WO2023084782A1 - Audio device, vehicle, and audio amplifier - Google Patents

Abstract

This audio device comprises a head unit, a first amplifier, and one or more audio modules. The head unit generates audio data and control data. The first amplifier is connected to the head unit and processes audio data on the basis of the control data. Each of the one or more audio modules is connected to the first amplifier via an audio bus capable of bidirectional communication through serial communication, and functions as an expanded function or an additional function with respect to the first amplifier.

Description

Audio equipment, vehicles and audio amplifiers

The present disclosure relates to audio devices, vehicles and audio amplifiers.

As an audio device having a head unit that outputs an audio signal, for example, Patent Document 1 discloses a car audio device connected to an in-vehicle LAN (Local Area Network) such as a CAN (Controller Area Network).

JP 2007-145182 A

Patent Document 1 does not describe transmission of an audio signal output from a car audio device. In general, the head unit is connected to a main amplifier that amplifies audio signals output from the head unit. In conventional audio devices, it is necessary to prepare in advance a plurality of types of main amplifiers with different functions in anticipation of requests from various users, resulting in an increase in cost.

In consideration of the above circumstances, one aspect of the present disclosure aims to provide an audio device that can easily implement function expansion or function addition to an audio amplifier.

In order to solve the above problems, an audio device according to a preferred aspect of the present disclosure includes: a head unit that outputs audio data and control data; and a head unit that is connected to the head unit and outputs the audio data based on the control data. and at least one audio module connected to said first amplifier via an audio bus capable of two-way communication by serial communication and serving as an extension or additional function to said first amplifier. Prepare.

An audio device according to another preferred aspect of the present disclosure includes a head unit that outputs audio data and control data; a first amplifier that is connected to the head unit and processes the audio data based on the control data; a second amplifier connected to the first amplifier via an audio bus capable of two-way communication by serial communication and processing the audio data based on the control data.

An audio device according to another preferred aspect of the present disclosure includes a head unit that outputs audio data and control data; a first amplifier that is connected to the head unit and processes the audio data based on the control data; an additional function module connected to the first amplifier via an audio bus capable of two-way communication by serial communication and generating additional audio data indicating a sound to be added to the sound indicated by the audio data; Additional audio data is input to the first amplifier via the audio bus.

A vehicle according to a preferred aspect of the present disclosure includes the audio device according to the aspect described above, and an in-vehicle bus connected to each of the head unit and the first amplifier.

An audio amplifier according to a preferred aspect of the present disclosure includes a first communication circuit connected via an in-vehicle bus to a head unit that outputs audio data and control data, and an audio bus capable of two-way communication by serial communication. a second communication circuit connected to the audio module via a communication protocol different from that of the in-vehicle bus to output the audio data and the control data; control behavior.

1 is a schematic diagram of an audio device according to a first embodiment; FIG. 3 is a diagram showing the configuration of a first amplifier and a second amplifier of the audio device according to the first embodiment; FIG. It is a schematic diagram of an audio device according to a second embodiment. It is a figure which shows the structure of the 1st amplifier of the audio apparatus which concerns on 2nd Embodiment, and a 2nd amplifier. FIG. 11 is a schematic diagram of an audio device according to a third embodiment; It is a figure which shows the structure of the 1st amplifier of the audio apparatus which concerns on 3rd Embodiment, and a 2nd amplifier. 1 is a diagram showing a vehicle according to an application example of an audio device; FIG.

1. First Embodiment Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the dimensions and scale of each part are appropriately different from the actual ones. Also, the embodiments described below are preferred specific examples of the present disclosure. Therefore, various technically preferable limitations are applied to the present embodiment. However, the scope of the present disclosure is not limited to these forms unless there is a description to the effect that the present disclosure is particularly limited in the following description.

1-1. Outline of Audio Device FIG. 1 is a schematic diagram of an audio device 10 according to the first embodiment. The audio device 10 is a device having audio functions that can be expanded or added. The audio device 10 is mounted in a vehicle such as an automobile, for example. An example of the vehicle will be described later with reference to FIG.

As shown in FIG. 1, the audio device 10 includes a head unit 20, a first amplifier 30, a second amplifier 40_1, a third amplifier 40_2, a fourth amplifier 40_3, an additional function module 40_4, speakers 80_1, 80_2, 80_3, and 80_4. Prepare.

Here, each of the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 is an example of an "audio module". Note that, hereinafter, each of the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 may be referred to as the audio module 40 in some cases.

The head unit 20 is a device that has a function of reproducing sound and a function of accepting operations such as volume adjustment from the user. Specifically, the head unit 20 is, for example, a device such as a radio receiver, a CD (Compact Disc) player, a DVD (Digital Versatile Disc) player, a navigation system, or a device combining two or more of these. . "CD" and "DVD" are registered trademarks.

The head unit 20 outputs audio data DA and control data DS. The audio data DA is data representing a reproduced sound, and is obtained, for example, by appropriately converting audio data read from a medium such as a CD, DVD, flash memory, or hard disk or input to an input terminal (not shown). . The format of the audio data DA is not particularly limited, and various known formats can be used. The control data DS is data indicating adjustment values such as reproduction volume, volume balance between left and right speakers, volume balance between front and rear speakers, equalizer or audio mode setting. The audio mode settings include, for example, a driver mode in which the volume balance is set so as to be suitable for listening by the driver, and an all-seat mode in which the volume balance is set so as to be suitable for listening in all seats. The control data DS is adjusted, for example, according to a user's operation on an operation unit (not shown).

The head unit 20 may have a function such as a road noise canceling function, a noise canceling function, a karaoke function, an ICC (In-car communication) function, or an equalizer function. In this case, the head unit 20 generates audio data similar to additional audio data DF, which will be described later. The audio data is transmitted from the head unit 20 to the first amplifier 30 via the bus 60 together with the audio data DA.

A first amplifier 30 is connected to the head unit 20 via an in-vehicle bus 50 and a bus 60 . Control data DS output from the head unit 20 is input to the first amplifier 30 via the vehicle-mounted bus 50 . Also, audio data DA output from the head unit 20 is input to the first amplifier 30 via the bus 60 .

