JP2003174343A - Audio apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible for a user to listen to an audio signal (voice) continuously without having a sense of incongruity or annoyance on auditory sense and prevent heat run-away of a digital device like DSP for adding an acoustic effect. <P>SOLUTION: The audio apparatus 10 includes an amplifying unit 12 for generating an audio signal to a speaker 11, a digital processing unit 15 for adding an acoustic effect to the audio signal, a switching connection unit 13 for connecting the audio signal AD selectively to the digital processing unit 15 or to the amplifying unit 12, a control unit 20, and a temperature sensor 17 provided near to the amplifying unit 12. On the basis of the control from the control unit 20, the digital processing unit 15 carries out the digital adjustment for reducing gradually the acoustic effect as the temperature detected by the temperature sensor 17 increases, the switching connection unit 13 connects the audio signal AD to the amplifier when the detected temperature is over the prescribed ceiling limit. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio apparatus having a function of adding a sound effect, and particularly when adding a sound effect by a digital device such as a digital signal processor (DSP) having a relatively low heat resistance. , An audio device (for example, a vehicle-mounted audio device) adapted to eliminate the inconvenience caused by thermal runaway due to temperature rise of the digital device.

[0002]

2. Description of the Related Art In recent years, there has been a demand for higher performance and more multifunctional in-vehicle audio devices. Along with this, a two-way, three-way multi-speaker system in which a plurality of speakers having different reproduction bands are combined, and a speaker system including a sub woofer dedicated to heavy bass reproduction have been used. Then, in order to maximize the acoustic effect produced by such a speaker system, conventionally, a high-pass filter, a band-pass filter, a parametric equalizer and the like (hereinafter, simply referred to as “filter”) have been used. There is. Such a filter generally has a large circuit scale, and it has hitherto been considered difficult to incorporate it in a head unit of a vehicle audio device.

However, with the recent widespread use of digital signal processors (DSPs), it becomes possible to configure these filters in the DSP and set the filter coefficients by software, and also in the head unit of a vehicle audio device. These filters are being installed.

On the other hand, the in-vehicle audio device incorporates parts such as an amplifier for amplifying the audio signal supplied to the speaker. Then, an audio signal to which a sound effect is added by a DSP or the like is supplied to an analog audio circuit including components such as an amplifier. Since components such as amplifiers consume more power during operation than digital devices such as DSPs and microcomputers, they generally generate a large amount of heat accordingly.

Therefore, with respect to the temperature rise inside the audio device, the amount of heat generated exceeds that of the head unit including a digital device such as DSP, and it is assumed that the temperature guarantee upper limit (for example, 85 ° C.) of parts and the like is exceeded. In this case, the amount of heat generated is smaller than that of parts such as amplifiers (that is,
Digital devices such as DSPs and microcomputers (which have low heat resistance) may run into thermal runaway.

When a digital device causes a thermal runaway, its operation cannot be read. Therefore, for example, when the operation of the device becomes uncertain, the operation of the device or the operation of the audio circuit in the subsequent stage affected by the output thereof. May be indefinite. As a result, a loud sound may be output from the speaker in some cases, and in this case, there is an inconvenience that the user feels uncomfortable. In addition, the device itself may be damaged.

On the other hand, when the device is in an inoperable state, the acoustic effect that has been output up to that point suddenly becomes zero (0), which causes the user to feel uncomfortable. . In this case as well, the device itself may be damaged.

In order to cope with the inconvenience caused by such thermal runaway, in the conventional technique, when the operating temperature of a digital device such as a DSP which adds an acoustic effect exceeds a prescribed upper limit temperature, The so-called "shutdown control" is performed to stop the operation of the device.

[0009]

As described above, in the conventional technique, "shutdown control" is performed as a method for preventing the digital system (DSP, microcomputer, etc.) from running out of heat. In the method, since the digital system is operationally separated from the analog audio circuit, the sound related to the audio signal that can be heard until immediately before the shutdown control is performed,
There was the inconvenience that you could not continue listening.

In order to eliminate such inconvenience, it is conceivable, for example, to switch and connect an audio signal which has been input to the digital system up to that time to an analog audio circuit when performing the shutdown control of the digital system.

