JP2872516B2 - Sound system equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio system device for connecting and operating a plurality of audio devices, and more particularly to an audio system device suitable for controlling a built-in volume circuit of the plurality of audio devices.

[0002]

2. Description of the Related Art Conventionally, an audio system device operated by connecting a plurality of audio devices is connected to an audio device such as an amplifier at a preceding stage for supplying a source signal and an audio device such as an amplifier at a final stage. The speaker system was connected to the audio equipment in the row.

As described above, each connected audio device is provided with a volume circuit (hereinafter, referred to as a VR circuit) for adjusting the volume and sound quality, or only the volume or only the sound quality, and adjusts the output level of each VR circuit. Alternatively, in the setting, the VR circuit is set to the maximum output level from the first stage to the last stage, and the volume level and the sound quality level of the speaker output are adjusted by the VR circuit of the last audio device of the audio system device.

That is, the VR of the audio equipment from the first stage to the last stage
The circuit eliminates the signal attenuation, and the input source signal is supplied to the final audio equipment at the input level as it is, so that the user using the audio system equipment can easily adjust the speaker output so that the VR circuit of the final audio equipment is used. The volume and sound quality of the speaker output were adjusted only by the speaker.

[0005]

However, when a plurality of the above-mentioned conventional audio system devices are connected, the VR circuits of the audio devices from the first stage to the last stage must be operated so as to be at the maximum output level. In addition, there is a problem that the operation of this VR circuit is troublesome, and when the audio system device is disconnected and the audio device is used alone, the setting VR value of the VR circuit of these audio devices is changed from the maximum level to the original VR value. It was necessary to readjust the volume level and sound quality level.

If the audio equipment is used alone without re-adjusting the VR circuit, the output of the speaker is at the maximum level.
Alternatively, there is a drawback in that the heat generated by the heat-generating components of the output circuit increases, which is dangerous.

When a plurality of audio devices are connected and operated as an audio system device, a connection point in the connection state of each audio device may be in an unconnected state due to, for example, vibration. When this happens, the output of the unconnected audio equipment at the preceding stage becomes the maximum output, which is dangerous.

When a speaker or the like is connected to the unconnected audio device, the output of the audio device reaches the maximum output level and is output to the speaker or the like. There was a disadvantage that it would.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to solve the disadvantages of the prior art, to detect connection or disconnection of an audio device, and to provide a built-in audio device.
It is an object of the present invention to provide an audio system device which automatically sets a VR value of a VR circuit to a predetermined setting level, facilitates adjustment of speaker audio output, and prevents damage or danger of a connected speaker.

[0010]

A sound system device according to the present invention is connected to a plurality of sound devices having a volume circuit for adjusting the volume and / or sound quality and operation keys for setting a volume value of the volume circuit. In a sound system device in which a source signal is supplied to a preceding sound device and sound is output from a speaker connected to the last sound device, connection detection means for detecting connection of the plurality of sound devices, and connection by the connection detection means Volume detection means for setting a volume circuit of an audio device connected to a preceding stage to a predetermined setting level at the time of detection, and a speaker output is adjusted by the volume circuit of the last audio device. .

A first audio device to which a source signal is supplied, a second audio device connected to an audio output terminal of the first audio device, and a speaker terminal of the second audio device. In an audio system device including a speaker, a level setting unit that sets a volume circuit of the first audio device to a maximum output level when connection between the first audio device and the second audio device is detected, The second
May be configured to adjust the speaker output by the volume circuit of the audio device.

[0012] Further, a first volume key for setting a volume value of the first audio device is provided, and a connection between the first audio device set by the first volume key and the second audio device is provided. Transfer means for transferring the volume value of the first audio device to the volume circuit of the second audio device at the time of detection is provided, the volume circuit of the first audio device is set to the maximum output level, and the data transfer is performed. Alternatively, a speaker circuit may be configured to be output by a volume circuit of the second audio device.

The second audio device is a third audio device, a microcomputer provided in the third audio device, a volume circuit, and a second circuit for setting a volume value of the volume circuit. An audio system device comprising a volume key and connecting the third audio device and the first audio device, wherein when detecting the connection between the first audio device and the third audio device, First
Storage means for storing the volume value of the audio device in the internal memory, and setting the volume circuit of the first audio device to the maximum output level, and setting the volume value of the third audio device set by the second volume key. There may be provided a return circuit for outputting a speaker by the volume circuit and returning the stored volume value to the volume circuit of the first audio device when disconnection of the third audio device is detected.