The in-vehicle bus 50 is a communication network for mutual communication between multiple ECUs (Electronic Control Units) mounted in the vehicle. Here, each of the head unit 20 and the first amplifier 30 is a kind of the ECU. For example, the vehicle-mounted bus 50 is a vehicle bus using CAN as a communication protocol. Although not shown, the vehicle-mounted bus 50 is connected to the head unit 20 and the first amplifier 30 as well as a plurality of ECUs. The plurality of ECUs includes an ECU for diagnosis. The diagnostic ECU uses a diagnostic communication protocol such as UDS (Unified Diagnostic Service), for example, to diagnose failures of devices such as the head unit 20 and the first amplifier 30 connected to the in-vehicle bus 50 . In addition, the vehicle-mounted bus 50 is not limited to a bus using CAN, and may be, for example, a vehicle bus using a communication protocol other than CAN.

The bus 60 is a bus having communication lines for transmitting audio data DA from the head unit 20 to the first amplifier 30 using a communication protocol different from that of the vehicle-mounted bus 50 . The bus 60 is not particularly limited as long as it can transmit the audio data DA, and is, for example, an in-vehicle audio bus such as an ^A2B bus, AVB (Audio Video Bridging), or MOST (Media Oriented Systems Transport). be. " ^A2B " is a registered trademark. The communication protocol used for the bus 60 may be the same as or different from the communication protocol used for the audio bus 70 . Details of the A ² B bus will be described later together with the audio bus 70 .

The first amplifier 30 is an audio amplifier, and has a function of amplifying an audio signal based on the audio data DA, a function of controlling the operation of each audio module 40, and a function of acquiring the state data DD for fault diagnosis. and have

Specifically, the first amplifier 30 generates an audio signal based on the audio data DA by processing the audio data DA based on the control data DS. The audio signal is output from the first amplifier 30 after being amplified with an amplification factor based on the control data DS. Further, additional audio data DF is input to the first amplifier 30 via an audio bus 70, which will be described later, as required. Here, the first amplifier 30 processes the additional audio data DF in the same manner as the audio data DA, and outputs an audio signal indicating a synthesized sound of the sound indicated by the audio data DA and the sound indicated by the additional audio data DF.

The first amplifier 30 receives state data DD from the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 at a predetermined time such as when there is a request from the aforementioned diagnostic ECU or at startup. to get The state data DD acquired by the first amplifier 30 is input to the aforementioned diagnostic ECU via the vehicle bus 50 . The state data DD is data indicating states such as presence/absence of failure of the first amplifier 30, the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4. The state data DD is, for example, data in a format conforming to a diagnostic communication protocol such as UDS (Unified Diagnostic Service).

The first amplifier 30 outputs audio data DA and control data DS to the audio bus 70 . Here, the first amplifier 30 outputs command data to the audio bus 70 in addition to the audio data DA and the control data DS. The command data includes information indicating the audio module 40 to be processed with the audio data DA and the control data DS. Here, each of the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 is driven based on the command data from the first amplifier 30. FIG. That is, each of the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 functions as a replica with the first amplifier 30 as a primary. Details of the first amplifier 30 will be described later with reference to FIG.

A second amplifier 40_1, a third amplifier 40_2, a fourth amplifier 40_3 and an additional function module 40_4 are connected to the first amplifier 30 via an audio bus 70 . In the example shown in FIG. 1, a second amplifier 40_1, a third amplifier 40_2, a fourth amplifier 40_3, and an additional function module 40_4 are daisy-chained to the first amplifier 30 via an audio bus 70. FIG. Here, the first amplifier 30 and the second amplifier 40_1 are connected to each other via the cable 70a. Second amplifier 40_1 and third amplifier 40_2 are connected to each other via cable 70b. The third amplifier 40_2 and the fourth amplifier 40_3 are connected to each other via a cable 70c. The fourth amplifier 40_3 and the additional function module 40_4 are connected to each other via the cable 70d.

The audio data DA and control data DS output from the first amplifier 30 are input to the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 via the audio bus 70. .

The audio bus 70 is a bus capable of two-way communication through serial communication using a communication protocol different from that of the vehicle-mounted bus 50 . For example, audio bus 70 is an automotive audio bus such as an ^A2B bus. The ^A2B bus is a high-bandwidth, bi-directional digital audio bus that uses unshielded twisted-pair cables to serially transmit audio data DA and additional audio data DF, as well as control data DS and the aforementioned command data. It is possible.

The audio bus 70 transmits audio data DA, control data DS, additional audio data DF and status data DD between the head unit 20 and each audio module 40 . A frame format for data transmission on the audio bus 70 includes, for example, four data slots for downstream, upstream, control and response. The down data slot is used for transmitting audio data DA. The data slot for uplink is used for transmission of additional audio data DF. The control data slot is used for transmitting control data DS and command data. The response data slot is used to transmit response data such as status data DD output from the audio module 40 .

Each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 uses the audio data DA and the control data DS input via the audio bus 70 to function as an extended function for the first amplifier 30. module 40; The extended function is an audio amplifier function. That is, each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 is an audio amplifier. Each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 generates an audio signal based on the audio data DA by processing the audio data DA based on the control data DS. The audio signal is amplified by an amplification factor based on the control data DS, and then output from each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3. Additional audio data DF, which will be described later, is input to each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 as necessary. Here, each of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 processes the additional audio data DF in the same manner as the audio data DA, and the sound indicated by the audio data DA and the sound indicated by the additional audio data DF outputs an audio signal representing the synthesized sound of

Here, the configurations of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 may be the same or different. For example, specifications such as the number of channels, frequency characteristics, and rated output of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 may be the same or different. Details of the second amplifier 40_1 will be described later with reference to FIG.

The additional function module 40_4 is an audio module 40 that functions as an additional function for the first amplifier 30. The additional function is not particularly limited as long as it is an audio function that can be added to the first amplifier 30. For example, road noise canceling function, noise canceling function, karaoke function, ICC (In-car communication) function. , an equalizer function, and the like. The additional function module 40_4 has one or more of these functions.

The additional function module 40_4 generates additional audio data DF. The additional audio data DF is data indicating a sound added to the sound indicated by the audio data DA. For example, when the additional function module 40_4 has a road noise canceling function or a noise canceling function, the additional audio data DF is data indicating a canceled sound having the opposite phase to noise picked up by a microphone installed in the vehicle. be. If the additional function module 40_4 has a karaoke function or an ICC function, the additional audio data DF is data representing audio picked up by a microphone installed in the vehicle.

