the user experience when audio is not paired with video. Alternatively, if the video display is synchronized with one or more playback devices, the video may be delayed to avoid apparent mismatches between the audio content output by the sound axis and the video content coupled to the audio content, which can eliminate The need for a maximum latency threshold.

As mentioned above, the NMD recording the calibration audio may not perform some parts of the processing (or may not process the calibration audio at all). Specifically, the NMD may send data representing the recorded calibration audio to a processing device, possibly with one or more instructions on how to process the recorded calibration audio. In other cases, the processing device may be programmed to process the recorded calibration audio using certain techniques. In such embodiments, sending data representing recorded calibration audio (eg, data representing raw samples of calibration audio and/or data representing partially processed calibration audio) may cause the processing device to determine a calibration profile (eg, filtering device parameters).

e. Enables calibration of multiple acoustic axes

In Figure 13, at block 1310, implementing 1300 involves causing a plurality of acoustic axes to be calibrated. For example, the NMD may send calibration data to one or more playback devices forming multiple acoustic axes. Alternatively, the NMD may instruct another processing device to send the calibration data to the playback device. Such calibration data may enable one or more playback devices to calibrate multiple acoustic axes to a particular response.

As mentioned above, calibration of multiple acoustic axes may involve modifying one or more of the amplitude response, frequency response, phase adjustment, or any other acoustic characteristic. Such modifications may be applied using one or more filters implemented in DSP or as analog filters. The calibration data may include parameters used to implement the filter (eg, as coefficients of a biquad filter). Filtering may be applied per audio driver or per group of two or more drivers (eg, two or more drivers forming an acoustic axis or two or more of the same type of audio drivers, among other examples) device.

Calibrating the plurality of sound axes may include delaying the audio output of the plurality of sound axes according to respective determined delays of the sound axes. Such delays may be formed by having respective filters delay the audio output of the plurality of audio drivers according to respective determined delays of the plurality of acoustic axes. Among other examples, such a filter may implement a circular buffer delay line.

In some cases, the delay is dynamic. For example, the response of one axis may overlap the response of another axis within a given range, but the acoustic axes may have different arrival times (and thus indicate different delays). In such a case, the delay of each acoustic axis can be smoothed within the overlapping range. For example, delay curves can be implemented in ranges to smooth out delays. Such smoothing may improve the user experience by avoiding possible significant differences in delay between acoustic axes in overlapping ranges.

As mentioned above, in some cases the sound produced by certain acoustic axes may be previously reflected by the environment.

IV. Example Techniques to Facilitate Spectral Calibration Using Applied Spatial Calibration

As described above, embodiments described herein may facilitate calibration of one or more playback devices. FIG. 19 illustrates an example implementation 1900 by which a playback device facilitates spectral calibration using the applied spatial calibration.

a. Receive data representing one or more spatial calibrations

At block 1902, implementation 1900 involves receiving data representing an or spatial calibration. For example, a playback device (eg, any playback device of media playback system 100 in FIG. 1 or playback device 300 in FIG. 3 ) may receive representations of one or more via a network interface from a device such as a processing device or NMD, as well as other possible sources Data for multiple spatial calibrations (eg, any of the multiple calibrations described above in connection with the implementation 1300 of FIG. 13 ). Each calibration may be predetermined by a calibration sequence, such as the example calibration sequence described above.

Calibration may include one or more filters. Such filters may modify one or more of the amplitude response, frequency response, phase adjustment, or any other acoustic characteristic. Furthermore, such filters may calibrate the playback device or devices under calibration to one or more specific listening positions within the listening area. As mentioned above, the filter can be implemented in the DSP (eg, as the coefficients of a biquad filter) or as an analog filter or a combination thereof. The received calibration data may include filters for each audio channel, axis or device being calibrated. Alternatively, the filter may be applied to more than one audio channel, axis or device.

In some cases, multiple calibrations may correspond to respective playback configurations. As mentioned above, a playback configuration refers to a specific set of sound axes formed by multiple audio drivers. Additionally, example spatial calibration may include calibration of audio drivers in multiple playback configurations. Thus, for each audio channel, axis or device, there may be more than one filter (or set of filters). Each filter (or set of filters) may correspond to a different playback configuration.

As mentioned above, playback configurations may involve changes in the assignment of audio drivers used to form the sound axis. Each sound axis in the playback configuration may correspond to a corresponding input channel of audio content. Example playback configurations may correspond to different numbers of input channels, such as mono, stereo, surround (eg, 3.0, 5.0, 7.0), or any of the above combined with a subwoofer (eg, 3.1, 5.1, 7.1 ). Other playback configurations can be based on input content type. For example, an example playback configuration may correspond to input audio content including music, home theater (ie, audio paired with video), surround sound audio content, spoken language, and the like. These example playback configurations should not be considered limiting. The received calibration may include one or more filters corresponding to any individual playback configuration or any combination of playback configurations.

The playback device can maintain these calibrations in data storage. Alternatively, such calibration may be maintained on a device or system communicatively coupled to the playback device via a network. The playback device may receive calibrations from the device or system, possibly upon request from the playback device.

b. Make one or more audio drivers output calibrated audio

In Figure 19, at block 1904, implementation 1900 involves causing one or more audio drivers to output calibration audio. For example, a playback device may have the audio stage drive an audio driver to output calibrated audio. An example audio stage may include one or more amplifiers, signal processing (eg, DSP), and possibly other components. In some cases, a playback device may instruct other playback devices under calibration to output calibration audio, possibly when acting as a group coordinator for the playback devices under calibration.

Calibration audio may include one or more calibration sounds, such as frequency sweeps ("chirps"), brown noise or other types of noise or songs, among other examples. Additional details regarding example calibration sounds are indicated above in connection with the example calibration sequences described above.

Calibration audio can be divided into frames. As shown in FIGS. 11 and 12 and described herein, a frame may represent an iteration of an example calibration sound. When recorded, the frames may produce corresponding samples of calibration sounds as emitted by one or more audio drivers. Frames can be repeated to produce multiple samples.

As mentioned above, the calibration sequence may involve calibration of multiple acoustic axes. In such a case, the calibration audio output may be divided into constituent frames, where each frame includes calibration audio for each acoustic axis being calibrated. Thus, when recorded, each frame may include a sample of calibration audio produced by each acoustic axis. The frame can be repeated to produce multiple samples for each acoustic axis.

As described above, in some example calibration procedures, playback devices of a media playback system may be calibrated for multiple playback configurations. Alternatively, different playback configurations of the set of audio drivers may be calibrated in corresponding calibration sequences. Example calibration audio for calibrating multiple playback configurations may include repeated sets of frames. Each frame in the set may correspond to a corresponding playback configuration. For example, an example calibration audio for calibrating three playback configurations may include a series of three frames (eg, frames 1402, 1404, and 1406 of Figure 14).

During each frame, the playback device may apply a spatial calibration corresponding to the respective playback configuration. Applying spatial calibration may involve causing the audio level (or levels) to apply one or more respective filters corresponding to each playback configuration. When the input signal passes through the one or more filters, calibration is applied to modify one or more of the amplitude response, frequency response, phase adjustment, or any other acoustic characteristic of the one or more audio drivers when the calibration audio is emitted. As mentioned above, such filters can modify the emitted calibration audio to suit a particular listening position. For example, an example spatial filter may at least partially balance the arrival times of sounds from multiple acoustic axes at a particular listening position.

In other embodiments, the spatial calibration may be applied to calibrate the audio by a device other than the playback device. Spatial calibration can be applied by any device that stores calibration audio and/or uses the device's processor or DSP to generate calibration audio for output by an audio driver. Furthermore, spatial calibration may be applied by any intermediary device between the device storing the calibration audio and the playback device or devices being calibrated.

