JPH11284463A - Acoustic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high sound quality by preventing saturation at the time of high volume input, while minimizing the degradation of accuracy in arithmetic operations in a digital signal processor, such as a DSP for digital signal processing. SOLUTION: An A/D converter 3 converts an analog audio signal from an LPF 2 into a digital signal, while a digital signal processor 4 generates audio signal level data from that signal and outputs them to a control part 9, and volume control as an internal processing of the digital signal processor 4 is performed by a volume control signal from the control part 9, and the audio signal after undergoing the volume control is converted to an analog signal by a D/A converter 5, passed through an LPF 6 and a power amplifier 7, and outputted from a loudspeaker 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio device for controlling a sound field by digital signal processing such as a DSP.

[0002]

2. Description of the Related Art Conventionally, there has been known an acoustic device having a function of adjusting and controlling a volume level using digital signal processing.

[0003]

However, in the conventional adjustment and control of each sound volume level using digital signal processing, a manual operation is performed by a user's operation, or an arithmetic processing setting in which an input sound volume level is predicted in advance is performed. It has to be performed, and the level cannot be automatically adjusted according to the input level of each music source and the control amount of the glyco.

[0004] The present invention solves the above-mentioned problems in the prior art, and automatically adjusts the level according to the input level of each music source and the amount of control of the glyco, thereby performing an operation by digital signal processing. It is an object of the present invention to provide an excellent acoustic device that achieves high sound quality while minimizing deterioration of accuracy and preventing saturation when a large volume is input.

[0005]

In order to solve the above-mentioned problems, an audio apparatus according to the present invention generates volume level data by a digital signal processing device such as a DSP and outputs the data to a control unit. Based on the volume level data and the volume level control signal generated by the glyco control amount,
In the internal processing of the digital signal processing device, volume level control based on a volume level control signal is performed.

Thus, in an audio apparatus such as a DSP which performs sound field control by digital signal processing, compared to the conventional method, the user can manually operate the apparatus or set the arithmetic processing in which the input volume level is predicted in advance. There is no need to perform this operation, and an excellent sound device capable of controlling the sound volume level in the internal processing of the digital signal processing device according to the sound volume level of the music to be reproduced and the amount of glyco control is obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an A / D converter for converting an analog audio signal from a music source into a digital signal, and a digital audio signal from the A / D converter. In addition to generating and outputting the level data to the control unit, the volume level control based on the level control signal is performed in the internal processing of the digital signal processing device by the volume level control signal from the control unit and the level control amount of the glyco. A digital signal processing device, and a volume level control signal generated from level data from the digital signal processing device, the volume level control signal is output to the digital signal processing device again, and a level control of a glyco in accordance with a user operation. A control unit that outputs a signal, and converts an audio signal from the digital signal processing device into an analog signal And a D / A converter for controlling the volume level of the music to be reproduced and the volume level in accordance with the control amount of the glyco. This has an effect that high sound quality can be realized by minimizing deterioration and preventing saturation when a large volume is input.

According to a second aspect of the present invention, when the control unit receives data having a volume level higher than the reference value from the digital signal processing device and the volume amplification level controlled by the glyco is high, 2. The sound device according to claim 1, wherein the sound level control signal is generated so as to lower the sound volume level calculated inside the signal processing.
This has the effect of minimizing the deterioration of the calculation accuracy due to digital signal processing and preventing saturation when a large volume is input, thereby realizing high sound quality.

According to a third aspect of the present invention, when the control unit receives data having a volume level lower than the reference value from the digital signal processing device and the volume attenuation level controlled by the glyco is large, 2. The acoustic device according to claim 1, wherein a volume level control signal is generated so as to increase a volume level calculated inside the signal processing, wherein deterioration of the calculation accuracy due to digital signal processing is minimized, and There is an effect that high sound quality can be realized by preventing saturation when a large volume is input.