[0014]

The operation of the present invention will be described with reference to the functional block diagram shown in FIG. According to the present invention, the first-stage audio equipment (referred to as audio equipment A) at the previous stage to which the source signal is supplied and the second audio equipment (audio equipment B) at the final stage for performing speaker output
), And the connection time or the connection state can be detected by a built-in microcomputer (connection detection means 1). This connection detection detects, for example, that the audio device B is connected even when the power is turned on with the audio device B connected from the previous day.

That is, the microcomputer of the audio equipment A controls the operation of the switching unit for switching the connection inside the audio equipment B,
It can be detected by the operation of the switching unit. When the microcomputer detects the connection of the audio device B, the microcomputer sets the VR value by controlling the output of the VR circuit of the audio device A to a preset output level, for example, a maximum output level (maximum level setting means). 5).

The source signal output at the maximum output level is supplied to the audio equipment B, and the speaker output level can be determined by adjusting only the volume circuit of the audio equipment B.

If the connection at the moment when the audio device A and the audio device B are connected is not detected, that is, whether the audio device A and the audio device B are already connected or not connected is determined. If the first volume key (hereinafter, referred to as the first VR key) for setting the VR value of the VR circuit provided in the audio device A is operated, the VR stored in the microcomputer is stored. Reads the value and the current VR
The VR value of the circuit is up / down controlled to set the VR value by operating the first VR key (volume value setting means 2).

As described above, when the content of the VR value of the audio device A changes due to the first VR key, or when the audio device B detects that the audio device A is disconnected from the audio device A, the connection is detected. (Detection means 6 when not connected), the microcomputer is the audio device A
It is determined that the data setting process is valid for the VR value of the VR circuit of (1), and it is detected whether or not the audio device A and the audio device B are connected (during-connection detection means 3).

When it is detected that the audio equipment A and the audio equipment B are connected, the setting data of the VR circuit of the audio equipment A is transferred to the VR circuit of the audio equipment B via a microcomputer (transfer means). 4) The VR circuit of the audio device A to which the data has been transferred is set to the maximum output level in the same manner as described above (maximum level setting means 5).

That is, the VR circuit of the audio device B to which the data is transferred becomes equal to the VR value set by the first VR key,
The source signal level supplied from the audio device A to the audio device B becomes the maximum output level of the VR circuit of the audio device A, and the supplied signal level becomes the reference source signal level of the audio device B and becomes the level of the VR circuit of the audio device B. Sound is output from the speaker at the set output level.

On the other hand, when the connection of the audio equipment B is detected by detecting the connection of the audio equipment B (detecting means 3 during connection), the microcomputer comprises only the audio equipment A as the audio system equipment. Is determined, and the VR circuit of the audio device A is set to the VR value by the first VR key previously set by operating the VR circuit of the audio device A (VR value setting means 7). Output as VR value.

As described above, the detection function for detecting the connection between the audio equipment A and the audio equipment B, the function for taking in the operation data of the first VR key, or the detection of the disconnection between the audio equipment A and the audio equipment B Acoustic system equipment that has a detection function that can automatically adjust the speaker output only with the VR circuit of audio equipment B by setting the VR circuit of audio equipment A to the maximum output level when audio equipment A and B are connected. In addition, the speaker output of the sound system device can be easily adjusted.

When the audio device B is detected as not being connected (disconnection detecting means 6), the VR circuit of the audio device A automatically changes the maximum output level to the VR value set by the first VR key or the like. When the audio device A is set (volume value setting means 7) and the audio device A is not connected, it outputs a signal at the maximum output level, thereby preventing the conventional trouble from occurring.

As an application of the present invention, FIG. 4 shows an acoustic system device in which the acoustic device A is connected to another third acoustic device (referred to as an acoustic device C) having a microcomputer and operation keys. The operation of the present invention will be described with reference to the functional block diagram shown.