Each frame may be further divided into time slots in order to include calibration audio for each acoustic axis being calibrated. Each time slot may include calibration audio for the corresponding acoustic axis being calibrated. For example, an example frame of a playbar-type playback device (eg, playback device 104 shown in FIG. 1 ) forming three acoustic axes, such as left, right, and center channels, may include three time slots. For example, if a subwoofer-type device is to be used to calibrate the device, each frame may include four time slots, one for each acoustic axis formed by the playbar-type playback device, and one for each sound axis produced by the subwoofer sound axis. As another example, where a playbar-type playback device is calibrated with two additional playback devices producing corresponding acoustic axes (eg, surround left and surround right channels), each frame may include five time slots (or six time slots if calibrated with a subwoofer). Figure 14 shows an example calibration audio with constituent frames divided into time slots.

As described above, each time slot may include calibration audio for the corresponding acoustic axis that is being calibrated. Calibration tones in each time slot may include frequency sweeps ("chirps"), brown noise, or other types of noise, among other examples. For example, as shown in Figures 11 and 12, the calibration audio in each sound may include a mix of calibration sounds. The time slots may occur sequentially in a known order to facilitate matching the time slots within the recorded calibration audio to the corresponding acoustic axes. Each time slot may have a known duration, which may also facilitate matching the time slots within the recorded calibration audio to the corresponding acoustic axis. In other examples, each time slot and/or frame may include a watermark (eg, a specific sound pattern) for identifying the time slot or frame, which watermark may be used to match time slots within the recorded calibration audio to corresponding sound axis.

c. Receive data representing one or more spectral calibrations

In FIG. 19, at block 1906, implementation 1900 involves receiving data representing an or spectral calibration. For example, the playback device may receive data representing one or more spectral calibrations from the processing device. These spectral calibrations may be based on calibration audio output by one or more audio drivers. In particular, calibration audio output from one or more audio drivers may be recorded by one or more recording devices (eg, NMDs). Before being recorded, the calibration audio may be interacted with (eg, reflected or absorbed) by the surrounding environment and thus may characterize the environment.

An example spectral calibration can compensate for the acoustic properties of the environment to achieve a given response (eg, a flat response, considered a desired response, or set equalization). For example, if a given environment attenuates frequencies around 500Hz and amplifies frequencies around 14000Hz, calibration may boost frequencies around 500Hz and attenuate frequencies around 14000Hz to compensate for these environmental effects.

Some example techniques for determining calibration are described in US Patent Application No. 13/536,493, filed June 28, 2012, entitled "System and Method for Device Playback Calibration" and published as US 2014/0003625 A1, the entire contents of which are incorporated herein by reference in the text. Example techniques are described in paragraphs [0019] to [0025] and [0068] to [0118] and generally throughout the specification.

Other example techniques for determining calibration are described in US Patent Application No. 14/216,306, filed March 17, 2014, entitled "Audio SettingsBased On Environment" and published as US 2015/0263692A1, the entire contents of which are incorporated herein middle. Example techniques are described in paragraphs [0014] through [0025] and [0063] through [0114] and generally throughout the specification.

Additional example techniques for determining calibration are described in US Patent Application Serial No. 14/481,511, filed September 9, 2014, entitled "Playback DeviceCalibration" and published as US 2016/0014534A1, the entire contents of which are incorporated herein . Example techniques are described in paragraphs [0017] to [0043] and [0082] to [0184] and generally throughout the specification.

Example processing devices include NMDs, other playback devices, control devices, computing devices connected to the media playback system via a local area network, remote computing devices such as cloud servers, or any combination of the above. In some cases, the one or more processing devices may send the spatial calibration to one or more intermediate devices, which may send the spatial calibration to the playback device. Such an intermediate device may store data representing one or a spatial calibration.

d. Apply a specific spectral filter

At block 1908, implementing 1900 involves applying a specific spectral calibration. For example, when playing back audio content in a given playback configuration, the playback device may apply specific filters corresponding to the given playback configuration. The playback device can maintain or have access to corresponding spectral calibrations corresponding to multiple playback configurations.

In some examples, the playback device may be instructed to enter a particular playback configuration and apply a particular calibration corresponding to that playback configuration accordingly. For example, the control device may send commands to form a particular set of sound axes corresponding to a given playback configuration.

Alternatively, the playback device may detect the appropriate spectral calibration to apply based on its current configuration. As mentioned above, playback devices may be incorporated into various groupings such as zones or bound zones. Each grouping can represent a playback configuration. In some implementations, when incorporated into a group with additional playback devices, the playback device may apply specific calibrations associated with the group's playback configuration. For example, based on detecting that the playback device has been coupled to a particular zone, the playback device may apply a particular calibration associated with the zone (or with the particular zone).

The playback device may detect the spectral calibration to apply based on the audio content provided to the playback device (or having been instructed to play back). For example, a playback device may detect that it is playing back media content (eg, music) that consists only of audio. In this case, the playback device may apply a specific calibration associated with the playback configuration corresponding to the music playback. As another example, a playback device may receive media content (eg, television shows or movies) associated with both audio and video. When playing back such content, the playback device may apply a specific calibration corresponding to the audio paired with the video, or possibly a calibration corresponding to a home theater (eg, surround sound).

The playback device may apply specific calibrations based on the source of the audio content. Receiving content via specific ones of these sources can trigger specific playback configurations. For example, receiving content via a network interface may indicate music playback. In this way, when receiving content via the network interface, the playback device may apply specific calibrations associated with the specific playback configuration corresponding to music playback. As another example, receiving content via a specific physical input may indicate home theater usage (ie, playback of audio from a television show or movie). When playing back content from this input, the playback device may apply different calibrations associated with the playback configuration corresponding to home theater playback.

A given zone scene can be associated with a specific playback configuration. Upon entering a particular zone scene and thus entering a particular playback configuration, the playback device may apply a particular calibration associated with that playback configuration. Alternatively, the content or configuration associated with the zone scene may cause the playback device to apply specific calibrations. For example, a zone scene may involve playback of a particular media content or content source, which causes the playback device to apply a particular calibration.

In further examples, the playback configuration may be indicated to the playback device via one or more messages from the control device or another playback device. For example, upon receiving input to select a particular playback configuration, the device may indicate to the playback device that the particular playback configuration was selected. The playback device may apply the calibration associated with the playback configuration. As another example, a playback device may be a member of a group such as a binding zone group. Another playback device, such as the group coordinator device for the group, may detect the playback configuration of the group and send a message to the playback device indicating the playback configuration (or calibration for that configuration).

In some cases, the playback device may also apply the calibration to one or more additional playback devices. For example, a playback device may be a member (eg, a group coordinator) of a group (eg, a zone group). The playback device may send a message instructing the other playback devices in the group to apply the calibration. Upon receipt of such a message, these playback devices may apply calibration.