Here, audio data DA and control data DS are input to the additional function module 40_4 via the audio bus 70 as required. For example, the additional function module 40_4 adjusts the volume of the sound indicated by the additional audio data DF based on the control data DS, or switches whether or not to use the additional function, if necessary. For example, from the viewpoint of favorably using the road noise canceling function or the karaoke function, the additional function module 40_4 uses the additional function when the windows of the vehicle are closed based on the control data DS. If the window is opened, stop the additional function. Further, when the additional function module 40_4 has the road noise canceling function or the noise canceling function, the output value of the acceleration sensor and the audio data DA are used to cancel noise from the sound picked up by the microphone installed in the vehicle. Extract.

The additional function module 40_4 outputs additional audio data DF. Additional audio data DF output from additional function module 40_4 is input to first amplifier 30, second amplifier 40_1, third amplifier 40_2, and fourth amplifier 40_3 via audio bus 70, respectively.

Each of the speakers 80_1, 80_2, 80_3, and 80_4 is a device that converts an electrical audio signal into sound. In the example shown in FIG. 1 , the speaker 80_1 is connected to the first amplifier 30 and emits sound based on the audio signal output from the first amplifier 30 . The speaker 80_2 is connected to the second amplifier 40_1 and emits sound based on the audio signal output from the second amplifier 40_1. The speaker 80_3 is connected to the third amplifier 40_2 and emits sound based on the audio signal output from the third amplifier 40_2. The speaker 80_4 is connected to the fourth amplifier 40_3 and emits sound based on the audio signal output from the fourth amplifier 40_3.

Note that in FIG. 1, each of the speakers 80_1, 80_2, 80_3, and 80_4 is shown as one speaker for convenience. However, typically, each of the speakers 80_1, 80_2, 80_3, and 80_4 is composed of a plurality of speakers, as described later based on FIG. Here, the configurations of the speakers 80_1, 80_2, 80_3, and 80_4 may be the same or different. For example, the specifications such as the sizes, frequency characteristics, and rated outputs of the speakers 80_1, 80_2, 80_3, and 80_4 may be the same or different. Each of the speakers 80_1, 80_2, 80_3, and 80_4 may be referred to as a speaker 80 below.

1-2. First Amplifier and Audio Module FIG. 2 is a diagram showing configurations of the first amplifier 30 and the second amplifier 40_1 of the audio device 10 according to the first embodiment. In FIG. 2, illustration of the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 is omitted. Below, the second amplifier 40_1 of the plurality of audio modules 40 will be described as a representative. Note that each of the third amplifier 40_2 and the fourth amplifier 40_3 is configured similarly to the second amplifier 40_1. The additional function module 40_4 is configured in the same manner as the second amplifier 40_1 except that it has the aforementioned additional function instead of the amplifier function.

As shown in FIG. 2, the head unit 20 has a communication circuit 21 and a communication circuit 22. The communication circuit 21 is a transceiver for data transmission using the vehicle-mounted bus 50 and is connected to a node of the vehicle-mounted bus 50 . The communication circuit 21 transmits control data DS to the vehicle-mounted bus 50 and receives status data DD from the vehicle-mounted bus 50 . Communication circuit 22 is a transceiver for data transmission using bus 60 and is connected to a node of bus 60 . Communication circuit 22 transmits audio data DA to bus 60 .

The first amplifier 30 has communication circuits 31 , 33 and 37 , processing circuits 32 and 34 , a storage circuit 35 and an amplifier circuit 36 . Here, the communication circuit 31 is an example of a "first communication circuit". The communication circuit 37 is an example of a "second communication circuit".

The communication circuit 31 is a transceiver for data transmission using the vehicle-mounted bus 50 and is connected to a node of the vehicle-mounted bus 50 . Therefore, the communication circuit 31 is connected to the head unit 20 via the vehicle-mounted bus 50 . The communication circuit 31 receives control data DS from the vehicle bus 50 and transmits status data DD to the vehicle bus 50 using a communication protocol for the vehicle bus 50 .

The processing circuit 32 is an integrated circuit such as an MCU (Micro Control Unit) that controls the operation of each part of the first amplifier 30 based on the control data DS from the communication circuit 31 .

The communication circuit 33 is a transceiver for data transmission using the bus 60 and is connected to nodes of the bus 60 . Therefore, the communication circuit 33 is connected to the head unit 20 via the bus 60 . Communication circuit 33 receives audio data DA from bus 60 using the communication protocol for bus 60 .

The processing circuit 34 is a processor such as a DSP (digital signal processor) that processes the audio data DA from the communication circuit 33 based on the control data DS from the processing circuit 32 . For example, the processing circuit 34 adjusts the audio characteristics such as the frequency characteristics of the sound indicated by the audio data DA based on the control data DS, and performs digital signal processing on the audio data DA so that it is output in a predetermined number of channels. . In the example shown in FIG. 2, processing circuitry 34 outputs twelve channels of audio signals. Part or all of the processing circuit 34 may be configured as an integrated circuit integrated with the processing circuit 32 .

The storage circuit 35 stores various programs to be executed by the processing circuit 34 and various data to be processed by the processing circuit 34. The storage circuit 35 is, for example, a combination of volatile memory such as RAM (Random Access Memory) and non-volatile memory such as ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory) or PROM (Programmable ROM). Includes one or both semiconductor memories.

The amplifier circuit 36 amplifies the audio signal from the processing circuit 34 based on the control data DS. In the example shown in FIG. 2, the amplifier circuit 36 has an amplifier circuit 36a, an amplifier circuit 36b, and an amplifier circuit 36c, and amplifies 12-channel audio signals. Each of the amplifier circuit 36a, the amplifier circuit 36b, and the amplifier circuit 36c is an amplifier circuit such as a class AB amplifier circuit or a class D amplifier circuit for amplifying four-channel audio signals. Here, four speakers 80_1 are connected to each of the amplifier circuit 36a, the amplifier circuit 36b, and the amplifier circuit 36c. Therefore, 12 speakers 80_1 are connected to the amplifier circuit 36 . The amplifier circuit 36 is not limited to the configuration shown in FIG. 2, and for example, the amplifier circuit 36a, the amplifier circuit 36b, and the amplifier circuit 36c may be integrally configured.