However, in this method, the audio signal (voice) to which the sound effect of the specified level is added is heard until immediately before the shutdown control is performed, but the sound effect is zero (0) after the shutdown control is performed. However, there is a problem in that the user feels uncomfortable or uncomfortable in hearing due to the sudden change in the acoustic effect.

The present invention has been made in view of the above problems in the prior art, and makes it possible to continuously listen to an audio signal (voice) without giving a user a feeling of discomfort or discomfort in hearing, and at the same time, sound It is an object of the present invention to provide an audio device capable of preventing a digital device such as a DSP, which has an effect, from causing thermal runaway.

[0013]

In order to solve the above-mentioned problems of the prior art, an audio apparatus according to the present invention includes an audio output amplification section for amplifying an audio signal and outputting the amplified audio signal to a speaker, and an audio output amplification section. An audio output digital processing unit that digitally adjusts the level and the signal delay time for at least each frequency band to add a sound effect to the supplied audio signal, and selectively selects the audio signal from the audio source. A switching connection unit that is switched to connect to the audio output digital processing unit or the audio output amplification unit, a control unit that controls the audio output digital processing unit and the switching connection unit, and is disposed near the audio output amplification unit. And a temperature sensor for controlling the audio output digital processing unit. Controls to perform gradual digital adjustment for reducing the sound effects with increasing temperature detected by said temperature sensor, to said switch connecting portion,
When the detected temperature exceeds a predetermined upper limit temperature, the audio signal from the audio source is controlled to be connected to the audio output amplifier.

According to the audio apparatus of the present invention, under the control of the control unit, the audio output digital processing unit performs digital adjustment on the audio signal to gradually reduce the acoustic effect as the detected temperature rises. As a result, the user who is listening to the voice related to the audio signal from the audio output digital processing unit via the audio output amplification unit and the speaker hardly feels the change in the voice.

Thus, when the audio signal input to the audio output digital processing unit (digital system) is switched and connected to the audio output amplification unit (analog system), the user feels uncomfortable or uncomfortable in hearing. The audio signal (sound) can be continuously listened to without being heard.

Further, when the detected temperature exceeds a predetermined upper limit temperature, the audio signal is switched and connected from the audio output digital processing section to the audio output amplification section by the switching connection section under the control of the control section. The audio output digital processing unit stops its operation. As a result, it is possible to prevent the audio output digital processing unit (digital system) from running out of heat, and it is possible to avoid the operation indefinite (or inoperable) state.

In the above audio device,
The control unit may control the audio output digital processing unit to perform digital adjustment such that the acoustic effect becomes zero when the detected temperature reaches the predetermined upper limit temperature.

With this control mode, the switching connection of the audio signal from the digital system to the analog system is performed after the acoustic effect added to the audio signal becomes zero, so that the switching connection is performed. There is no change in the acoustic effect between immediately before and immediately after. As a result, it is possible to continuously listen to the audio signal (voice) without giving the user any feeling of discomfort or discomfort.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a schematic configuration of an audio apparatus according to an embodiment of the present invention. The present embodiment shows an example in which the present invention is applied to a head unit of a vehicle audio device.

The audio device 10 according to the present embodiment is
The basic configuration includes a speaker 11, an audio output amplification unit 12, a switch 13, a digital signal processor (DSP) 15, a temperature sensor 17, and a microcomputer 20. Although not shown in particular for simplification of description, a plurality of speakers 11 are actually provided. For example, each speaker for the front seats provided on the left and right of the front side of the vehicle and the speaker for the rear side are provided. Each speaker is provided on the left and right for the rear seats, and a speaker (sub woofer) for reproducing deep bass sound is provided near the rear seats.

The audio output amplifying section 12 basically amplifies an analog audio signal input via the DSP 15 or an analog audio signal AD directly input by bypassing the DSP 15 to amplify the speaker 11.
It has the function of supplying to. Although not particularly shown, the audio output amplification unit 12 is a field effect transistor (FET) that performs output amplification of an audio signal to be supplied to each speaker according to the arrangement form (the number of installations) of the speaker 11. ), A plurality of drivers for driving the FET, a low-pass filter, and the like.

The switch 13 is the microcomputer 2
The switching operation is performed in response to the control signal CS1 supplied from 0, and the analog audio signal AD output from the audio source is selectively switched and connected to the audio output amplifier 12 or the DSP 15 side. The audio signal AD connected to the DSP 15 side by the switch 13 is supplied to the DSP 15 after being digitized via the interface (I / F) 14.