The built-in microcomputer of the audio device A and the microcomputer built in the audio device C are connected by a data line, and the audio device C has operation keys for setting a VR value of a VR circuit,
A second volume key (hereinafter, referred to as a second VR key) is provided, and a source signal from the audio device A is supplied to a speaker via a VR circuit of the audio device C.

When the audio system device thus configured detects the connection between the audio device A and the audio device C, that is, the connection including the connection at the moment of connection (connection detection means 20),
The VR value set in the VR circuit of the audio device A is stored in a storage unit inside the microcomputer, for example, a RAM (the storage unit 2).
1).

On the other hand, when the unconnected state of the audio equipment A and the audio equipment C, that is, the unconnected state at the moment when the connection is released is detected (unconnected state detecting means 25), the RAN inside the microcomputer is detected.
The VR value stored in the audio device A is returned to the VR circuit of the audio device A (return means 26), and the VR value of the VR circuit of the audio device A can be set (VR value setting device 22 of the audio device A).

When the second VR key is operated, the operation data is sent from the microcomputer of the audio device C to the VR circuit of the audio device C, and the VR value of the current VR circuit is up / down controlled.
The VR value of the VR circuit can be set by operating the second VR key (VR value setting means 23 of audio equipment C).

As described above, when the audio equipment C30 sets the VR value of the VR circuit by the second VR key, the microcomputer of the audio equipment C transmits data from the microcomputer of the audio equipment C to the microcomputer of the audio equipment A by operating the second VR key. The connection information between the audio equipment A and the audio equipment C is transmitted via the line, and the output of the VR circuit of the audio equipment A is set to the maximum output level (maximum output level setting means 24). Sound can be output with the VR value of the VR circuit of the audio device C set by the second VR key.

As described above, even when the connected audio devices A and C are both equipped with the microcomputer or the operation keys, the connection state is detected and the VR circuit of the preceding audio device A is automatically output to the maximum level in the same manner as described above. Level, and the speaker output can be performed at the set level of the VR circuit of the audio device C at the last stage. When the microcomputer of the audio device A detects the unconnected state, the VR circuit of the audio device A set to the maximum output level can be automatically reset to the original VR value. Can be prevented beforehand.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an audio system device according to the present invention will be described with reference to FIGS. FIG. 1 is a functional block diagram showing the operational configuration of the present invention, FIG. 2 is a block diagram of hardware, and FIG. 3 is a flowchart explaining the operation. FIG. 4 is a functional block diagram showing an operational configuration showing an embodiment to which the present invention is applied.
Is a block diagram of hardware of an application example, and FIG. 6 is a flowchart illustrating an operation of the application example.

In FIG. 2, reference numeral 10 denotes a source device of the audio system device, and a source signal from the source device 10 is a first audio device constituting the audio system device, ie, a first audio device.
It is supplied to the audio equipment A11. The circuit configuration of the main part of the audio equipment A11 includes a VR circuit 12, a microcomputer 13 (hereinafter referred to as a microcomputer 13) for controlling the VR circuit 12, and operation keys for instructing the microcomputer 13, as shown in the figure. A first volume key 14 for setting a volume value (hereinafter referred to as a VR value) of the VR circuit 12 is configured as the operation key.
(Hereinafter referred to as VR key 14).

Reference numeral 15 denotes a second audio device, that is, an audio device B. The circuit configuration of the main part of the audio device B15 has a VR circuit 16 and a switch for setting the connection of the VR circuit 16 as shown in the figure. Part 17
The operations of the VR circuit 16 and the switching unit 17 are controlled by a microcomputer 13 built in the audio device A11.
Reference numeral 18 denotes a speaker connected to the audio equipment B15.

As is well known, the microcomputer 13 is basically
It is composed of CPU, ROM, RAM, input port and output port (not shown). The ROM has a program to control the CPU written on it. Calculation processing is performed while fetching external data or transmitting / receiving data to / from the RAM, and processing data is output to the VR circuit 12 or the audio equipment B from an output port as necessary.

The acoustic system device thus configured is used, for example, when a portable CD player is connected to a stationary stereo set and a reproduction signal from the CD player is output from a speaker system of the stationary stereo set. The above CD
A reproduction signal of a CD disk from a disk reproduction unit (source device 10) of the player is supplied to a stationary stereo set (audio device B15) via an amplification output circuit (including the VR circuit 12 of the audio device A11) of the CD player. You.