The communication circuit 37 is a transceiver for data transmission using the audio bus 70 and is connected to a node of the audio bus 70. Therefore, the communication circuit 37 is connected to each audio module 40 via the audio bus 70 . In the example shown in FIG. 2, the communication circuit 37 is connected to the second amplifier 40_1 via the cable 70a. The communication circuit 37 uses the communication protocol for the audio bus 70 to transmit audio data DA and control data DS to the audio bus 70 and receive additional audio data DF and status data DD from the audio bus 70. or Here, the communication circuit 37 transmits command data for requesting acquisition of the state data DD to the audio bus 70 as necessary.

As described above, the first amplifier 30, which is an example of the "audio amplifier," includes the communication circuit 31, which is an example of the "first communication circuit," and the communication circuit 37, which is an example of the "second communication circuit." and controls the operation of the audio module 40 based on the control data DS. The communication circuit 31 is connected to the head unit 20 via the vehicle-mounted bus 50 . Therefore, the head unit 20 and the first amplifier 30 can communicate with each other. Therefore, the device such as the head unit 20 connected to the vehicle-mounted bus 50 can control the first amplifier 30 and provide information on the first amplifier 30 to the device. The communication circuit 37 is also connected to the audio module 40 via the audio bus 70 and outputs audio data DA and control data DS using a communication protocol different from that of the in-vehicle bus 50 . Therefore, the audio module 40 and the first amplifier 30 can communicate with each other. Moreover, since the communication circuit 37 outputs the audio data DA and the control data DS, the operation of the audio module 40 can be controlled as if the audio module 40 were part of the first amplifier 30 . Also, the configuration for controlling the operation of the audio module 40 can be simplified and the processing load of the audio module 40 can be reduced.

The second amplifier 40_1 has a communication circuit 41, a processing circuit 42, a storage circuit 43, and an amplifier circuit 44.

The communication circuit 41 is a transceiver for data transmission using the audio bus 70 and is connected to a node of the audio bus 70. Therefore, the communication circuit 41 is connected to each of the first amplifier 30 and other audio modules 40 via the audio bus 70 . In the example shown in FIG. 2, the communication circuit 41 is connected to the communication circuit 37 of the first amplifier 30 via a cable 70a, and is connected to the third amplifier 40_2 via a cable 70b (not shown in FIG. 2). Connected. Communication circuit 41 uses the communication protocol for audio bus 70 to receive audio data DA and control data DS from cable 70a and to transmit additional audio data DF and status data DD to cable 70a. Communication circuit 41 also uses the communication protocol for audio bus 70 to transmit audio data DA and control data DS to cable 70b, and to receive additional audio data DF and status data DD from cable 70a. do.

The processing circuit 42 is a processor such as a DSP that processes the audio data DA from the communication circuit 41 based on the control data DS from the communication circuit 41 . For example, the processing circuit 42 adjusts the audio characteristics such as the frequency characteristics of the sound indicated by the audio data DA based on the control data DS, and performs digital signal processing on the audio data DA so that it is output in a predetermined number of channels. . In the example shown in FIG. 2, the processing circuit 42 outputs four channels of audio signals.

The storage circuit 43 stores various programs to be executed by the processing circuit 42 and various data to be processed by the processing circuit 34 . The storage circuit 43 includes, for example, one or both of a volatile memory such as a RAM and a non-volatile memory such as a ROM, EEPROM or PROM.

The amplifier circuit 44 amplifies the audio signal from the processing circuit 42 based on the control data DS. In the example shown in FIG. 2, the amplifier circuit 44 is an amplifier circuit such as a class AB amplifier circuit or a class D amplifier circuit that amplifies four-channel audio signals. Four speakers 80_1 are connected to the amplifier circuit 44 .

As described above, the audio device 10 includes the head unit 20, the first amplifier 30, and the plurality of audio modules 40. The head unit 20 outputs audio data DA and control data DS. The first amplifier 30 is connected to the head unit 20 and processes audio data DA based on control data DS. Each of the plurality of audio modules 40 is connected to the first amplifier 30 via an audio bus 70 capable of two-way communication by serial communication, and functions as an extended function or additional function for the first amplifier 30 .

In the audio device 10 described above, the audio module 40 functions as an extended function or an additional function for the first amplifier 30. Therefore, without replacing the first amplifier 30, by appropriately adding the audio module 40, the first Multifunctionality or high performance of the amplifier 30 can be achieved. Therefore, even if a plurality of types of first amplifiers 30 having different functions are not prepared in advance, the type, number, combination, etc. of the audio modules 40 used in the audio device 10 can be appropriately changed, thereby reducing the cost while achieving the first amplifier. Diversification or high functionality of the 1 amplifier 30 can be achieved.

Here, since the first amplifier 30 and the audio module 40 are connected to each other via the audio bus 70 capable of two-way communication, communication necessary for extension functions or additional functions to the first amplifier 30 can be performed with the first amplifier 30. It can be performed with the audio module 40 . Also, the operations of the first amplifier 30 and the audio module 40 can be controlled based on the control data DS from the head unit 20 . Moreover, since the audio bus 70 is a serial bus, it is possible to reduce the increase in the number of wires due to the addition of the audio module 40 compared to a configuration using a parallel bus. As can be understood from the above, function expansion or function addition to the first amplifier 30 can be easily achieved.

Here, as described above, the first amplifier 30 is connected to the head unit 20 via the vehicle-mounted bus 50 that uses a communication protocol different from that of the audio bus 70 . Therefore, it is possible to control the head unit 20 or the first amplifier 30 by another device connected to the in-vehicle bus 50, or to provide information on the head unit 20 or the first amplifier 30 to the other device. . Therefore, it is possible to provide the in-vehicle audio device 10 that is highly convenient.

Also, as described above, the control data DS is input to the first amplifier 30 from the head unit 20 via the in-vehicle bus 50 . In this manner, the vehicle-mounted bus 50 can be effectively used for inputting the control data DS to the first amplifier 30 . Therefore, since a separate bus for transmitting the control data DS from the head unit 20 to the first amplifier 30 is not required, the number of wires can be reduced.