Like the audio output amplification section 12, the switch 13 also has a number of switches, which is not shown, depending on the arrangement form (the number of installations) of the speaker 11.

The DSP 15 performs various digital adjustments (level adjustment for each frequency band, adjustment of signal delay time, etc.) for adding a sound effect to the audio signal to be supplied to the audio output amplifier 12 in the subsequent stage. It has a function to do. The DSP 15 adjusts the level of the digital audio signal input via the interface 14 to a prescribed level based on the control signal CS2 from the microcomputer 20, and outputs the electronic volume 15a. Level for each frequency band of the output audio signal (band level)
Is adjusted in accordance with the filter coefficient uniquely set by the control signal CS3 from the microcomputer 20, and the signal output from the equalizer unit 15b is used as a control signal from the microcomputer 20. The signal delay unit 15c delays the signal for a predetermined time based on CS4. In addition, DS
The digital audio signal output from the signal delay unit 15c of P15 is analogized via the interface (I / F) 16 and then supplied to the audio output amplification unit 12.

Like the audio output amplifier 12, the DSP 15 is also not shown in the figure, but the number of functional blocks (electronic volume 15a, EQ 15b, signal delay unit) corresponding to the layout form (number of installed speakers) 11 is set. 15
c).

As described above, the audio signal AD output from the audio source is switched by the switch 13 under a predetermined condition as described later, and is sent to the audio output amplifier 12 via the interface 14, the DSP 15 and the interface 16. Supplied or DSP1
The signal is directly supplied to the audio output amplification unit 12 without going through 5 or the like (that is, bypassed).

On the other hand, the temperature sensor 17 is disposed (thermally coupled) in the vicinity of the FET (audio output amplifying section 12) that generates the most heat among the components of the apparatus 10. . For example, when the FET is molded in the form of a package and is disposed on the heat sink, the temperature sensor 17 is fixedly supported by a metal bracket on the heat sink in the vicinity of the component (FET). 17 and the component are thermally coupled to each other.

The signal (analog signal) detected by the temperature sensor 17 is amplified by the amplifier 18 to a level sufficient for the microcomputer 20 to perform predetermined digital processing, and then the interface (I / F) 19 is used. It is digitized through and supplied to the microcomputer 20. Note that the amplifier 18 at the subsequent stage of the temperature sensor 17 is not necessarily provided if the signal detected by the temperature sensor 17 has a sufficient level for the microcomputer 20.

The microcomputer 20 operates based on a preset program, and as will be described later, based on the temperature (data) detected by the temperature sensor 17, the operation of the DSP 15 (for adding an acoustic effect). In addition to performing processing for controlling (digital adjustment), the switching operation of the switch 13 is controlled.

Specifically, for the DSP 15, the temperature detected by the temperature sensor 17 is a predetermined upper limit temperature (for example,
Pre-set temperature lower than 84 ° C (eg 60 ° C)
When the temperature exceeds the limit, control is performed to start digital adjustment to reduce the acoustic effect, and thereafter, digital control is performed to gradually reduce the acoustic effect as the detected temperature rises. The control is performed so that the digital adjustment is performed so that the acoustic effect becomes zero when it reaches (control signals CS2 to CS4). Further, when the detected temperature once exceeding the predetermined upper limit temperature drops and falls below the upper limit temperature, the DSP 15 is controlled to start digital adjustment for gradually increasing the acoustic effect from zero (control signal CS2). ~ CS4).

On the other hand, with respect to the switch 13, when the temperature detected by the temperature sensor 17 exceeds the upper limit temperature, the connection of the audio signal AD to the DSP 15 side is cut off, and the audio output amplification section 12 of the audio signal AD concerned. The control is performed so as to perform the switching connection to (control signal CS1). On the contrary, when the detected temperature once exceeding the upper limit temperature drops and falls below the upper limit temperature, the switch 13 is disconnected from the audio output amplifying unit 12 to disconnect the audio signal AD. Control is performed so as to perform switching connection to the DSP 15 side (control signal CS1).