Next, embodiments of the present invention will be described in detail with reference to the drawings. (Embodiment) FIG. 1 is a block diagram showing a configuration of an audio apparatus according to an embodiment of the present invention, which is used for an acoustic effect such as car audio.
In FIG. 1, reference numeral 1 denotes a music source playback device for playing back a music signal stored in an audio storage medium such as a CD as an audio signal, and 2 denotes a low-pass filter (LPF) for performing a filtering process on the audio signal from the music source playback device 1. 3 is LP
An A / D converter 4 converts an analog audio signal from F2 into a digital signal, and 4 generates audio signal level data from the digital audio signal from A / D converter 3 to control unit 9
And the sound level control signal generated from the control unit 9 and the volume control signal generated based on the amount of the glyco control, performs the volume level control in the internal processing of the digital signal processing device 4, and performs the audio level control. A digital signal processor for outputting a signal to a D / A converter 5, a D / A converter 5 for converting a digital audio signal from the digital signal processor 4 into an analog signal, and a digital signal processor 6 for outputting a signal from the D / A converter 5. A low-pass filter (LPF) for filtering an audio signal; 7 a power amplifier for amplifying the audio signal from the LPF 6; 8 a speaker for outputting the audio signal from the power amplifier 7 as a music signal; 9 a digital signal processing device 4 from the audio signal level data and the glyco level control signal corresponding to the user operation. Generates a sound volume level control signal for performing sound volume level control in the internal processing of the digital signal processing unit 4, and outputs to the digital signal processing unit 4, a control input signal from the operation unit 10, display unit 11
A control unit 10 configured by a microcomputer or the like that performs processing such as output control of display data to the control unit 10 that outputs a control signal in response to a user operation;
Reference numeral 11 denotes an LCD for displaying display data from the control unit 9.
And the like.

Next, the operation of this embodiment will be described. In FIG. 1, the music source is a music source playback device 1
And outputs the music signal to the LPF 2. LPF2
Performs a filtering process on the music signal from the music source reproducing apparatus 1 and outputs the filtered signal to the A / D converter 3. A / D converter 3
Converts the music signal from the LPF 2 into a digital signal and outputs the digital signal to the digital signal processing device 4. The digital signal processing device 4 generates audio signal level data from the digital audio signal from the A / D converter 3 and outputs it to the control unit 9. The control unit 9 controls the digital signal processing device 4
A volume level control signal in the internal processing of the digital signal processing device 4 is generated from the audio signal level data supplied from the CPU and the level control signal of the glyco in accordance with the operation of the user, and is output to the digital signal processing device 4. The digital signal processing device 4 performs a volume level control based on the volume level control signal in the internal processing of the digital signal processing device 4 in accordance with the volume level control signal from the control unit 9, and performs the audio signal after the volume level control. To D
/ A converter 5. The D / A converter 5 converts the audio signal from the digital signal processor 4 into an analog signal,
Output to PF6. The LPF 6 filters the music signal from the D / A converter 5 and outputs the music signal to the power amplifier 7. The power amplifier 7 amplifies the audio signal from the LPF 6 and outputs it to the speaker 8. The speaker 8 outputs a sound signal from the power amplifier 7 as sound. The control unit 9
Control of an input signal from the operation unit 10 and output control of a volume level adjustment value (control level) to the display unit 11 are performed. The operation unit 10 outputs a control signal for a user operation such as a glyco control to the control unit 9. The display unit 11
The display data from the control unit 9 is displayed.

FIG. 2 is a functional block diagram of a device for generating audio signal level data in the digital signal processing device 4. In FIG. 2, the digital audio signal from the A / D converter 3 is supplied to a frequency component dividing device 41.
The frequency component dividing device 41 is constituted by a digital filter that allows only a designated frequency component to pass, and passes the digital audio signal only to a designated frequency component and outputs the digital audio signal to an absolute value calculating device 42. The absolute value calculation device 42 performs an absolute value process on the digital audio signal passed from the frequency component division device 41, converts the digital audio signal into a signal having only a level component, and outputs the signal to the peak hold device 43. The peak hold device 43 detects and stores peak hold data of the audio signal subjected to the absolute value processing for a certain period of time, and outputs the data to the output control device 44. The output control device 44 outputs the peak-held volume level data in response to a data request from the control unit 9. The control unit 9 can acquire the peak hold level based on the data from the output control device 44.