In the present embodiment, as described above, audio data DA is input from the head unit 20 to the first amplifier 30 via the bus 60 that uses a different communication protocol than the in-vehicle bus 50 . Therefore, even if the vehicle-mounted bus 50 is not suitable for transmitting the audio data DA, the audio data DA can be input to the first amplifier 30 using the bus 60 .

Also, as described above, the first amplifier 30 controls the operation of each of the at least one audio module 40 based on the control data DS. Therefore, the first amplifier 30 can function as a primary with the audio module 40 as a replica. Therefore, it is not necessary to connect the audio module 40 to the head unit 20 . As a result, compared to the configuration in which the audio module 40 is connected to the head unit 20, wiring can be simplified.

Furthermore, as described above, multiple audio modules 40 are daisy-chained. Therefore, the number of wires of the audio bus 70 can be reduced and the routing of the wires of the audio bus 70 can be simplified as compared with other connection modes.

Also, as described above, state data DD indicating the state of the audio module 40 is input to the first amplifier 30 via the audio bus 70 . The first amplifier 30 then outputs the state data DD to the vehicle bus 50 . Therefore, the state data DD can be provided to other devices such as a diagnostic ECU connected to the vehicle-mounted bus 50 . Therefore, it is possible to grasp the failure state of the audio module 40 by the other device.

In this embodiment, the audio device 10 includes the second amplifier 40_1 as the audio module 40, as described above. The second amplifier 40_1 processes the audio data DA based on the control data DS. Therefore, the function of the first amplifier 30 can be expanded by the second amplifier 40_1. For example, the number of amplifier channels can be increased without replacing the first amplifier 30 with a multi-channel amplifier.

Here, as described above, the second amplifier 40_1 includes the processing circuit 42 that performs digital signal processing on the audio data DA. Therefore, the audio signal based on the audio data DA can be output from the second amplifier 40_1 with characteristics different from those of the first amplifier 30 . Moreover, since digital signal processing is used, the amount of information of the audio data DA can be reduced compared to a configuration using analog signal processing.

The audio device 10 also includes the additional function module 40_4 as the audio module 40, as described above. The additional function module 40_4 generates additional audio data DF indicating sounds to be added to the sounds indicated by the audio data DA. The additional audio data DF is input to the first amplifier 30 via the audio bus 70 . Therefore, the function of the additional function module 40_4 can be added to the first amplifier 30 .

2. Second Embodiment A second embodiment of the present disclosure will be described below. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 3 is a schematic diagram of an audio device 10A according to the second embodiment. The audio device 10A has the first audio system except that the bus 60 is omitted and the head unit 20A, the first amplifier 30A and the vehicle-mounted bus 50A are provided instead of the head unit 20, the first amplifier 30 and the vehicle-mounted bus 50. It is configured in the same manner as the audio device 10 of the embodiment.

The head unit 20A is configured similarly to the head unit 20, except that data transmission using the vehicle-mounted bus 50A is possible. A first amplifier 30A is connected to the head unit 20A via an in-vehicle bus 50A. The in-vehicle bus 50A is an in-vehicle Ethernet capable of transmitting audio data DA in addition to the same functions as the in-vehicle bus 50 . The in-vehicle bus 50A uses, for example, synchronization technology such as AVB (Audio Video Bridging).

The head unit 20A may have functions such as a road noise canceling function, a noise canceling function, a karaoke function, an ICC function, or an equalizer function. In this case, the head unit 20A generates audio data similar to the aforementioned additional audio data DF. The audio data is transmitted together with the audio data DA from the head unit 20A to the first amplifier 30A via the vehicle-mounted bus 50A.

The audio data DA and control data DS output from the head unit 20A are input to the first amplifier 30A via the vehicle-mounted bus 50A. The first amplifier 30A is configured in the same manner as the first amplifier 30 except that data transmission using the vehicle bus 50A is possible.

FIG. 4 is a diagram showing configurations of the first amplifier 30A and the second amplifier 40_1 of the audio device 10A according to the second embodiment. In FIG. 4, illustration of the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 is omitted.

As shown in FIG. 4, the head unit 20A is configured in the same manner as the head unit 20 except that it has a communication circuit 23 instead of the communication circuits 21 and 22. The communication circuit 23 is a transceiver for data transmission using the vehicle-mounted bus 50A, and is connected to a node of the vehicle-mounted bus 50A. The communication circuit 23 transmits audio data DA and control data DS to the vehicle-mounted bus 50A, and receives status data DD from the vehicle-mounted bus 50A.

The first amplifier 30A is configured in the same manner as the first amplifier 30 except that it has a communication circuit 38 instead of the communication circuits 31 and 33. The communication circuit 38 is a transceiver for data transmission using the vehicle-mounted bus 50A, and is connected to a node of the vehicle-mounted bus 50A. The communication circuit 38 receives audio data DA and control data DS from the vehicle-mounted bus 50A, and transmits status data DD to the vehicle-mounted bus 50A.

According to the above-described second embodiment, similarly to the first embodiment, it is possible to easily realize function expansion or function addition to the first amplifier 30A. In this embodiment, as described above, audio data DA is input from the head unit 20A to the first amplifier 30A via the vehicle-mounted bus 50A. Therefore, since a separate bus for transmitting the audio data DA from the head unit 20A to the first amplifier 30A is not required, the number of wires can be reduced.

3. Third Embodiment A third embodiment of the present disclosure will be described below. In the embodiments exemplified below, the reference numerals used in the description of the first embodiment are used for the elements having the same actions and functions as those of the first embodiment, and the detailed description of each element is appropriately omitted.

FIG. 5 is a schematic diagram of an audio device 10B according to the third embodiment. Audio device 10B has the same configuration as the first amplifier except that bus 60 is omitted and head unit 20B, first amplifier 30B and audio bus 70B are provided instead of head unit 20, first amplifier 30 and audio bus 70. It is configured in the same manner as the audio device 10 of the embodiment.

The head unit 20B is configured similarly to the head unit 20, except that data transmission using the audio bus 70B is possible. The head unit 20B is connected to the first amplifier 30B via the vehicle bus 50 and the audio bus 70B. Audio data DA output from the head unit 20B is input to the first amplifier 30B via the audio bus 70B. The first amplifier 30B is configured similarly to the first amplifier 30, except that data transmission using the audio bus 70B is possible.

