JPH06311587A - Automatic network gain setting method for audio device - Google Patents

Abstract

PURPOSE:To easily adjust level difference by finding a mean level at every band, and letting a differential value between the mean level of a target curve in each band and that of a measured curve be the network gain value of the respective bands. CONSTITUTION:The whole bands of measured frequency characteristic are divided into 31 bands, and are displayed by bar graphs S. The mean value of a target curve in each divided band is calculated, and the mean value of the measured frequency characteristic of each band is calculated, and the mean value Ia of the target curve I and the mean value Sa of the measured frequency characteristics are obtained. Thence, relative movement is performed so as to eliminate the difference between the mean value of the target curve at an arbitrary band, i.e., an arbitrary network and that of the frequency characteristic. The differential value between the mean value of the target curve in remaining respective bands and that of the frequency characteristic is defined as the network gain value to be set in respective area. The data of the network gain value are sent out from an audio analyzer to a DSP part and the setting of a network gain is performed.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network gain setting method in an audio device for acoustically correcting a voice signal carrying music information obtained from a predetermined sound source.

[0003]

[0002]

[0004]

2. Description of the Related Art Parametric equalizers (hereinafter referred to as "P-EQ") are applied to recording media such as tapes and compact discs (hereinafter referred to as "CD") on which music information is recorded, and audio signals obtained from other sound sources. Is used to emphasize a specific frequency band, and a digital sound processor (hereinafter referred to as “DSP”) is used to correct a sound field. The technology regarding is widely known. In particular, in recent years, vehicle-mounted audio devices equipped with such a sound correction function have become widespread.

[0005]

In such a vehicle-mounted audio device, the size and shape of the passenger compartment, the material of the seat, the accessories in the vehicle, and the like vary from vehicle to vehicle, so the acoustic environment is not the same. That is, even if acoustic correction such as network gain setting is performed, the same acoustic effect is not always obtained.

[0006]

Therefore, when such an audio device is installed in a car, an expert such as a dealer sets the network gain while listening to the sound actually emitted from the speaker after installation and adjusts it to a desired frequency characteristic. By doing so, the optimum setting was made for the acoustic environment of the car.

[0007]

[0005]

[0008]

However, in the above-mentioned conventional technique, since the network gain is adjusted while actually listening to the sound emitted from the speaker, not only a great amount of time is required for the adjustment, but also the type of music piece to be played or There is a problem that the adjustment result differs depending on the skill of the adjusting expert and the mood at that time, and universal adjustment cannot be performed. Furthermore, adjusting the level difference between the front side and the rear side of the car was a difficult task for professionals.

[0009]

Further, the user cannot know the objective data of the network gain setting, and if the data stored in the memory in the apparatus is lost for some reason, the same network gain is set. There was also a problem that it was very difficult to do.

[0010]

The present invention solves the problems of the prior art as described above. The universal adjustment of the network gain can be performed in a short time, and the level difference between the front side and the rear side of the vehicle can be easily adjusted. It is an object of the present invention to provide an excellent method for automatically setting a network gain of an audio device, which can be adjusted to the same value and can set the same network gain even when the data stored in the memory is lost.

[0011]

[0008]

[0012]

In order to achieve the above-mentioned conventional object, the present invention divides a frequency band of an audio signal to be handled into a plurality of bands, and replaces the audio signal with a reference audio signal from a speaker. For the measurement curve obtained by measuring the obtained voice, obtain the average level for each band, of the average level of each band of the target curve and the average level of each band of the measurement curve of the average level of any one band The difference is shifted so that the difference disappears, and the difference value between the average level of the target curve and the average level of the measurement curve in each of the remaining bands is set as the network gain value of each band.

[0013]

[0009]

[0014]

Therefore, according to the present invention, the universal adjustment of the network gain can be performed in a short time, and the level difference between the front side and the rear side of the vehicle can be easily adjusted and stored in the memory. The same network gain can be set even if the stored data is lost.

[0015]

[0010]

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[0017]

FIG. 1 is a block diagram showing the configuration of a system to which the network gain automatic setting method for an audio apparatus of the present invention is applied. In FIG. 1, among the connection lines that connect the blocks, the solid line indicates a signal line for transmitting an audio signal, and the dotted line indicates a control line for transmitting a control signal. Reference numeral 1 denotes a center unit as a main body device, which receives a command from an operation unit, and by a master microcomputer installed therein, a source unit such as a tuner unit, a tape deck, a CD deck, and a CD autochanger as a sound source. The slave microcomputer is intensively controlled via a computer line to select and output the audio signal of the source according to the operation.