That is, an audio device A11 (CD player) to which a source signal of the source device 10 is supplied and an audio device B15 (stationary stereo set) for outputting a speaker are connected.
The VR circuit 16 of the audio device B15 is connected by the switching operation of the switching unit 17.

When the switching section 17 is set to the contact a by the microcomputer 13 built in the audio equipment A11, the source signal from the audio equipment A11 is output to the speaker 18 via the VR circuit 16 of the audio equipment B15, and the switching is performed. When the unit 17 is set to the contact b, the source signal from the audio device A11 is directly supplied to the speaker 18.

As described above, the setting level of the VR value of each of the VR circuits 12 and 16 when the audio equipment A11 and the audio equipment B15 are connected or disconnected is determined by detecting the connection state by the microcomputer 13 of the audio equipment A11. Each of the VR circuits 12, 16
Will be described with reference to the flowchart of FIG.

When the switching unit 17 is controlled by operating an operation key or the like so as to connect the audio device A11 to the audio device B15, the microcomputer 13 detects the connection between the audio device A11 and the audio device B15 (step S1). The microcomputer 13 sets the VR value of the VR circuit 12 by controlling the output of the VR circuit 12 of the audio device A11 to the maximum output level (step S2).

The connection of the audio device B15 is also detected at the moment when the audio device B15 is connected to the audio device A11. Therefore, even when the audio system device is powered on with the connection from the previous day, for example, the connection is established. Detect that

As described above, when the output of the source signal of the audio equipment A11 is automatically output at the maximum output level of the VR circuit 12, this output source signal is supplied to the audio equipment B15 and Only the VR value setting level by VR value adjustment can be output as sound from the speaker 18.

Further, the audio equipment A11 and the audio equipment B
If the connection at the moment of connection with the audio device 15 is not detected (step S1), that is, if it is unknown whether the audio device A11 and the audio device B15 are already connected or not, it is provided in the audio device A11. When the first VR key 14 for setting the VR value of the VR circuit 12 is operated (step S3), the VR value stored in the RAM inside the microcomputer 13 is read and the current VR circuit is read.
The set VR value of 12 is up / down controlled (step S4), and the VR value of the VR circuit 12 is set based on the operation data of the first VR key 14.

When the first VR key 14 is not operated and the audio device B15 is disconnected from the audio device A11,
The microcomputer 13 detects this non-connection time (step S5), and the microcomputer 13 determines that it is effective to perform the data setting process on the VR value of the VR circuit 12 of the audio device A11, and again executes the audio device A11. It is detected whether or not the audio device B15 is connected to the audio device B15 (step S6).

When the microcomputer 13 detects that the audio device A11 and the audio device B15 are in a connected state, the setting data currently set in the VR circuit 12 of the audio device A11 is transferred to the VR circuit 16 of the audio device B15. Then, the data is transferred via the microcomputer 13 (step S7), and the output of the VR circuit 12 of the audio device A11 after the data transfer is set to the maximum output level (step S8).

That is, the audio device B15 to which the data has been transferred.
Of the VR circuit 16 of the audio device A11 becomes equal to the VR value set by the first VR key 14, and the source signal level supplied from the audio device A11 becomes the maximum output level of the VR circuit 12 of the audio device A11. The maximum supply signal level of the VR circuit 12 becomes the input reference source signal level of the audio equipment B11, and is output to the speaker 18 at the set output level of the VR circuit 16 of the audio equipment B15.

On the other hand, when the connection of the audio device B15 is detected to detect that the audio device B15 is not connected (step S6), the microcomputer 13 determines that the audio system device is composed only of the audio device A11. Then, the audio device A is set with the VR value by the first VR key 14 previously set by operating the VR circuit 12 of the audio device A11 (step S9).
The source signal input to 11 is the VR circuit 12 of the audio device A11.
Is output from the speaker 18 via the switching unit 17 of the audio equipment B15 at the VR value of.

As described above, the microcomputer 13 of the audio device A11
Detects the connection between the audio device A11 and the audio device B15,
Alternatively, the VR value of the VR circuit 12 of the audio device A11 is reset with the operation data of the first VR key 14 of the audio device A11, or the disconnection between the audio device A11 and the audio device B15 is detected,
When the audio equipment A, B 11, 15 is connected, the audio equipment A11 is automatically
Set the VR circuit 12 of the audio equipment B15 to the maximum output level.
The sound output of the speaker 18 can be adjusted only by the set VR value of the VR circuit 16.