In some examples, the calibration or calibration state may be shared among devices of the media playback system using one or more state variables. Some example techniques involving calibration state variables are in US Patent Application Serial No. 14/793,190, filed July 7, 2015, entitled "Calibration State Variable," and US Patent Application No. 14/793,190, filed July 7, 2015, and entitled "Calibration Indicator" described in Patent Application No. 14/793,205, the entire contents of which are incorporated herein. V. Example Techniques for Facilitating Spectral Calibration Using Applied Spatial Calibration

As described above, embodiments described herein may facilitate calibration of one or more playback devices. FIG. 20 illustrates an example implementation 200 by which the NMD uses the applied spatial calibration to facilitate spectral calibration of a media playback system.

a. Detect trigger conditions

At block 2002, implementation 2000 involves detecting a triggering condition to initiate calibration. For example, the NMD may detect a trigger condition that initiates calibration of the media playback system. A trigger condition may initiate calibration of one or more playback devices in a media playback system for multiple playback configurations, either explicitly or possibly because one or more audio drivers of the one or more playback devices have been set up with multiple playback configurations . Example trigger conditions for initiating calibration are described in Section III.a above and generally throughout this disclosure.

b. Make one or more audio drivers output calibrated audio

In Figure 20, at block 2004, implementation 2000 involves causing one or more audio drivers to output calibration audio. For example, an NMD can have multiple audio drivers output calibrated audio. The NMD may send instructions to the calibrated playback device via a network interface. Example calibration audio is described above in connection with example calibration techniques.

c. Record calibration audio

In Figure 20, at block 2006, implementation 2000 involves recording calibration audio. For example, the NMD may record, via a microphone, calibration audio as output by one or more audio drivers of the one or more playback devices being calibrated. In some cases, multiple NMDs may record calibration audio via respective microphones.

The NMD can move within the environment while recording the calibration audio to measure the calibration sound at different locations. Using a moving microphone, the repetition of the calibration sound is detected at different physical locations within the environment. Samples of the calibration sound at different locations may provide a better representation of the surrounding environment than samples in one location. For example, referring back to FIG. 7 , the control device 126 of the media playback system 100 may detect at various points along the path 700 (eg, at points 702 and/or 704 ) detection by one or more playback devices (eg, a living room) calibration audio from playback devices 104, 106, 108 and/or 110) in the zone. Alternatively, the control device may record calibration signals along this path.

In this way, the NMD can display one or more prompts to move the NMD while the calibration audio is being issued. Such prompts may guide the user to move the recording device during calibration. For illustration, in FIG. 21 , smartphone 500 is displaying control interface 2100 including graphics areas 2102 and 2104 . Graphics area 2102 prompts viewing of animations in graphics area 2104. Such an animation may depict an example of how to move the smartphone within the environment during calibration to measure calibration audio at different locations. Although an animation is shown in graphics area 2104 by way of example, the control device may alternatively show video or other instructions illustrating how to move the control device within the environment during calibration. Control interface 2100 also includes selectable controls 2106 and 2108, which advance and reverse, respectively, in the calibration sequence.

Other examples for recording calibration audio are described in Section III.a above and generally throughout this disclosure.

d. Determine one or more spectral calibrations

At block 2008, implementation 2000 involves determining a spectral calibration. For example, the NMD may cause the processing device to determine respective sets of spectral filters for the multiple playback configurations that are being calibrated. These spectral calibrations may be based on recorded calibration audio output by one or more audio drivers. In some cases, the NMD may include processing equipment. Alternatively, the NMD may send the recorded audio to one or more other processing devices. Example processing devices and processing techniques are described above.

When a media playback system plays back audio content in a given playback configuration, the NMD may apply a specific calibration (eg, a specific set of spectral filters) corresponding to the given playback configuration to the sound axis formed by the plurality of audio drivers. Further examples of applying calibration are described above.

VI. Conclusion

The above description discloses, among other things, various example systems, methods, apparatus, and articles of manufacture including firmware and/or software executing on hardware and other components. It should be understood that such examples are merely illustrative and should not be considered limiting. For example, it is contemplated that any or all of the firmware, hardware and/or software aspects or components may be implemented exclusively in hardware, exclusively in software, exclusively in firmware or in any combination of hardware, software and/or firmware. Accordingly, the examples provided are not the only way to implement such systems, methods, apparatus and/or articles of manufacture.

(Feature 1) A method comprising: detecting a trigger condition that initiates calibration of a media playback system including a plurality of audio drivers forming a plurality of sound axes, each sound axis corresponding to a plurality of sound channel audio content; causing the plurality of audio drivers to emit framed calibration audio via a network interface, the plurality of sound axes emitting calibration audio during respective time slots of each frame; via microphones recording the emitted calibration audio; causing a respective delay for each of the plurality of acoustic axes to be determined based on time slots of the recorded calibration audio corresponding to the acoustic axes; and causing the plurality of acoustic axes to be calibrated , wherein calibrating the plurality of acoustic axes includes causing the audio output of the plurality of acoustic axes to be delayed according to correspondingly determined delays.

(Feature 2) The method of feature 1, wherein causing the determination of the respective delay for each of the plurality of acoustic axes comprises causing the processing device to calibrate the timing of the audio according to the recording corresponding to each acoustic axis gaps to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes; and such that a delay for each of the plurality of acoustic axes is determined, each determined delay corresponding to The determined arrival time at the corresponding acoustic axis.

(Feature 3) The method of feature 2, wherein causing the audio output of the plurality of sound axes to be delayed according to the respective determined delays comprises causing respective filters to delay the audio output according to the respective determined delays of the plurality of sound axes delaying audio output of the plurality of audio drivers.

(Feature 4) The method of feature 2, wherein the NMD includes the processing device, and wherein the processing device is caused to determine a corresponding response at the microphone for each of the plurality of acoustic axes The time of arrival includes dividing the recorded calibration audio into constituent frames and dividing each constituent frame into a corresponding time slot for each acoustic axis; determining the acoustic axis from the respective time slot corresponding to each acoustic axis aligning the corresponding impulse responses to the first reference point; identifying the corresponding second reference point in each impulse response; and based on the first reference point and the second reference point in each impulse response The corresponding difference of the points determines the corresponding arrival time at the microphone.

(Feature 5) The method of feature 4, wherein the acoustic axis consists of a reference acoustic axis and one or more other acoustic axes, and wherein identifying the corresponding second reference point in each impulse response comprises: identifying a peak in the impulse response of the reference acoustic axis as a given second reference point; and identifying the one or more other acoustic axes in a time window following the given second reference point The corresponding peaks of the impulse responses serve as other second reference points.

(Feature 6) The method of feature 2, wherein the processing device is connected to the NMD via one or more networks, and wherein the processing device is caused to determine each acoustic axis of the plurality of acoustic axes The respective arrival times at the microphones include sending (i) the recorded calibration audio to the processing device via the network interface, and (ii) determining the an instruction of a corresponding time of arrival at the microphone; and receiving the determined corresponding time of arrival via the network interface.

(Feature 7) The method of feature 1, wherein each acoustic axis of the plurality of acoustic axes corresponds to a corresponding channel of surround sound audio content.

(Feature 8) The method of feature 7, wherein the media playback system includes a plurality of playback devices, each playback device including a subset of the plurality of audio drivers.

(Feature 9) The method of feature 8, wherein the plurality of playback devices comprises a given playback device comprising a specific subset of the plurality of audio drivers, wherein the plurality of A particular subset of audio drivers form three sound axes corresponding to the left channel of the surround audio content, the right channel of the surround audio content, and the center sound of the audio content, respectively. road.

(Feature 10) The method of feature 1, wherein detecting the trigger condition to initiate calibration of the media playback system comprises: detecting, via a user interface, input data indicating initiation of calibration of the media playback system Calibration command.

(Feature 11) The method according to feature 1, wherein detecting the trigger condition that initiates calibration of the media playback system comprises detecting that the configuration of the media playback system is a specific axis configuration, wherein the plurality of Audio drivers form a specific set of sound axes.

(Feature 12) The method of feature 1, wherein causing the delay of each of the plurality of sound axes to be determined comprises: determining that the arrival time of a given sound axis exceeds a maximum delay threshold; and when the media The playback system is playing back audio content paired with video content such that the delay for the given sound axis is set at the maximum delay threshold.