[0018]

Reference numeral 2 denotes a DSP section as an acoustic correction means, which performs acoustic correction on the audio signal output from the center unit 1 to create an audio signal having a desired frequency characteristic. A main amplifier 3 amplifies and outputs an analog audio signal output from the DSP unit 2. Reference numeral 4 denotes a speaker, which receives a voice signal from the main amplifier 3 and generates a sound.

[0019]

An audio analyzer 5 comprises an analyzer 6 and a personal computer 7. PC 7
The control line between the DSP unit 2 and the DSP unit 2 is composed of RS232C, and the signal line from the analyzer 6 to the DSP unit 2 is composed of an optical cable. Further, 8 is a microphone, which inputs an audio signal obtained by collecting the sound generated from the speaker 4 to the analyzer 6. 1a is the center unit 1
Is a remote control for remote control.

[0020]

FIG. 2 is a block diagram showing the internal structure of the DSP section 2 in FIG. In FIG. 2, reference numeral 20 denotes an audio input unit, which selectively selects either the audio signal output from the center unit 1 or the reference audio signal output from the analyzer 6 according to a selection signal supplied. Input to the next stage. Reference numeral 21 denotes a parametric equalizer (hereinafter referred to as "P-EQ adjustment unit"), which emphasizes a specific frequency band by given parameter data and corrects the frequency characteristic of the input audio signal.

[0021]

Reference numeral 22 denotes a network adjusting unit, which is PE
The audio signal sent from Q21 is divided into a plurality of frequency bands, gain-controlled and output, and so-called time alignment correction for adjusting the transmission time to reach each speaker is also performed. A communication unit 23 processes a control signal transmitted to and from the personal computer 7. In the case of this embodiment, it is composed of an RS232C interface. 24 is a microcomputer,
It controls the operation of the DSP unit 2. Reference numeral 25 is a backup memory, which is a storage means for storing parameter data for the P-EQ 21 to perform acoustic correction, and is composed of an E ² PROM or the like.

[0022]

Reference numerals 26 to 29 denote D / A converters, which convert the digital audio signals for each band sent from the network adjusting unit 22 into analog audio signals. The D / A converter 26 is for a subwoofer, and converts and outputs L-channel and R-channel very low frequency audio signals. The D / A converter 27 is for a woofer, and converts and outputs audio signals of a total of four channels of low frequencies of the L channel and the R channel for the front and the rear, respectively. Similarly, the D / A converters 28 and 29 also convert the middle and high range audio signals of the L channel and the R channel for the front and rear channels, respectively, and output them. Therefore, the D / A converters 26 to 29 convert digital audio signals of a total of 14 channels into analog audio signals and send them out.

[0023]

FIG. 3 is a block diagram showing the internal structure of the audio analyzer 5 in FIG. In the analyzer unit 6 of FIG. 3, reference numeral 60 denotes a microphone sound analysis unit, which converts an analog voice signal input from the microphone 8 into a digital signal, analyzes the voice signal with a built-in microcomputer, and sends analysis data. At the same time, the control signal is transmitted to and from the personal computer 7. Reference numeral 61 is a measurement noise generating unit, which sends a reference voice signal as pink noise to the DSP unit 2 and causes the personal computer 7 to use a built-in microcomputer.
Control signals are transmitted to and from.

[0024]

In the personal computer section of FIG. 3, reference numeral 70 denotes a control section composed of a microcomputer or the like. As described above, a control signal is sent between the microphone sound analysis section 60 and the measurement noise generation section 61 of the analyzer section 6. To transmit. Reference numeral 71 denotes a communication unit, which sets the parameters of the P-EQ adjustment unit 21 of the DSP unit 2, the time alignment and the network gain of the network adjustment unit 22 based on the communication procedure of RS232C with the communication unit 23 of the DSP unit 2. The control signal and data for determination are transmitted.

[0025]

Reference numeral 72 denotes a key input unit, which can set the frequency characteristic of the audio signal to a desired characteristic curve (hereinafter referred to as "target curve") by key operation. A display unit 73 displays a main menu, a tuning menu, confirmation of speaker connection, etc. when performing automatic adjustment, and various data during adjustment. A printing unit (printer) 74 can print not only the result data after completion of the adjustment but also any data during the adjustment.