When the audio device B15 is not connected, the VR circuit 12 of the audio device A11 automatically sets the VR value set by the first VR key 14 or the like from the previously set maximum output level. Fix audio equipment A11 when audio equipment B15 is not connected
Thus, it is possible to prevent the speaker 18 from being damaged due to the maximum output level from the loudspeaker or the danger from being generated due to the heat generated by the heat-generating components.

As an application of the present invention, an embodiment of an audio system device in which the above-mentioned audio device A11 is connected to another audio device C having a microcomputer and operation keys is shown in FIG. The operation will be described with reference to the flowchart of FIG.

In FIG. 5, reference numeral 30 denotes an audio equipment C. The circuit configuration of a main part of the audio equipment C 30 is a VR circuit as shown in FIG.
31, a microcomputer 32 for controlling the VR circuit 31, and an operation key for instructing the microcomputer 32. The operation key includes a second VR key 33 for instructing a setting level of the VR circuit 31.
Is installed.

In the acoustic system device thus configured, the acoustic device A11 and the acoustic device C30 for outputting a speaker are connected, and the microcomputer 32 of the acoustic device C30 is connected to the microcomputer 13 built in the acoustic device A11 by a data line. ing.

That is, the microcomputer 13 built in the audio device A11
And the microcomputer 32 built in the audio device C30 can perform data transfer, for example, execute data transfer of VR value setting of the VR circuits 12 and 32 controlled by the microcomputers 13 and 31 and connection control of the device. can do. As described above, each VR when the audio device A11 and the audio device C30 are connected or not connected is set.
The VR value setting operation of the circuits 12, 31 will be described with reference to the flowchart of FIG.

When the audio device A11 and the audio device C30 are connected, the source signal from the source device 10 is supplied to the VR circuit 31 of the audio device C30 via the VR circuit 12 of the audio device A11. The output source signal of the VR circuit 31 is the speaker 18
More sound output.

The connection between the audio device A11 and the audio device C30, that is, the connection including the connection at the moment of connection is detected by the microcomputer 32, and this connection information is sent to the microcomputer 13 of the audio device A11. (Step S10).

As described above, the acoustic device A11 is the acoustic device C
When the connection state of the audio device A11 is detected, the microcomputer 13 of the audio device A11 is detected.
Represents the VR value data X set in the VR circuit 12 by the microcomputer 13
Is stored in the internal RAM as storage data Y (step
S11).

On the other hand, when the acoustic device A11 is not connected to the acoustic device C30, that is, when the acoustic device C30 is disconnected (for example, when the acoustic device C30 is detached from the acoustic device A11), the microcomputer is connected.
When the microcomputer 13 detects from the transfer information from the microcomputer 32 (step S12), the microcomputer 13 reads out the VR value data Y previously stored in the internal RAM and transfers it to the VR circuit 12, and
The audio device A is restored as the VR value X of 12 (step S13).
The VR value X of the 11 VR circuits 12 can be set.

When the second VR key 33 provided on the audio device C30 is operated in a state where the VR value X of the VR circuit 12 of the audio device A11 is set (step S1), the operation data is stored in the audio device A11. The operation data of the B-VR key 33 is sent to the microcomputer 32 of the C30, and the UP / DOWN control is performed on the current VR value set in the VR circuit 31 (step S15). VR value Z can be set (step S1).
6).

That is, the VR circuit 16 of the audio equipment C30 is a B-VR key
An arbitrary VR value Z is set by the operation of 33,
By operating the VR key 33, the microcomputer 13 detects a connection state in which the audio device C30 is connected to the audio device A11.
By controlling the 11 VR circuits 12, control is performed so that the set VR value X of the VR circuit 12 becomes the maximum output level.

As described above, when the audio equipments A11 and C30 are in the connection state, the source signal input to the audio equipment A11 has the maximum output level automatically set by the VR circuit 12 and the audio equipment C11 has the maximum output level.
The audio device C30 is supplied to the VR circuit 16 and the second VR
Sound can be output from the speaker 18 at the output level set by the key 33.