The audio bus 70B is configured in the same manner as the audio bus 70, except that a cable 70e connecting the head unit 20B and the additional function module 40_4 is added. Here, each of the head unit 20B, the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3 and the additional function module 40_4 is driven based on the command data from the first amplifier 30B. That is, not only the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3 and the additional function module 40_4, but also the head unit 20B functions as a replica whose primary is the first amplifier 30B.

FIG. 6 is a diagram showing configurations of the first amplifier 30B and the second amplifier 40_1 of the audio device 10B according to the third embodiment. In FIG. 6, illustration of the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 is omitted.

As shown in FIG. 6, the head unit 20B is configured in the same manner as the head unit 20 except that it has a communication circuit 24 instead of the communication circuit 22. The communication circuit 24 is a transceiver for data transmission using the audio bus 70B, and is connected to a node of the audio bus 70B. The communication circuit 24 transmits audio data DA and control data DS to the audio bus 70B and receives status data DD from the audio bus 70B.

The first amplifier 30B is configured similarly to the first amplifier 30, except that the communication circuit 33 is omitted. Here, the communication circuit 37 transmits control data DS to the audio bus 70 and receives audio data DA, additional audio data DF and status data DD from the audio bus 70 .

According to the above-described second embodiment, similarly to the first embodiment, it is possible to easily realize function expansion or function addition to the first amplifier 30A. In this embodiment, as described above, the first amplifier 30B is connected to the head unit 20B via the audio bus 70B. Audio data DA is input to the first amplifier 30B from the head unit 20B via the audio bus 70B. Therefore, even if the vehicle-mounted bus 50 is not suitable for transmitting the audio data DA, the audio data DA can be input to the first amplifier 30B using the audio bus 70B. Therefore, since a separate bus for transmitting the audio data DA from the head unit 20B to the first amplifier 30B is not required, the number of wires can be reduced.

4. Vehicle FIG. 7 is a diagram showing a vehicle 100 according to an application example of the audio device 10. As shown in FIG. FIG. 7 schematically shows an arrangement example of each part of the audio device 10 mounted on the vehicle 100. As shown in FIG. A vehicle 100 includes an audio device 10 and an in-vehicle bus 50 .

In the example shown in FIG. 7, 24 speakers 80 are installed in the vehicle 100. Specifically, right front door 101R, left front door 101L, right rear door 102R, left rear door 102L, dashboard 103, right A pillar 104R, left A pillar 104L, right front seat 105R, left front seat 105L, right One or more and three or less speakers 80 are installed in each of C-pillar 106R, left C-pillar 106L and trunk room 107 . Also, each of the head unit 20 and the first amplifier 30 is arranged near the dashboard 103 . A second amplifier 40_1 is arranged near the left front seat. Third amplifier 40_2, fourth amplifier 40_3 and additional function module 40_4 are arranged near trunk room 107, respectively. Note that the arrangement of each unit of the audio device 10 is not limited to the example shown in FIG. 7, and is arbitrary.

The vehicle 100 described above includes the audio device 10 and the vehicle-mounted bus 50 connected to the head unit 20 and the first amplifier 30, respectively, as described above. In the vehicle 100 described above, the multifunctionality and high performance of the audio device 10 can be easily achieved, so that the vehicle 100 having an audio space with characteristics according to the needs of the user can be provided at a low cost.

5. Modifications The present disclosure is not limited to the above-described embodiments, and various modifications described below are possible. Further, each embodiment and each modification may be combined as appropriate.

5-1. Modification 1
In each of the above embodiments, a configuration using four audio modules 40 is exemplified, but the configuration is not limited to this configuration, and the number of audio modules 40 may be 1 or more and 3 or less, or may be 5 or more. .

Here, at least one of the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 may be omitted, or an amplifier other than these amplifiers may be added as the audio module 40. Also, the additional function module 40_4 may be omitted, or one or more additional function modules other than the additional function module 40_4 may be added as an audio module. Also, the configurations of the plurality of audio modules 40 may be the same or different.

5-2. Modification 2
In each of the above-described forms, a configuration in which the first amplifier 30, the second amplifier 40_1, the third amplifier 40_2, the fourth amplifier 40_3, and the additional function module 40_4 are connected in this order is exemplified. The order in which the plurality of audio modules 40 are connected to the first amplifier 30 is arbitrary.

5-3. Modification 3
In each of the above-described forms, a configuration in which the audio devices 10, 10A, and 10B are mounted on a vehicle is exemplified, but the configuration is not limited to this configuration. For example, the audio devices 10, 10A, and 10B may be mounted on moving bodies other than vehicles, or may be installed in buildings such as residences, shops, and offices. Here, instead of the in-vehicle buses 50 and 50A, a network other than the in-vehicle LAN (Local Area Network) may be used.

5-4. Modification 4
Although each of the above-described embodiments exemplifies a configuration in which the number of channels of each of the audio devices 10, 10A, and 10B is 24, the configuration is not limited to this configuration, and the number of channels is arbitrary. Further, the number of channels of each of the first amplifier 30, the second amplifier 40_1, the third amplifier 40_2, and the fourth amplifier 40_3 is not limited to the form described above, and is arbitrary.

6. Supplementary Note The following aspects, for example, can be grasped from the embodiments or modifications illustrated above.

An audio device according to a preferred aspect (first aspect) of the present disclosure includes a head unit that outputs audio data and control data, and a first head unit that is connected to the head unit and processes the audio data based on the control data. an amplifier; and at least one audio module connected to the first amplifier via an audio bus capable of bi-directional communication by serial communication and serving as an extension or additional function to the first amplifier.

According to the above aspect, since the audio module functions as an extended function or an additional function for the first amplifier, the first amplifier can be multifunctional by appropriately adding the audio module without replacing the first amplifier. It is possible to improve the performance or improve the performance. Therefore, even if a plurality of types of first amplifiers having different functions are not prepared in advance, the type, number, combination, etc. of the audio modules used in the audio device can be appropriately changed, thereby reducing the cost and increasing the number of first amplifiers. Diversification or high functionality can be achieved.