FIG. 2 shows the audio device 10 of this embodiment.
Sound effect (that is, the audio signal AD based on the cooperation of the DSP 15 and the microcomputer 20).
Is a list of functions related to sound effects added to. In the example shown in the figure, as a function to be an index of the acoustic effect, bass range (BASS KNOB) adjustment, gain (GAIN) adjustment, low pass (LP) frequency setting, sub-sound (SUB SONIC
) Frequency setting, parametric equalizer level (P
EQ LEVEL) settings and adjustments related to signal delay time correction (TCR) are included.

As shown in FIG. 2, for example, regarding gain adjustment, digital adjustment is performed so that “gain”, which is an index of acoustic effect, gradually decreases (or increases) as the detected temperature increases (or decreases). Is performed, and the digital adjustment is performed so that the gain becomes zero when the detected temperature reaches the upper limit temperature (84 ° C.).

Similarly for other functions, digital adjustment is performed so that the acoustic effect gradually decreases (or increases) as the detected temperature rises (or decreases), and the detected temperature reaches the upper limit temperature (84 ° C.). ) Is reached, digital adjustments are made so that the sound effect becomes zero.

Hereinafter, an example of the processing flow of the processing relating to the bypass of the DSP 15 (processing for gradually reducing the acoustic effect to zero and stopping the digital system) performed by the microcomputer 20 in the audio device 10 of the present embodiment Will be described with reference to FIG.

In the initial state, it is assumed that the audio signal AD from the audio source is supplied from the switch 13 to the audio output amplification section 12 via the interface 14, the DSP 15 and the interface 16. That is, the audio output amplification unit 12 to the speaker 1
It is assumed that the voice related to the audio signal to which the sound effect is added by the DSP 15 is being output through 1 through 1.

First, in step S11, the temperature sensor 17
The data instructing the temperature detected at is fetched through the amplifier 18 and the interface 19.

In the next step S12, it is determined whether the detected temperature is equal to or higher than a predetermined set temperature (for example, 60 ° C.) (YES) or not (NO) based on the temperature data taken in. If the determination result is YES, step S13
If the determination result is NO, the process flow is “end”.

At the next step S13, the DS is changed by the control signals CS2 to CS4 from the microcomputer 20.
Each functional block that constitutes P15 (electronic volume 15
The a, the EQ 15b, and the signal delay unit 15c) are controlled to change the respective function settings related to the digital adjustment for adding the acoustic effect.

That is, the DSP 15 is controlled to start digital adjustment for reducing the acoustic effect, and thereafter,
The acoustic effect is gradually reduced as the detected temperature rises, and digital adjustment is performed so that the acoustic effect becomes zero when the detected temperature reaches a predetermined upper limit temperature. here,
As described with reference to FIG. 2, for example, regarding the correction (TCR) of the signal delay time, the meaning of “decrease gradually” means that the signal delay of the signal delay unit 15c increases every time the detected temperature increases by 1 ° C. Time is 10ms, 9ms, 8ms, ...
It means a control mode that changes.

In the digital adjustment of the acoustic effect performed in this step, it has been described that the detected temperature continues to rise after the temperature exceeds the predetermined set temperature, but on the contrary, the detected temperature changes so as to decrease. In this case, control is performed so as to perform digital adjustment that gradually increases the acoustic effect as the detected temperature decreases.

In the next step S14, it is determined whether or not the detected temperature exceeds a predetermined upper limit temperature (for example, 84 ° C.) (YES) or (NO). If the determination result is YES, the process proceeds to step S15, and if the determination result is NO, the process returns to step S12 to repeat the above process.

In the next step S15, the DSP 15 is placed in a standby state under the control of the microcomputer 20.

That is, the control signal CS1 from the microcomputer 20 controls the switch 13 so as to perform the switching connection of the audio signal AD to the audio output amplification section 12 (that is, to bypass the DSP 15). As a result, the audio signal AD
Is disconnected from the DSP 15, the DSP 15 substantially stops its function (standby state).

At the final step S16, the microcomputer 20 itself stops its operation and enters the standby state.

Next, regarding the processing relating to the connection of the DSP 15 performed by the microcomputer 20 in the audio device 10 of the present embodiment (the processing of activating the digital system and gradually increasing the acoustic effect from zero), the processing flow will be described. This will be described with reference to FIG. 4, which shows an example.

In the initial state, the detected temperature exceeds the upper limit temperature (84 ° C.). That is, the DSP 15 is in the standby state together with the microcomputer 20, and the audio signal AD to which no acoustic effect is added is added.
Are supplied to the audio output amplifier 12 via the switch 13.