When the unconnected state is detected, the VR circuit 12 of the audio device A11 set to the maximum output level can be automatically returned to the original VR value X of the VR circuit 12 and set. Problems at the time of non-connection can be prevented beforehand.

As described above, in the embodiment and the application example, the setting control of each VR circuit 12, 16 or 32 when the two audio devices A11 and B15 or the audio devices A11 and C30 are connected or not connected has been described. Even when two or more audio devices are connected, the same audio device can be implemented using the same control function of each VR circuit.

[0062]

As described above, the audio system device according to the present invention automatically sets the VR circuits of the preceding plurality of audio devices to the maximum output level when the plurality of audio devices are connected, and sets Since the speaker output can be adjusted only by the VR circuit of the audio device, there is an effect that the volume control and the sound quality of the audio system device can be easily adjusted.

Further, when not connected, the VR circuits of a plurality of preceding audio devices are automatically reset to the original VR value, so that the signal output at the maximum output level when not connected is avoided, and This has the effect of preventing damage to the connected speakers and danger due to heat-generating components.

Further, the VR circuit setting function for automatically setting the VR value of the built-in VR circuit when the audio device is connected or not connected largely depends on the software of the built-in microcomputer, and raises the cost. It has an advantage that the function of the audio equipment can be improved without any problem, and has excellent features such as easy implementation.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an operational configuration of an audio system device according to the present invention.

FIG. 2 is a hardware block diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart illustrating the operation of the embodiment of the present invention.

FIG. 4 is a functional block diagram showing an operational configuration of another application example of the present invention.

FIG. 5 is a block diagram of hardware showing an application example of the present invention.

FIG. 6 is a flowchart illustrating an operation of an application example of the present invention.

[Explanation of symbols]

 10 Source equipment 11 Audio equipment A 12 Volume (VR) circuit 13 Microcomputer (microcomputer) 14 First volume (VR) key 15 Audio equipment B 16 Volume (VR) circuit 17 Switching unit 18 Speaker 30 Audio equipment C 31 Volume ( VR) circuit 32 Microcomputer (microcomputer) 33 Second volume (VR) key

Claims (4)

(57) [Claims] 1. A plurality of audio devices each having a volume circuit for adjusting volume and / or sound quality and operation keys for setting a volume value of the volume circuit are connected, and a source signal is supplied to a preceding audio device. In an audio system device that outputs sound from a speaker connected to the last audio device, connection detection means for detecting connection of the plurality of audio devices,
Volume setting means for setting the volume circuit of the audio device connected to the preceding stage to a predetermined setting level when the connection is detected by the connection detecting device, and adjusting the speaker output by the volume circuit of the last audio device An acoustic system device characterized by having such a configuration. 2. A first audio device to which a source signal is supplied, and a second audio device connected to an audio output terminal of the first audio device.
And a speaker connected to the speaker terminal of the second audio device, wherein the first audio device detects the connection between the first audio device and the second audio device. 2. The sound system device according to claim 1, further comprising a level setting means for setting a volume circuit of the device to a maximum output level, wherein a speaker output is adjusted by the volume circuit of the second sound device. 3. A first volume key for setting a volume value of the first audio device, wherein the first volume key is set by the first volume key and the second volume key is set by the first volume key.
Transfer means for transferring the volume value of the first audio device to the volume circuit of the second audio device when connection with the audio device is detected, and setting the volume circuit of the first audio device to the maximum output level 3. The audio system device according to claim 2, wherein a speaker circuit is output by a volume circuit of the second audio device to which the data is transferred. 4. The second audio device is a third audio device, a microcomputer provided in the third audio device, a volume circuit, and a second circuit for setting a volume value of the volume circuit. An audio system device comprising a volume key and connecting the third audio device and the first audio device, wherein when detecting a connection between the first audio device and the third audio device, Storage means for storing a volume value of the first audio device in an internal memory; a volume circuit of the first audio device set to a maximum output level; and the third audio set by the second volume key Return means for outputting a speaker in a volume circuit of the device and returning the stored volume value to the volume circuit of the first audio device when disconnection of the third audio device is detected; Acoustic system equipment according to claim 2, characterized in that provided.