Here, since the first amplifier and the audio module are connected to each other via an audio bus capable of bi-directional communication, communication necessary for extension or addition of functions to the first amplifier is carried out between the first amplifier and the audio module. can be done between Also, the operations of the first amplifier and the audio module can be controlled based on the control data from the head unit. Moreover, since the audio bus is a serial bus, it is possible to reduce the increase in the number of wires due to the addition of the audio module, compared to a configuration using a parallel bus. As can be understood from the above, it is possible to easily implement function expansion or function addition to the first amplifier.

In a preferred example of the first aspect (second aspect), at least one of the at least one audio module is a second amplifier that processes the audio data based on the control data. In the above aspect, the function of the first amplifier can be expanded by the second amplifier. For example, the number of amplifier channels can be increased without replacing the first amplifier with a multi-channel amplifier.

In the preferred example of the second aspect (third aspect), the second amplifier includes a processing circuit that performs digital signal processing on the audio data. In the above aspect, an audio signal based on audio data can be output from the second amplifier with characteristics different from those of the first amplifier. Also, since digital signal processing is used, the information amount of audio data can be reduced compared to a configuration using analog signal processing.

In a preferred example (fourth aspect) of any one of the first to third aspects, the first amplifier is connected to the head unit via an in-vehicle bus using a communication protocol different from that of the audio bus. . In the above aspect, it is possible to control the head unit or the first amplifier by another device connected to the in-vehicle bus, or to provide information on the head unit or the first amplifier to the other device. Therefore, it is possible to provide an in-vehicle audio device that is highly convenient.

In the preferred example of the fourth aspect (fifth aspect), the control data is input to the first amplifier from the head unit via the vehicle-mounted bus. In the above aspect, the vehicle-mounted bus can be effectively used for inputting the control data to the first amplifier. Therefore, since a separate bus for transmitting control data from the head unit to the first amplifier is not required, the number of wires can be reduced.

In the preferred example of the fourth aspect or fifth aspect (sixth aspect), the audio data is input to the first amplifier from the head unit via a bus different from the in-vehicle bus. In the above aspect, even if the vehicle-mounted bus is not suitable for transmitting audio data, the bus can be used to input audio data to the first amplifier.

In the preferred example of the fourth aspect or fifth aspect (seventh aspect), the audio data is input to the first amplifier from the head unit via the vehicle-mounted bus. In the above aspect, since a separate bus for transmitting audio data from the head unit to the first amplifier is not required, the number of wires can be reduced.

In a preferred example (eighth aspect) of the fourth aspect or the fifth aspect (eighth aspect), the first amplifier is connected to the head unit via the audio bus, and the first amplifier is connected to the head unit via the audio bus. , the audio data is input from the head unit. In the above aspect, even if the vehicle-mounted bus is not suitable for audio data transmission, the audio data can be input to the first amplifier using the audio bus. Therefore, since a separate bus for transmitting audio data from the head unit to the first amplifier is not required, the number of wires can be reduced.

In a preferred example (ninth aspect) of any one of the fourth aspect to the eighth aspect, state data indicating the state of the at least one audio module is input to the first amplifier via the audio bus, The first amplifier outputs the state data to the vehicle bus. In the above aspect, status data can be provided to other devices connected to the vehicle bus. Therefore, it is possible for the other device to grasp the state of the audio module, such as a failure.

In any one of the first to ninth aspects (tenth aspect), the first amplifier controls the operation of each of the at least one audio module based on the control data. In the above aspect, the first amplifier can function as a primary with the audio module as a replica. Therefore, no audio module needs to be connected to the head unit. As a result, the routing of wiring can be simplified compared to the configuration in which the audio module is connected to the head unit.

In the preferred example of any one of the first to tenth aspects (eleventh aspect), the at least one audio module includes a plurality of daisy-chained audio modules. In the above mode, the number of wires for the audio bus can be reduced, and the routing of the wires for the audio bus can be simplified, compared to other connection modes.

In a preferred example of any one of the first to eleventh aspects (twelfth aspect), at least one of the at least one audio module includes additional audio data indicating a sound to be added to the sound indicated by the audio data. and the additional audio data is input to the first amplifier via the audio bus. According to the above aspect, the function of the additional function module can be added to the first amplifier.

An audio device according to a preferred aspect (a thirteenth aspect) of the present disclosure includes a head unit that outputs audio data and control data, and a first head unit that is connected to the head unit and processes the audio data based on the control data. and a second amplifier connected to the first amplifier via an audio bus capable of two-way communication by serial communication and processing the audio data based on the control data.

According to the above aspect, since the second amplifier expands the function of the first amplifier, by appropriately adding the second amplifier, the first amplifier can be multifunctional or High functionality can be achieved. Here, since the first amplifier and the second amplifier are connected to each other via an audio bus capable of bi-directional communication, communication necessary for extended functions for the first amplifier is performed between the first amplifier and the second amplifier. It can be carried out. Also, the operations of the first amplifier and the second amplifier can be controlled based on the control data from the head unit. Moreover, since the audio bus is a serial bus, it is possible to reduce the increase in the number of wires due to the addition of the second amplifier, compared to a configuration using a parallel bus. As can be understood from the above, it is possible to easily implement functional expansion for the first amplifier.

An audio device according to a preferred aspect (a fourteenth aspect) of the present disclosure includes a head unit that outputs audio data and control data, and a first head unit that is connected to the head unit and processes the audio data based on the control data. an amplifier, and an additional function module connected to the first amplifier via an audio bus capable of two-way communication by serial communication and generating additional audio data indicating a sound to be added to the sound indicated by the audio data; The additional audio data is input to the first amplifier via the audio bus.

According to the above aspect, since the additional function module adds the function based on the additional audio data to the first amplifier, the additional function module can be appropriately added without replacing the first amplifier with a multi-function or high-performance amplifier. By adding the first amplifier, it is possible to increase the number of functions or increase the functionality of the first amplifier. Here, since the first amplifier and the additional function module are connected to each other via the audio bus capable of bi-directional communication, communication necessary for the additional function to the first amplifier is performed between the first amplifier and the additional function module. It can be carried out. Also, the operations of the first amplifier and the additional function module can be controlled based on the control data from the head unit. Moreover, since the audio bus is a serial bus, it is possible to reduce the increase in the number of wires due to the addition of additional function modules, compared to a configuration using a parallel bus. As can be understood from the above, it is possible to easily add functions to the first amplifier.