First, in step S21, the temperature sensor 17
The data instructing the temperature detected at is fetched through the amplifier 18 and the interface 19.

In the next step S22, the detected temperature is the upper limit temperature (84 ° C.) based on the temperature data taken in.
(YES) or not (NO). When the determination result is YES, the process proceeds to step S23, and when the determination result is NO, the process flow is “end”.

In the next step S23, the microcomputer 20 itself releases the standby state and resumes its operation.

In the next step S24, the standby state of the DSP 15 is released under the control of the microcomputer 20.

In other words, the control signal CS1 from the microcomputer 20 controls the switch 13 so as to switch and connect the audio signal AD to the DSP 15. As a result, the audio signal AD is supplied from the switch 13 to the DSP 15 via the interface 14, and the DSP 15 resumes its function.

In the next step S25, the DS is changed by the control signals CS2 to CS4 from the microcomputer 20.
Each functional block that constitutes P15 (electronic volume 15
The a, the EQ 15b, and the signal delay unit 15c) are controlled to change the respective function settings related to the digital adjustment for adding the acoustic effect.

That is, the DSP 15 is controlled to start digital adjustment for increasing the acoustic effect, and thereafter,
It is controlled to perform digital adjustment that gradually increases the acoustic effect from zero as the detected temperature decreases. Here, the meaning of "increase gradually" means that step S13 in FIG.
The control mode opposite to the "gradual reduction" control mode described in connection with.

In the digital adjustment of the acoustic effect performed in this step, it has been described that the detected temperature continues to decrease after the temperature falls below the predetermined upper limit temperature, but on the contrary, the detected temperature changes to increase. In this case, control is performed so as to perform digital adjustment that gradually reduces the acoustic effect as the detected temperature rises.

In the final step S26, it is determined whether the detected temperature is equal to or higher than the set temperature (60 ° C.) (YES) or not (NO). If the determination result is YES, step S2
Returning to 5, the above processing is repeated, and when the determination result is NO, this processing flow is “end”.

As described above, according to the audio device 10 of this embodiment, the microcomputer 20 controls the DSP 15 to increase the temperature detected by the temperature sensor 17, as shown in the processing flow of FIG. Control to perform digital adjustment to gradually reduce the acoustic effect,
When the detected temperature reaches the upper limit temperature (84 ° C), it is controlled so that the acoustic effect becomes zero, and the detected temperature of the switch 13 exceeds the upper limit temperature (84 ° C). At times, control is performed so that switching connection of the audio signal AD to the audio output amplification unit 12 is performed.

That is, the DSP 1 of the audio signal AD
The switching connection from 5 (digital system) to the audio output amplification unit 12 (analog system) is performed by the audio signal AD.
Since it is performed after the time when the acoustic effect added to 0 becomes zero, there is no change in the acoustic effect immediately before and after switching connection is performed. As a result, the user can continuously listen to the sound related to the audio signal AD without feeling uncomfortable or uncomfortable in hearing.

When the detected temperature exceeds the upper limit temperature (84 ° C.), the audio signal AD is changed to DSP1 by the switch 13 under the control of the microcomputer 20.
Since it is switched and connected to the audio output amplification unit 12 from the 5 side, the DSP 15 stops its operation, and the microcomputer 20 itself also stops its operation (standby state).

As a result, the digital system (DSP15,
It is possible to prevent thermal runaway of the microcomputer 20), and it is possible to avoid an indefinite / inoperable state due to thermal runaway.

On the other hand, as shown in the processing flow of FIG.
When the detected temperature is lower than the upper limit temperature (84 ° C.), the microcomputer 20 controls the switch 13 to switch and connect the audio signal AD to the DSP 15 side. It is controlled to perform digital adjustment that gradually increases the sound effect from zero as it decreases.

That is, since the audio output amplifier 12 (analog system) of the audio signal AD is switched and connected to the DSP 15 (digital system), digital adjustment is performed to gradually increase the acoustic effect from zero. ,
There is no change in sound effect immediately before and after switching connection. This makes it possible to continuously listen to the audio signal AD (speech) without giving the user any feeling of discomfort or discomfort.