(Feature 13) A tangible non-transitory computer-readable medium storing instructions executable by one or more processors to cause an apparatus to perform the method according to any one of features 1 to 12 .

(Feature 14) An apparatus configured to perform the method according to any one of features 1 to 12.

(Feature 15) A media playback system configured to perform the method according to any one of features 1 to 12.

(Feature 16) A method comprising: receiving, via a network interface, data representing one or more spatial filters corresponding to respective respective playback configurations, wherein each playback configuration representation is formed via one or more audio drivers and wherein each sound axis corresponds to a corresponding channel of audio content; causing the one or more audio drivers to output calibration audio via an audio stage, the calibration audio being divided into a repeating set of frames , the set of frames includes respective frames for each playback configuration, wherein causing the one or more audio drivers to output calibration audio includes causing the audio stage to apply a corresponding frame to the respective playback configuration during each frame a spatial filter; receiving, via the network interface, data representing one or more spectral filters corresponding to respective playback configurations, the one or more spectral filters based on data generated by the one or more audio drivers output calibration audio; and causing the audio stage to apply a specific spectral filter corresponding to the given playback configuration when the audio content is played back in the given playback configuration.

(Feature 17) The method of feature 16, wherein receiving data representing one or more spatial filters comprises receiving data representing calibration of the playback device to a particular listening position within a listening area of the playback device data for one or more spatial filters, and wherein receiving data representing one or more spectral filters includes receiving data representing one or more spectral filters that compensate for acoustic properties of the listening area data.

(Feature 18) The method of feature 16, wherein receiving data representing one or more spatial filters comprises receiving data representing one or more sets of spatial filters, each set of spatial filters comprising a respective spatial filter for each acoustic axis, and wherein receiving data representing one or more spectral filters comprises receiving data representing one or more sets of spectral filters, each spectral filter comprising Corresponding spectral filters for each acoustic axis.

(Feature 19) The method of feature 18, wherein the one or more spatial filters include at least one of: (i) a first filter corresponding to a mono playback configuration, where when the audio content is played back in the mono playback configuration, the one or more audio drivers are configured to form a sound axis to output the mono audio content, (ii) a second filter corresponding to the stereo playback configuration, When the audio content is played back in the stereo playback configuration, the one or more audio drivers are configured to form one or more sound axes to output one or more channels of the stereo audio content, and (iii) a third filter corresponding to a surround sound playback configuration in which the one or more audio drivers are configured to form one or more sound axes to output surround sound audio when the audio content is played back in the surround sound playback configuration One or more channels of content.

(Feature 20) The method of feature 18, wherein the mono playback configuration is a first mono playback configuration, the stereo playback configuration is a first stereo playback configuration, and the surround playback configuration is a first surround sound configuration, and wherein the one or more spatial filters include at least one of: (i) a fourth filter corresponding to the second mono playback configuration, in the When the second mono playback configuration plays back the audio content, the one or more audio drivers are configured to form an acoustic axis to output the mono audio content in synchronization with the subwoofer device, (ii) corresponding to the second a fifth filter of a stereo playback configuration, the one or more audio drivers are configured to form one or more acoustic axes to interact with the subwoofer when the audio content is played back in the second stereo playback configuration The speaker device synchronously outputs one or more channels of stereo audio content, and (iii) a sixth filter corresponding to a second surround playback configuration in which the audio content is played back, The one or more audio drivers are configured to form one or more sound axes to output one or more channels of surround sound audio content in synchronization with the subwoofer device.

(Feature 21) The method of feature 16, wherein the one or more spatial filters comprise: (i) a first filter corresponding to a music playback configuration in which the audio content is played back , the one or more audio drivers are configured to form one or more sound axes to output music content, and (ii) a second filter corresponding to a home theater playback configuration in which playback is performed at the home theater When configured to play back the audio content, the one or more audio drivers are configured to form one or more sound axes to output the audio content paired with the video content.

(Feature 22) The method of feature 16, wherein the one or more audio drivers include a plurality of audio drivers forming a plurality of sound axes in a given playback configuration, and wherein the one or more audio drivers are caused to Outputting the calibration audio by the plurality of audio drivers includes causing the plurality of sound axes to output the calibration audio during respective time slots of each frame corresponding to the given playback configuration.

(Feature 23) The method of feature 22, wherein each sound axis of the plurality of sound axes corresponds to a respective channel of surround sound audio content.

(Feature 24) The method of feature 22, wherein each acoustic axis of the plurality of acoustic axes corresponds to a respective channel of stereo audio content.

(Feature 25) The method of feature 16, wherein the one or more audio drivers form a single sound axis in a given playback configuration.

(Feature 26) A tangible non-transitory computer-readable medium storing instructions executable by one or more processors to cause an apparatus to perform the method according to any one of features 16 to 25 .

(Feature 27) An apparatus configured to perform the method according to any one of features 16 to 25.

(Feature 28) A media playback system configured to perform the method according to any one of features 16 to 25.

(Feature 29) A method comprising: detecting a trigger condition that initiates calibration of a media playback system for a plurality of playback configurations, wherein each playback configuration represents a formation via a plurality of audio drivers of the media playback system and wherein each sound axis corresponds to a corresponding channel of audio content; causing the plurality of audio drivers to output calibration audio via a network interface, the calibration audio being divided into a repeating set of frames, the The set of frames includes respective frames configured for each playback, wherein causing the plurality of audio drivers to output the calibration audio includes causing a respective set of spatial filters to be applied to the plurality of frames during each frame of the set of frames. audio drivers, each set of spatial filters including a corresponding spatial filter for each acoustic axis; recording the calibration audio output by the plurality of audio drivers via a microphone; causing the processing device to generate the calibration audio based on the recorded calibration audio Respective sets of spectral filters are determined for the plurality of playback configurations, each set of spectral filters including a corresponding spectral filter for each acoustic axis.

(Feature 30) The method of feature 29, further comprising: when the media playback system plays back audio content in a given playback configuration, causing the specific spectral filter corresponding to the given playback configuration to be The set applies to the sound axis formed by the plurality of audio drivers.

(Feature 31) The method according to feature 29, wherein the calibration audio is a second calibration audio, the method further comprising: prior to causing the plurality of audio drivers to output the second calibration audio, via the The network interface causes the plurality of drivers to output a first calibration audio divided into a repeated set of frames, the set of frames including corresponding frames for each playback configuration of the plurality of playback configurations; recording via the microphone by the first calibration audio output by the plurality of audio drivers; and causing the processing device to determine the respective set of spatial filters for the plurality of playback configurations based on the recorded first calibration audio, each The set of spatial filters includes a corresponding spatial filter for each acoustic axis.

(Feature 32) The method of feature 29, wherein causing the plurality of audio drivers to output the calibration audio comprises causing the plurality of audio drivers to form the plurality of audio drivers during respective time slots of each frame the corresponding acoustic axis in the axis.

(Feature 33) The method of feature 29, wherein the plurality of playback configurations includes two or more of the following playback configurations: (i) a mono playback configuration in which playback in the mono When configured to play back audio content, the plurality of audio drivers are configured to form a sound axis to output mono audio content synchronously, (ii) a stereo playback configuration in which the plurality of audio drivers are configured to play back audio content in the stereo playback configuration; a plurality of audio drivers are configured to form a sound axis to output channels of stereo audio content, and (iii) a surround sound playback configuration in which the plurality of audio drivers are configured to form a surround sound playback configuration when the audio content is played back sound axis to output the corresponding channel of surround audio content.