FIG. 3 is a functional block diagram of a device for performing audio level control and glyco control in the digital signal processing device 4. In FIG. 3, the audio signal level data from the digital signal processing device 4 from the control unit 9 and the volume level control signal generated from the level control signal of the glyco in accordance with the operation of the user are transmitted to the audio level control device 49.
And a glyco control signal is supplied to the glyco 46. The audio level control device 49 adjusts the levels of the preceding level control device 45 and the subsequent level control device 48 based on the volume level control signal from the control section 9. The level controller 45 at the preceding stage converts the digital audio signal from the A / D converter 3 into the audio level controller 49.
And outputs it to the glyco 46. The glyco 46 performs a glyco signal processing intended by the audio device, and outputs the processed glyco signal to the volume control device 47. The volume control device 47 controls the volume according to the purpose of the user, and outputs it to the subsequent level control device 48. The latter level control device 48 controls the audio signal from the volume control device 47 in accordance with the audio level control device 49 and outputs the signal to the D / A converter 5 so that the level can be adjusted. Further, the glyco 46 performs gain adjustment processing for each frequency according to the glyco control signal.

FIG. 4 is a flowchart showing the processing in the control unit 9. 4, the control unit 9 compares the audio signal level data from the digital signal processing device 4 with a reference value already stored in the control unit 9 (S1), and stores the comparison result (A). If the level data is larger than the reference value, the MAX value (B) of the glyco control signal of each frequency to be output to the digital signal processing device 4 is stored (S2).

(Processing in FIG. 4) When the MAX value (B) of the glyco control level is set in a direction to attenuate the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are set. The sum is calculated (S3), and if the calculation result is set in the attenuating direction, the sound level of the music source is increased to a value at which the sound signal of the music source is not saturated inside the digital signal processing, and arithmetic processing is performed (S4). A control signal is transmitted (S10).

(Processing of FIG. 4) When the MAX value (B) of the glyco control level is set in the direction to amplify the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are set. The sum is calculated (S3), and if the calculation result is set to be amplified, the audio level is lowered to a value at which the audio signal of the music source is not saturated inside the digital signal processing, and arithmetic processing is performed (S5). A control signal is transmitted (S10).

(Processing in FIG. 4) When the MAX value (B) of the glyco control level is set in a direction to amplify the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are set. The audio level is reduced to a value at which the audio signal does not saturate inside the digital signal processing, the arithmetic processing is performed by lowering the audio level (S5), and the control signal is transmitted (S1).
0).

In FIG. 4, the control unit 9 compares the audio signal level data from the digital signal processing device 4 with a reference value already stored in the control unit 9 (S1).
The comparison result (A) is stored. If the level data is smaller than the reference value, the MAX value (B) of the glyco control signal of each frequency to be output to the digital signal processing device 4 is stored (S6).

(Processing in FIG. 4) When the MAX value (B) of the glyco control level is set in a direction to attenuate the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are set. The audio level is increased to a value at which the audio signal does not saturate inside the digital signal processing, arithmetic processing is performed (S7), and a control signal is transmitted (S1).
0).

(Processing in FIG. 4) When the MAX value (B) of the glyco control level is set in the direction of amplifying the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are set. The sum is calculated (S8), and if the calculation result is set in the attenuating direction, the sound level of the music source is increased to a value at which the sound signal of the music source is not saturated inside the digital signal processing, and arithmetic processing is performed (S7). A control signal is transmitted (S10).