A vehicle according to a preferred aspect (a fifteenth aspect) of the present disclosure includes the audio device according to any one of the aspects described above, and an in-vehicle bus connected to each of the head unit and the first amplifier. According to the above aspect, it is possible to easily increase the number of functions and increase the functionality of the audio device, and thus it is possible to provide a vehicle having an audio space with characteristics according to the user's needs at a low cost.

An audio amplifier according to a preferred aspect (sixteenth aspect) of the present disclosure is capable of two-way communication through serial communication with a first communication circuit connected via an in-vehicle bus to a head unit that outputs audio data and control data. a second communication circuit connected to an audio module via an audio bus and outputting the audio data and the control data using a communication protocol different from that of the in-vehicle bus; to control the operation of the audio module.

According to the above aspect, since the head unit and the first communication circuit are connected to each other via the vehicle-mounted bus, the head unit and the audio amplifier can communicate with each other. Therefore, it is possible to control the audio amplifier with a device such as a head unit connected to the vehicle bus and to provide information on the audio amplifier to the device. In addition, since the audio module and the second communication circuit are connected to each other via the audio bus capable of two-way communication by serial communication using a communication protocol different from that of the vehicle-mounted bus, the audio module and the audio amplifier can communicate with each other. It can be carried out. Moreover, since the second communication circuit outputs audio data and control data, the operation of the audio module can be controlled as if the audio module were part of an audio amplifier. Also, the configuration for controlling the operation of the audio module can be simplified, and the processing load of the audio module can be reduced. As can be understood from the above, it is possible to provide an audio amplifier with excellent convenience.

DESCRIPTION OF SYMBOLS 10... Audio apparatus, 10A... Audio apparatus, 10B... Audio apparatus, 20... Head unit, 20A... Head unit, 20B... Head unit, 21... Communication circuit, 22... Communication circuit, 23... Communication circuit, 24... Communication circuit, 30... First amplifier 30A... First amplifier 30B... First amplifier 31... Communication circuit (first communication circuit) 32... Processing circuit 33... Communication circuit 34... Processing circuit 35... Storage circuit 36 Amplifier circuit 36a Amplifier circuit 36b Amplifier circuit 36c Amplifier circuit 37 Communication circuit (second communication circuit) 38 Communication circuit 40 Audio module 40_1 Second amplifier (audio module) 40_2... Third amplifier (audio module), 40_3... Fourth amplifier (audio module), 40_4... Additional function module (audio module), 41... Communication circuit, 42... Processing circuit, 43... Storage circuit, 44... Amplifier circuit, 50 Vehicle-mounted bus 50A Vehicle-mounted bus 60 Bus 70 Audio bus 70B Audio bus 70a Cable 70b Cable 70c Cable 70d Cable 70e Cable 80 Speaker 80_1 Speaker 80_2 Speaker 80_3 Speaker 80_4 Speaker 100 Vehicle 101L Left front door 101R Right front door 102L Left rear door 102R Right rear door 103 Dashboard , 104L...Left A-pillar, 104R...Right A-pillar, 105L...Left front seat, 105R...Right front seat, 106L...Left C pillar, 106R...Right C pillar, 107...Trunk room, 770...Audio bus, DA...Audio data, DD...state data, DF...additional audio data, DS...control data.

Claims (16)

a head unit that outputs audio data and control data;
a first amplifier connected to the head unit and processing the audio data based on the control data;
at least one audio module connected to the first amplifier via an audio bus capable of two-way communication by serial communication and functioning as an extended function or additional function to the first amplifier;
audio device. at least one of the at least one audio module is a second amplifier that processes the audio data based on the control data;
2. Audio device according to claim 1. the second amplifier includes a processing circuit that performs digital signal processing on the audio data;
3. Audio device according to claim 2. The first amplifier is connected to the head unit via an in-vehicle bus that uses a communication protocol different from that of the audio bus.
4. An audio device according to any one of claims 1-3. The control data is input to the first amplifier from the head unit via the in-vehicle bus.
5. Audio device according to claim 4. The audio data is input to the first amplifier from the head unit via a bus using a communication protocol different from that of the in-vehicle bus.
6. Audio device according to claim 4 or 5. The audio data is input to the first amplifier from the head unit via the in-vehicle bus.
6. Audio device according to claim 4 or 5. The first amplifier is connected to the head unit via the audio bus,
The audio data is input to the first amplifier from the head unit via the audio bus.
6. Audio device according to claim 4 or 5. state data indicating a state of the at least one audio module is input to the first amplifier via the audio bus;
The first amplifier outputs the state data to the vehicle bus.
9. An audio device according to any one of claims 4-8. the first amplifier controls operation of each of the at least one audio module based on the control data;
10. An audio device according to any one of claims 1-9. the at least one audio module includes a plurality of daisy-chained audio modules;
11. An audio device according to any one of claims 1-10. at least one of the at least one audio module is an additional function module that generates additional audio data indicating a sound added to the sound indicated by the audio data;
the additional audio data is input to the first amplifier via the audio bus;
12. An audio device according to any one of claims 1-11. a head unit that outputs audio data and control data;
a first amplifier connected to the head unit and processing the audio data based on the control data;
a second amplifier connected to the first amplifier via an audio bus capable of two-way communication by serial communication and processing the audio data based on the control data;
audio device. a head unit that outputs audio data and control data;
a first amplifier connected to the head unit and processing the audio data based on the control data;
an additional function module connected to the first amplifier via an audio bus capable of two-way communication by serial communication and generating additional audio data indicating a sound to be added to the sound indicated by the audio data;
the additional audio data is input to the first amplifier via the audio bus;
audio device. an audio device according to any one of claims 1 to 14;
an in-vehicle bus connected to each of the head unit and the first amplifier;
vehicle. a first communication circuit connected via an in-vehicle bus to a head unit that outputs audio data and control data;
a second communication circuit connected to the audio module via an audio bus capable of two-way communication by serial communication, and outputting the audio data and the control data using a communication protocol different from that of the in-vehicle bus; prepared,
controlling operation of the audio module based on the control data;
audio amplifier.

Images