(Feature 34) The method of feature 33, wherein the mono playback configuration is a first mono playback configuration, the stereo playback configuration is a first stereo playback configuration, and the surround playback configuration is A first surround sound configuration, wherein the plurality of playback configurations includes at least one of: (i) a second mono playback configuration in which, when the audio content is played back, the a plurality of audio drivers configured to form one or more full-range sound shafts and subwoofer sound shafts to output mono audio content in synchrony, (ii) a second stereo playback configuration, in which playback in said second stereo When configured to play back the audio content, the plurality of audio drivers are configured to form one or more full-range sound axes to output channels of the stereo content audio content in synchronization with the subwoofer sound axis, and (iii) a second a surround sound playback configuration wherein the plurality of audio drivers are configured to form one or more full-range sound axes for output in synchronization with the subwoofer sound axis when the audio content is played back in the second surround sound playback configuration The corresponding channel of the surround content audio content.

(Feature 35) The method of feature 29, wherein the plurality of playback configurations includes two or more of the following playback configurations: (i) a music playback configuration in which audio content is played back , the plurality of audio drivers are configured to form an acoustic axis to output music content, and (ii) a home theater playback configuration in which the plurality of audio drivers are configured to play back audio content in the home theater playback configuration A sound axis is formed to output audio content paired with video content.

(Feature 36) The method of feature 29, wherein causing the respective set of spatial filters to be applied to the plurality of audio drivers during each frame of the set of frames comprises causing the processing device to apply all The spatial filter is applied to the calibration audio, and the calibration audio to which the spatial filter is applied is sent to one or more playback devices including the plurality of audio drivers.

(Feature 37) The method of feature 29, wherein the media playback system includes a plurality of playback devices, each playback device including a subset of the plurality of audio drivers.

(Feature 38) A tangible non-transitory computer readable medium storing instructions executable by one or more processors to cause an apparatus to perform the method according to any one of features 29 to 37 .

(Feature 39) An apparatus configured to perform the method according to any one of features 29 to 37.

(Feature 40) A media playback system configured to perform the method according to any one of features 29 to 37.

(Feature 41) A playback device comprising: (i) a network interface; (ii) an audio stage arranged to drive one or more audio drivers; (iii) one or more processors; (iv) storage A computer-readable medium having instructions executable by the one or more processors to cause the playback device to perform operations comprising: (a) receiving a representation and a corresponding playback configuration via the network interface data for the corresponding one or more spatial filters, wherein each playback configuration represents a particular set of sound axes formed via the one or more audio drivers, and wherein each sound axis corresponds to a a corresponding channel; (b) causing the one or more audio drivers to output, via the audio stage, calibration audio divided into repeated sets of frames, the set of frames including corresponding frames configured for each playback, wherein all outputting the calibration audio by the one or more audio drivers includes causing the audio stage to apply the spatial filter corresponding to a respective playback configuration during each frame; (c) receiving via the network interface a representation with corresponding playback configuration data for one or more spectral filters corresponding to the one or more spectral filters based on the calibration audio output by the one or more audio drivers; and (d) in When the audio content is played back in a given playback configuration, the audio stage is caused to apply a specific spectral filter corresponding to the given playback configuration.

(Feature 42) The playback device of feature 41, wherein receiving data representing one or more spatial filters comprises receiving data representing calibration of the playback device to a particular listening position within a listening area of the playback device and wherein receiving data representing one or more spectral filters includes receiving data representing one or more spectral filters compensating for acoustic properties of the listening area The data.

(Feature 43) The playback device of feature 41, wherein receiving data representing one or more spatial filters comprises receiving data representing one or more sets of spatial filters, each set of spatial filters comprising respective spatial filters for each acoustic axis, and wherein receiving data representing one or more spectral filters comprises receiving data representing one or more sets of spectral filters, each spectral filter Corresponding spectral filters are included for each acoustic axis.

(Feature 44) The playback device of feature 41, wherein the one or more spatial filters include at least one of: (i) a first filter corresponding to a mono playback configuration, When the audio content is played back in the mono configuration, the one or more audio drivers are configured to form a sound axis to output the mono audio content, (ii) a second filter corresponding to the stereo playback configuration, When the audio content is played back in the stereo playback configuration, the one or more audio drivers are configured to form one or more sound axes to output one or more channels of the stereo audio content, and (iii) a third filter corresponding to a surround sound playback configuration in which the one or more audio drivers are configured to form one or more sound axes to output surround sound audio when the audio content is played back in the surround sound playback configuration One or more channels of content.

(Feature 45) The playback device according to feature 44, wherein the monaural playback configuration is a first mono playback configuration, the stereo playback configuration is a first stereo playback configuration, and the surround playback configuration is a first surround sound configuration, and wherein the one or more spatial filters include at least one of: (i) a fourth filter corresponding to the second mono playback configuration, where so When the second mono playback configuration plays back the audio content, the one or more audio drivers are configured to form an acoustic axis to output the mono audio content in synchronization with the subwoofer device, (ii) corresponding to the second a fifth filter of a stereo playback configuration, the one or more audio drivers are configured to form one or more acoustic axes to interact with the subwoofer when the audio content is played back in the second stereo playback configuration The device outputs one or more channels of stereo audio content synchronously, and (iii) a sixth filter corresponding to a second surround playback configuration in which the audio content is played back in the second surround playback configuration. The one or more audio drivers are configured to form one or more sound axes to output one or more channels of surround sound audio content in synchronization with the subwoofer device.

(Feature 46) The playback device of feature 41, wherein the one or more spatial filters include: (i) a first filter corresponding to a music playback configuration in which audio is played back content, the one or more audio drivers are configured to form one or more sound axes to output the music content, and (ii) a second filter corresponding to a home theater playback configuration in which the home theater When the playback configuration plays back the audio content, the one or more audio drivers are configured to form one or more sound axes to output the audio content paired with the video content.

(Feature 47) The playback device according to feature 41, wherein the one or more audio drivers include a plurality of audio drivers forming a plurality of sound axes in a given playback configuration, and wherein the one or more audio drivers are made Outputting the calibration audio by the plurality of audio drivers includes causing the plurality of sound axes to output the calibration audio during respective time slots of each frame corresponding to the given playback configuration.

(Feature 48) The playback device of feature 47, wherein each sound axis of the plurality of sound axes corresponds to a respective channel of surround sound audio content.

(Feature 49) The playback device of feature 47, wherein each sound axis of the plurality of sound axes corresponds to a respective channel of the stereo audio content.

(Feature 50) The playback device of feature 41, wherein the one or more audio drivers form a single sound axis in a given playback configuration.

(Feature 51) A tangible, non-transitory computer-readable medium storing instructions executable by one or more processors to cause a networked microphone device (NMD) to perform a method comprising: (i ) detects a trigger condition that initiates calibration of a media playback system for a plurality of playback configurations, wherein each playback configuration represents a particular set of sound axes formed via a plurality of audio drivers of the media playback system, and wherein, Each sound axis corresponds to a corresponding channel of audio content; (ii) causing the plurality of audio drivers to output, via a network interface, calibrated audio divided into repeated sets of frames, the sets of frames comprising corresponding frame, wherein causing the plurality of audio drivers to output the calibration audio includes causing a respective set of spatial filters to be applied to the plurality of audio drivers during each frame of the set of frames, each set of spatial filters including a corresponding spatial filter for each acoustic axis; (iii) recording, via the microphone, the calibration audio output by the plurality of audio drivers; (iv) causing the processing device to determine the use of the calibration audio based on the recorded calibration audio Respective sets of spectral filters in the plurality of playback configurations, each set of spectral filters including a corresponding spectral filter for each acoustic axis.