[0064]

As described above, according to the present invention, the acoustic effect is gradually reduced as the temperature rises (or decreases) during the operation of a digital device such as a DSP that adds the acoustic effect to an audio signal. By making digital adjustment to increase or increase) and switching and connecting the audio signal to an analog audio circuit when the temperature exceeds a predetermined upper limit temperature, the user can hear the audio signal without feeling uncomfortable or uncomfortable. (Voice) can be continuously listened to, and at the same time, thermal runaway of a digital device such as a DSP can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a configuration of an audio device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a function (digital adjustment) related to a sound effect performed by the audio device in FIG.

FIG. 3 is a DS performed by the microcomputer shown in FIG.
FIG. 11 is a flowchart showing an example of a process relating to bypass of P (process of gradually reducing the acoustic effect to zero and stopping the digital system).

4 is a DS performed by the microcomputer shown in FIG.
It is a flowchart which shows an example of the process (process which starts a digital system and gradually increases a sound effect from zero) regarding connection of P.

[Explanation of symbols]

10 ... Audio device, 11 ... speaker, 12 ... Audio output amplifier, 13 ... switch (switch connection section), 15 ... DSP (audio output digital processing unit), 17 ... Temperature sensor, 20 ... Microcomputer (control unit), AD ... audio signal, CS1 to CS4 ... Control signals.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04R 3/00 101 H04R 3/00 101Z F term (reference) 3D020 BA02 BA10 BC01 BD03 BE03 5D020 AC01 AC10 5J030 AA01 AA10 AB01 AC00 AC01 AC08 AC11 AC16 AC20 5J092 AA02 AA41 CA00 CA02 FA18 HA09 HA26 HA38 HA43 KA15 KA33 KA42 KA62 MA20 SA05 TA01 TA07 VL08 5J500 AA02 AA41 AC00 AC02 AF18 AH09 AH26 AK15 AT62 AT20 AK15 AT62 AK33 AM20 AK33 AT20 AK33 AT20 AK33 AT20 AK33 AT20 AK33 AT20

Claims (7)

[Claims] 1. An audio output amplifier for amplifying an audio signal and outputting the amplified audio signal to a speaker, and level adjustment for at least each frequency band for adding a sound effect to the audio signal supplied to the audio output amplifier. An audio output digital processing section for digitally adjusting a signal delay time; a switching connection section for selectively switching an audio signal from an audio source to connect to the audio output digital processing section or the audio output amplification section; The audio output digital processing unit and a control unit for controlling the switching connection unit, and a temperature sensor arranged in the vicinity of the audio output amplification unit, the control unit, for the audio output digital processing unit, the temperature Digital that gradually reduces the acoustic effect as the temperature detected by the sensor rises And controlling the switching connection portion to connect the audio signal from the audio source to the audio output amplification portion when the detected temperature exceeds a predetermined upper limit temperature. An audio device characterized by. 2. The control unit controls the audio output digital processing unit to perform digital adjustment such that the acoustic effect becomes zero when the detected temperature reaches the predetermined upper limit temperature. The audio device according to claim 1, wherein the audio device is an audio device. 3. The control unit starts digital adjustment for the audio output digital processing unit to reduce the acoustic effect when the detected temperature exceeds a predetermined set temperature lower than the predetermined upper limit temperature. The audio device according to claim 2, wherein the audio device is controlled so as to operate. 4. The control unit, when the detected temperature once exceeding the predetermined upper limit temperature drops and falls below the upper limit temperature, sends the audio signal from the audio source to the switching connection unit. 3. The audio output digital processing unit is controlled to be connected, and the audio output digital processing unit is controlled to start digital adjustment for increasing the acoustic effect. Audio equipment. 5. The audio output digital processing section comprises:
The audio device according to claim 1, wherein the audio device is constituted by a digital signal processor. 6. The electronic signal processor adjusts the level of an audio signal input through the switching connection unit to a specified level and outputs the electronic volume, and the level of the audio signal adjusted through the electronic volume. An equalizer unit that adjusts the level of each frequency band according to a filter coefficient uniquely set by the control unit, and a signal output from the equalizer unit is delayed by a predetermined time based on the control from the control unit. 6. The audio apparatus according to claim 5, further comprising a signal delay unit that causes the audio signal to be delayed. 7. The audio device according to claim 1, wherein the audio device is mounted on a vehicle.