(Processing in FIG. 4) When the MAX value (B) of the glyco control level is set in a direction to amplify the audio signal of the music source, the comparison result (A) and the MAX value (B) of the glyco control level are obtained. The sum is calculated (S8), and if the calculation result is set to be amplified, the sound level of the music source is reduced to a value at which the sound signal of the music source is not saturated inside the digital signal processing, and arithmetic processing is performed (S9). A control signal is transmitted (S10).

FIG. 5 is a flowchart showing the processing of the digital signal processing device 4. In FIG. 5, the digital signal processing device 4 acquires a level control signal from the control unit 9 (S11), and checks what the content is (S1).
2). The level control signal is a digital signal processor 4
If the control signal is output so as to lower the calculation level inside the control unit, control is performed to lower the sound level by the preceding level control device (S13), and control to increase the sound level is performed by the subsequent level control device (S13). S14). For example, by performing control of lowering the sound level by 2 dB by the level control device at the preceding stage and increasing control by 2 dB by the level control device of the subsequent stage, the saturation of the sound level due to the lowering of the sound level of the internal arithmetic processing is prevented, and The level is kept constant.

Further, the digital signal processing device 4 obtains a level control signal from the control section 9 and outputs a control signal so that the level control signal raises the operation level inside the digital signal processing device 4. In this case, control for raising the audio level is performed by the level control device at the preceding stage (S1).
5) Further, control of lowering the audio level is performed by the subsequent level control device (S16). For example, by performing control to increase by 2 dB by the level control device at the preceding stage and by performing control to decrease by 2 dB by the level control device at the subsequent stage, it is possible to improve the calculation accuracy by increasing the sound level of the internal calculation process, and to improve the input accuracy. The output level is kept constant.

[0024]

As is apparent from the above description, according to the present invention, the deterioration of the calculation accuracy in the digital signal processing such as the DSP and the internal processing of the digital signal processing apparatus is minimized by the control unit such as the microcomputer. In this case, high sound quality can be achieved by preventing saturation when a large volume is input.

[Brief description of the drawings]

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

FIG. 2 is a functional block diagram of a device for generating audio signal level data in the digital signal processing device.

FIG. 3 is a functional block diagram of a device for performing audio level control and glyco control in the digital signal processing device.

FIG. 4 is a flowchart showing processing in a control unit.

FIG. 5 is a flowchart showing processing in the digital signal processing device.

[Explanation of symbols]

 Reference Signs List 1 music source reproducing device 2, 6 low pass filter (LPF) 3 A / D converter 4 digital signal processing device 5 D / A converter 7 power amplifier 8 speaker 9 control unit (microcomputer) 10 operation unit 11 display unit

Claims (3)

[Claims] An A / D converter for converting an analog audio signal from a music source into a digital signal; and generating level data from the digital audio signal from the A / D converter and outputting the data to a control unit. A digital signal processing device for performing a volume level control based on the level control signal in an internal process of the digital signal processing device in accordance with a volume level control signal from the control unit and a level control amount of the glyco, a level from the digital signal processing device; Generate a volume level control signal from the data, and output the volume level control signal to the digital signal processing device again,
An audio apparatus comprising: a control unit that outputs a level control signal of a glyco in response to a user operation; and a D / A converter that converts an audio signal from the digital signal processing device into an analog signal. 2. The control unit according to claim 1, wherein, when data having a volume level higher than a reference value is input from the digital signal processing device and when a volume amplification level controlled by a glyco is high, a volume level calculated inside the signal processing is calculated. 2. The sound apparatus according to claim 1, wherein the sound level control signal is generated so as to lower the sound level. 3. The control unit according to claim 2, wherein, when data having a volume level lower than the reference value is input from the digital signal processing device and the volume attenuation level controlled by the glyco is large, the control unit calculates the volume level calculated inside the signal processing. 2. The sound apparatus according to claim 1, wherein the sound level control signal is generated so as to raise the sound level.