(Feature 52) The tangible, non-transitory computer-readable medium of feature 51, the method further comprising: when the media playback system plays back the audio content in a given playback configuration, causing the media playback system to play back the audio content with the given playback configuration A corresponding set of specific spectral filters is applied to the acoustic axis formed by the plurality of audio drivers.

(Feature 53) The tangible, non-transitory computer-readable medium of feature 51, wherein the calibration audio is a second calibration audio, the method further comprising: (i) causing the plurality of audio drivers to output all of the causing the plurality of drives to output a first calibration audio via the network interface prior to the second calibration audio, the first calibration audio being divided into a repeating set of frames, the set of frames including a configuration for the plurality of playback (ii) recording, via the microphone, the first calibration audio output by the plurality of audio drivers; and (iii) causing the processing device to base the recorded first calibration on audio to determine respective sets of spatial filters for the plurality of playback configurations, each set of spatial filters including respective spatial filters for each acoustic axis.

(Feature 54) The tangible, non-transitory computer-readable medium of feature 51, wherein causing the plurality of audio drivers to output the calibration audio comprises causing the plurality of audio drivers to output the calibration audio at corresponding time slots of each frame Corresponding acoustic axes of the plurality of acoustic axes are formed during the process.

(Feature 55) The tangible, non-transitory computer-readable medium of feature 51, wherein the plurality of playback configurations includes two or more of the following playback configurations: (i) a mono playback configuration, where When the audio content is played back in the mono playback configuration, the plurality of audio drivers are configured to form a sound axis to output the mono audio content synchronously, (ii) a stereo playback configuration, in which playback in the stereo playback configuration When playing back audio content, the plurality of audio drivers are configured to form a sound axis to output channels of stereo audio content, and (iii) a surround sound playback configuration in which when the audio content is played back in the surround sound playback configuration, the plurality of audio drivers are The audio drivers are configured to form a sound axis to output respective channels of surround sound audio content.

(Feature 56) The tangible, non-transitory computer-readable medium of feature 55, wherein the mono playback configuration is a first mono playback configuration, the stereo playback configuration is a first stereo playback configuration, and The surround sound playback configuration is a first surround sound configuration, wherein the plurality of playback configurations includes at least one of the following playback configurations: (i) a second mono playback configuration in which the mono playback configuration is When playing back the audio content, the plurality of audio drivers are configured to form one or more full-range sound shafts and subwoofer sound shafts to output mono audio content synchronously, (ii) a second stereo playback configuration, When the audio content is played back in the second stereo playback configuration, the plurality of audio drivers are configured to form one or more full-range sound axes to output sound of the stereo content audio content in synchronization with the subwoofer sound axis channel, and (iii) a second surround sound playback configuration in which the plurality of audio drivers are configured to form one or more full-range sound axes to interact with the audio content when playing back audio content in the second surround sound playback configuration. The subwoofer sound axis outputs the corresponding channels of surround content audio content synchronously.

(Feature 57) The tangible, non-transitory computer-readable medium of feature 51, wherein the plurality of playback configurations includes two or more of the following playback configurations: (i) a music playback configuration in which The plurality of audio drivers are configured to form an acoustic axis to output the music content when the audio content is played back in the music playback configuration, and (ii) a home theater playback configuration in which the audio content is played back in the home theater playback configuration. A plurality of audio drivers are configured to form a sound axis to output audio content paired with video content.

(Feature 58) The tangible, non-transitory computer-readable medium of feature 51, wherein causing the respective set of spatial filters to be applied to the plurality of audio drivers during each frame of the set of frames comprises: The processing device is caused to apply the spatial filter to the calibration audio, and send the spatial filter-applied calibration audio to one or more playback devices including the plurality of audio drivers.

(Feature 59) The tangible, non-transitory computer-readable medium of feature 51, wherein the media playback system includes a plurality of playback devices, each playback device including a subset of the plurality of audio drivers.

(Feature 60) A media playback system comprising: (i) one or more playback devices including a plurality of audio drivers forming a plurality of sound axes, each sound axis corresponding to a corresponding channel of audio content; (ii) ) a networked microphone device, including a microphone; (iii) a processor; and (iv) a computer-readable medium having stored instructions executable by one or more processors to cause the media playback system to perform including the following Method of operation: (a) detecting a trigger condition that initiates calibration of the media playback system for a plurality of playback configurations, wherein each playback configuration represents a particular set of sound axes formed via the plurality of audio drivers (b) causing the plurality of audio drivers to output calibration audio via a network interface, the calibration audio being divided into a repeating set of frames, the set of frames comprising corresponding frames configured for each playback, wherein the plurality of audio drivers are caused to outputting the calibration audio by a plurality of audio drivers includes causing a corresponding set of spatial filters to be applied to the plurality of audio drivers during each frame of the set of frames, each set of spatial filters including a set of spatial filters for each acoustic axis a corresponding spatial filter; (c) recording the calibration audio output by the plurality of audio drivers via the microphone; (d) causing a processing device to determine a calibration audio for the plurality of playback configurations based on the recorded calibration audio Corresponding spectral filter sets, each spectral filter set including a corresponding spectral filter for each acoustic axis.

(Feature 61) A tangible, non-transitory computer-readable medium storing instructions executable by one or more processors to cause a networked microphone device (NMD) to perform a method comprising: (i ) detecting a trigger condition that initiates calibration of a media playback system comprising a plurality of audio drivers forming a plurality of acoustic axes, each acoustic axis corresponding to a corresponding channel of the multi-channel audio content; ( ii) causing the plurality of audio drivers to emit calibration audio via a network interface, the calibration audio being divided into constituent frames, the plurality of acoustic axes emitting calibration audio during respective time slots of each constituent frame; (iii) via recording the emitted calibration audio by a microphone; (iv) causing a respective delay for each of the plurality of acoustic axes to be determined based on time slots of the recorded calibration audio corresponding to the acoustic axes; and (v) causing the plurality of acoustic axes to be calibrated, wherein calibrating the plurality of acoustic axes includes causing audio output of the plurality of acoustic axes to be delayed according to respective determined delays.

(Feature 62) The tangible, non-transitory computer-readable medium of feature 61, wherein causing the determination of the respective delay for each of the plurality of acoustic axes comprises: (i) causing the processing device to be time slots of the recorded calibration audio corresponding to the acoustic axes to determine the respective arrival times at the microphones for each of the plurality of acoustic axes; and (ii) causing the determination of the The delay of each acoustic axis of , each determined delay corresponds to the determined arrival time of the corresponding acoustic axis.

(Feature 63) The tangible, non-transitory computer-readable medium of feature 62, wherein causing the audio output of the plurality of sound axes to be delayed according to the respective determined delays comprises causing respective filters to delay the audio output according to the plurality of sound axes A corresponding determined delay of the axes delays the audio output of the plurality of audio drivers.

(Feature 64) The tangible, non-transitory computer-readable medium of feature 62, wherein the NMD includes the processing device, and wherein the processing device is caused to determine each acoustic axis of the plurality of acoustic axes The respective arrival times of the axes at the microphones include: (i) dividing the recorded calibration audio into the constituent frames and dividing each constituent frame into a respective time slot for each acoustic axis; (ii) ) determining the respective impulse responses of the acoustic axes according to the respective time slots corresponding to the acoustic axes; (iii) aligning the respective impulse responses to a first reference point; (iv) identifying the respective impulse responses in each impulse response and (v) determining a respective time of arrival at the microphone based on the respective difference between the first reference point and the second reference point in each impulse response.

(Feature 65) The tangible, non-transitory computer-readable medium of feature 64, wherein the acoustic axis consists of a reference acoustic axis and one or more other acoustic axes, and wherein the acoustic axis in each impulse response is identified A corresponding second reference point includes: (i) identifying a peak in the impulse response of the reference acoustic axis as a given second reference point; and (ii) in a time window following the given second reference point , the corresponding peaks of the impulse responses of the one or more other acoustic axes are identified as other second reference points.

(Feature 66) The tangible, non-transitory computer-readable medium of feature 62, wherein the processing device is connected to the NMD via one or more networks, and wherein the processing device is caused to determine the plurality of The respective time of arrival at the microphone for each of the acoustic axes comprises: (i) sending (a) the recorded calibration audio to the processing device via the network interface and (b) determining the an instruction of a respective time of arrival at the microphone for each of the plurality of acoustic axes; and (ii) receiving the determined respective time of arrival via the network interface.

(Feature 67) The tangible, non-transitory computer-readable medium of feature 61, wherein each acoustic axis of the plurality of acoustic axes corresponds to a respective channel of surround sound audio content.

(Feature 68) The tangible, non-transitory computer-readable medium of feature 67, wherein the media playback system includes a plurality of playback devices, each playback device including a subset of the plurality of audio drivers.

(Feature 69) The tangible, non-transitory computer-readable medium of feature 68, wherein the plurality of playback devices comprises a given playback device comprising a particular subset of the plurality of audio drivers , wherein a particular subset of the plurality of audio drivers forms three sound axes corresponding to the left channel of the surround audio content, the right channel of the surround audio content, and The center channel of the audio content.

(Feature 70) The tangible, non-transitory computer-readable medium of feature 61, wherein detecting the trigger condition to initiate calibration of the media playback system comprises detecting, via a user interface, input data indicating initiation of Commands for calibration of the media playback system.

(Feature 71) The tangible, non-transitory computer-readable medium of feature 61, wherein detecting the trigger condition that initiates calibration of a media playback system comprises detecting that the configuration of the media playback system is a particular axis configuration, wherein , the plurality of audio drivers form a specific set of sound axes.

(Feature 72) The tangible, non-transitory computer-readable medium of feature 61, wherein causing the determination of a delay for each of the plurality of acoustic axes comprises: (i) determining a time of arrival for a given acoustic axis exceeding a maximum delay threshold; and (ii) causing the delay for the given sound axis to be set at the maximum delay threshold when the media playback system is playing back audio content paired with video content.

(Feature 73) A method comprising: (i) detecting a trigger condition that initiates calibration of a media playback system comprising a plurality of audio drivers forming a plurality of sound axes, each sound axis corresponding to corresponding channels of the multi-channel audio content; (ii) causing the plurality of audio drivers to emit calibration audio via a network interface, the calibration audio being divided into constituent frames, the plurality of sound axes at the end of each constituent frame emit calibration audio during the corresponding time slot; (iii) record the emitted calibration audio via the microphone of the Networked Microphone Device (NMD); (iv) cause the processing device to generate a calibration audio according to the time slot corresponding to the sound axis of the recorded calibration audio determining a respective arrival time at the microphone for each of the plurality of acoustic axes; (v) such that a delay for each of the plurality of acoustic axes is determined, each determined delay corresponding to and (vi) causing calibration of the plurality of acoustic axes, wherein calibrating the plurality of acoustic axes includes causing delays of the plurality of acoustic axes according to the respective determined delays Audio output.

(Feature 74) The method of feature 73, wherein the NMD includes the processing device, and wherein the processing device is caused to determine at the microphone of each of the plurality of acoustic axes The respective arrival times of the include: (i) dividing the recorded calibration audio into the constituent frames and dividing each constituent frame into a corresponding time slot for each acoustic axis; (ii) dividing the recorded calibration audio into the constituent frames; (iii) aligning the respective impulse responses to the first reference point; (iv) identifying the respective second reference point in each impulse response; and ( v) Determining a respective time of arrival at the microphone based on the respective difference between the first reference point and the second reference point in each impulse response.

(Feature 75) The method of feature 74, wherein the acoustic axis consists of a reference acoustic axis and one or more other acoustic axes, and wherein identifying a corresponding second reference point in each impulse response comprises: (i) identifying a peak in the impulse response of the reference acoustic axis as a given second reference point; and (ii) in a time window following the given second reference point, identifying the one or more Corresponding peaks of the impulse responses of a plurality of other acoustic axes serve as other second reference points.

(Feature 76) The method of feature 73, wherein the processing device is connected to the NMD via one or more networks, and wherein the processing device is caused to determine each of the plurality of acoustic axes The respective arrival times of the acoustic axes at the microphones include: (i) sending (a) the recorded calibration audio to the processing device via the network interface, and (b) determining the number of acoustic axes in the plurality of acoustic axes. an instruction of a respective time of arrival at the microphone for each acoustic axis; and (ii) receiving the determined respective time of arrival via the network interface.

(Feature 77) The method of feature 73, wherein each sound axis of the plurality of sound axes corresponds to a respective channel of surround sound audio content, and wherein the media playback system includes a plurality of playback devices , each playback device includes a subset of the plurality of audio drivers.

(Feature 78) The method of feature 77, wherein the plurality of playback devices comprises a given playback device comprising a particular subset of the plurality of audio drivers, wherein the plurality of A particular subset of audio drivers form three sound axes corresponding to the left channel of the surround audio content, the right channel of the surround audio content, and the center sound of the audio content, respectively. road.

(Feature 79) The method of feature 73, wherein detecting the triggering condition to initiate calibration of the media playback system comprises one of: (a) detecting, via a user interface, input data indicative of initiation A command for calibration of the media playback system, or (b) detecting that the configuration of the media playback system is a particular axis configuration, wherein the plurality of audio drivers form a particular set of acoustic axes.

(Feature 80) A media playback system comprising: (i) one or more playback devices including a plurality of audio drivers forming a plurality of sound axes, each sound axis corresponding to a corresponding channel of multi-channel audio content (ii) a networked microphone device, including a microphone; (iii) a processor; and (iv) a computer-readable medium having stored instructions executable by one or more processors to cause the media playback system to perform including A method of operating the following: (a) detecting a trigger condition that initiates calibration of a media playback system, causing the plurality of audio drivers to emit calibration audio via a network interface, the calibration audio being divided into constituent frames, the plurality of sound axes emit calibration audio during the corresponding time slot of each constituent frame; (b) record the emitted calibration audio via the microphone; (c) cause the processing device to respond to the time slot of the recorded calibration audio corresponding to the acoustic axis to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes; (d) such that a delay for each of the plurality of acoustic axes is determined, each determined delay the determined arrival times corresponding to the respective acoustic axes; and (e) causing the plurality of acoustic axes to be calibrated, wherein calibrating the plurality of acoustic axes comprises causing the plurality of acoustic axes to be delayed according to the respective determined delays audio output.

This specification is presented primarily in terms of illustrative environments, systems, processes, steps, logic blocks, processes, and other symbolic representations that directly or indirectly resemble the operation of a data processing device coupled to a network. These process descriptions and representations are commonly used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be understood by those skilled in the art that certain embodiments of the present disclosure may be practiced without certain specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. Accordingly, the scope of the present disclosure is to be defined by the appended claims rather than the foregoing description of the embodiments.

When any of the appended claims is construed to encompass a pure software and/or firmware implementation, at least one element of at least one example is expressly defined herein to include a tangible non-transitory medium storing software and/or firmware, Such as memory, DVD, CD, Blu-ray, etc.

Claims (16)

1. A method for a networked microphone device (NMD), the method comprising: detecting a trigger condition that initiates calibration of a media playback system for a plurality of playback configurations, each playback configuration representing a respective set of one or more sound axes formed via a plurality of audio drivers of the media playback system, wherein each sound axis corresponds to a corresponding input channel of the audio content; causing, via a network interface of the networked microphone device, each audio driver of the plurality of audio drivers of the media playback system to output calibration audio divided into repeated sets of frames comprising respective frames configured for each playback , and the calibration audio is output via the one or more acoustic axes corresponding to a given playback configuration during respective time slots of each frame corresponding to the respective playback configuration, such that during each of the set of frames During frames, a respective set of spatial filters is applied to the plurality of audio drivers, the respective set of spatial filters including for each of the one or more acoustic axes corresponding to the respective playback configuration a corresponding spatial filter for an axis, wherein the spatial filter spatially calibrates the media playback system to a given listening area by arranging the plurality of audio drivers to form a particular acoustic axis, at directing the sound output of the particular acoustic axis of the respective set of the one or more acoustic axes in a particular direction; recording the calibration audio output by the plurality of audio drivers via a microphone; and The processing device is caused to determine, based on the recorded calibration audio, respective sets of spectral filters for the plurality of playback configurations, each set of spectral filters including respective spectral filters for each acoustic axis. 2. The method of claim 1, further comprising causing the determined set of spectral filters corresponding to the given playback configuration to be applied when the media playback system plays back audio content in the given playback configuration on the acoustic axis formed by the plurality of audio drivers. 3. The method of claim 1 or 2, wherein causing the respective sets of spatial filters to be applied to the plurality of audio drivers comprises causing the processing device to apply the spatial filters to the calibration audio, and sending the calibrated audio with the spatial filter applied to one or more playback devices including the plurality of audio drivers. 4. The method of claim 1 or 2, wherein the media playback system comprises a plurality of playback devices, each playback device comprising a subset of the plurality of audio drivers. 5. The method of claim 1 or 2, wherein: In a surround playback configuration: each sound axis corresponds to a corresponding channel of surround audio content, and a first spatial filter corresponding to the surround sound playback configuration; In a stereo playback configuration: each sound axis corresponds to a corresponding channel of stereo audio content; and a second spatial filter corresponding to the stereo playback configuration; and In a mono playback configuration: the plurality of audio drivers form a single acoustic shaft; and The third spatial filter corresponds to the mono playback configuration. 6. The method of claim 5, wherein: the mono playback configuration is a first mono playback configuration, the stereo playback configuration is a first stereo playback configuration, the surround sound playback configuration is a first surround sound configuration; and The plurality of playback configurations includes at least one of the following playback configurations: A second mono playback configuration in which, upon playback of audio content, the plurality of audio drivers are configured to form one or more full-range sound shafts and subwoofer sound shafts to outputting mono audio content synchronously, wherein a fourth spatial filter corresponds to the second mono playback configuration; A second stereo playback configuration in which the plurality of audio drivers are configured to form one or more acoustic shafts to output the stereo content in synchronization with the subwoofer acoustic shaft when the audio content is played back in the second stereo playback configuration a channel of audio content, wherein a fifth spatial filter corresponds to the second stereo playback configuration; and A second surround sound playback configuration in which the plurality of audio drivers are configured to form one or more full-range sound axes to be synchronized with the subwoofer sound axis when the audio content is played back in the second surround sound playback configuration and outputting respective channels of surround sound content audio content, wherein the sixth spatial filter corresponds to the second surround sound playback configuration. 7. The method of claim 1 or 2, wherein the plurality of playback configurations comprises two or more of the following playback configurations: a music playback configuration in which, upon playback of audio content, the plurality of audio drivers are configured to form an acoustic axis to output music content, wherein a music playback spatial filter corresponds to the music playback configuration, and a home theater playback configuration in which, upon playback of audio content, the plurality of audio drivers are configured to form an acoustic axis to output audio content paired with the video content, wherein the home theater playback spatial filter corresponds to in the home theater playback configuration. 8. The method of claim 3, wherein the calibration audio is a second calibration audio, the method further comprising: prior to causing the plurality of audio drivers to output the second calibration audio, causing the plurality of audio drivers to output a first calibration audio, the first calibration audio being divided into components comprising for each of the plurality of playback configurations a repeated set of frames for the corresponding frames of the playback configuration; recording, via the microphone, the first calibration audio output by the plurality of audio drivers; and causing the processing device to determine the respective sets of spatial filters for the plurality of playback configurations based on the recorded first calibration audio, each set of spatial filters including a respective spatial filter for each acoustic axis . 9. The method of claim 8, wherein: the determined set of spatial filters calibrates the playback device to a particular listening position within a listening area of the playback device, and The determined spectral filter compensates for the acoustic properties of the listening area. 10. The method of claim 8, wherein: causing the plurality of audio drivers to output the first calibration audio includes causing the plurality of audio drivers to emit calibration audio via a plurality of acoustic axes at respective time slots in each frame, each acoustic axis corresponding to multi-channel audio the corresponding channel of the content; and Causing the processing device to determine the respective set of spatial filters includes: such that a respective spatial delay for each acoustic axis of the plurality of acoustic axes is determined based on the time slot corresponding to the acoustic axis in which the calibration audio was recorded, based on the respective determined delays, Wherein, such that determining the respective delay of each acoustic axis of the plurality of acoustic axes comprises: causing the processing device to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes based on a time slot for recording calibration audio corresponding to each acoustic axis; and A delay for each of the plurality of acoustic axes is caused to be determined, each determined delay corresponding to the determined time of arrival of the respective acoustic axis. 11. The method of claim 10, wherein causing the processing device to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes comprises: dividing the recorded calibration audio into constituent frames and dividing each constituent frame into a corresponding time slot for each acoustic axis; determining a respective impulse response of each acoustic axis from a respective time slot corresponding to the acoustic axis; aligning the respective impulse responses with a first reference point; identifying the corresponding second reference point in each impulse response; and determining the respective time of arrival at the microphone based on the respective difference between the first reference point and the second reference point in each impulse response, wherein the acoustic axis consists of a reference acoustic axis and one or more other acoustic axes, and wherein identifying a corresponding second reference point in each impulse response comprises: identifying a peak in the impulse response of the reference acoustic axis as a given second reference point; and In the time window following the given second reference point, the corresponding peaks of the impulse responses of the one or more other acoustic axes are identified as other second reference points. 12. The method of claim 10, wherein causing the processing device to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes comprises: Send via the network interface to the processing device: the recorded calibration audio, and instructions to determine a respective time of arrival at the microphone for each of the plurality of acoustic axes; and The determined respective arrival times are received via the network interface. 13. The method of claim 10, wherein causing the delay of each of the plurality of acoustic axes to be determined comprises: determine that the arrival time of a given acoustic axis exceeds a maximum delay threshold; and The delay for the given sound axis is caused to be set at the maximum delay threshold while the media playback system is playing back audio content paired with video content. 14. The method of claim 1 or 2, wherein detecting the triggering condition to initiate calibration of a media playback system comprises one of the following: detecting, via a user interface, input data indicating a command to initiate calibration of the media playback system; and The configuration of the media playback system is detected as a particular axis configuration, wherein the plurality of audio drivers form a particular set of acoustic axes. 15. A networked microphone device configured to perform the method of any of claims 1 to 14. 16. A media playback system comprising: The networked microphone device of claim 15; and A playback device configured to cause the audio level to apply a specific spectral filter corresponding to a given playback configuration when the audio content is played back in the given playback configuration.

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