[0026]

Reference numeral 75 denotes a data storage unit, which is provided on a recording medium such as a floppy disk or a hard disk and has a P-EQ 21.
Parameter data, time alignment and network gain data, and target curve data can be stored and saved. Therefore, after saving the current setting data in the data storage unit 75 when performing automatic adjustment,
Even when the result of the automatic adjustment does not provide the desired characteristics, it is possible to restore the original setting data.

[0027]

The network automatic setting method in the present embodiment compares the measurement curve of the speaker audio signal obtained from the speaker via the microphone 8 according to pink noise, that is, the measured frequency characteristic with the set target curve. It is realized by the method of adjusting the network gain.

[0028]

In the present embodiment, the speakers on the front side are High, Mid, Low and Sub-woo.
4 WAY configuration of fer, High, Mi on the rear side
It is a 3-way configuration of d and Low. Therefore, the front side is divided into four bands, and the rear side is divided into three bands. Each divided band is set by inputting a cutoff frequency. Further, in dividing each band, a slope is provided at the boundary to prevent the output of the speaker from frequently changing with respect to the sound near the boundary. The slope is determined by the slope of the gain increase / decrease level at the frequency next to the cutoff frequency.

[0029]

FIG. 4 is a diagram showing a target curve on the front side and measured frequency characteristics, that is, a measurement curve in the audio frequency band from 20 Hz to 20 kHz. 5 to 8 are diagrams showing a process of automatically setting the network gain. Further, FIG. 9 is a flow chart showing an automatic network gain setting method in the present embodiment. The network gain automatic setting method of the present invention will be described with reference to FIGS.

[0030]

In FIG. 9, first, when the set target curve can be corrected, its frequency characteristic is measured (step S1). This measured frequency characteristic is
As shown in FIG. 4, the entire band is set to 31 bands and is displayed as a bar graph S. Then, the average value of the target curve of each divided band is calculated (step S2), and the average value of the measured frequency characteristics of each band is calculated (step S3). FIG. 5 shows the average value Ia of each band of the target curve I and the average value Sa of each band of the measured frequency characteristic S.

[0031]

Next, relative movement is performed so that there is no difference between the average value of the target curve and the average value of the frequency characteristics in any band, that is, in any network (step S4). That is, as shown in FIG. 6, it is moved (shifted) so that there is no difference between the average value Ia2 of the target curve in the Low band and the average value Sa2 of the frequency characteristics.

[0032]

FIG. 7 is a diagram showing a state in which the average value of the target curve and the average value of the frequency characteristic are moved so that there is no difference (superimposed on the graph). In FIG. 7, the difference value between the average value of the target curve and the average value of the frequency characteristics in each of the remaining bands is set as the network gain value to be set in each band (step S5).

[0033]

Then, the network gain value data is sent from the audio analyzer 5 to the DSP section 2 to set the network gain. The same process is performed on the rear side to set the network gain.

[0034]

Further, the difference between the target curves on the front and rear sides is obtained (step S6). In this case, if the average level of the entire target curve is taken, it is affected by the low and high frequencies above and below the audible range. The average level may drop. In reality, it is more realistic to compare average levels in the midrange that is often heard by the human ear. Therefore, in the present embodiment, the average level value when obtaining the front / rear level difference is obtained from several points in the middle range, and the difference is used as the front / rear level difference of the network gain. That is, as shown in FIG. 8, 320 Hz, 400 H
Using the average level values of the four points of z, 500 Hz, and 630 Hz, the target curve difference = front average level value−rear average level value is obtained.

[0035]

Similarly, the frequency characteristics on the front side and the rear side are measured (step S7), and from the front / rear frequency characteristics at the four frequency points shown in FIG.
The frequency characteristic difference, that is, the measurement curve difference is obtained (step S8).

[0036]

Frequency characteristic difference = front average level value−
Rear average level value The difference between the two is substituted into the following equation to obtain a level difference value from each curve difference (step S9).

[0037]

Level difference value = frequency characteristic difference-target curve difference Next, it is judged whether or not the obtained level difference value is positive (step S10). When this value is positive, this difference is calculated from the front network gain value. Subtract the value (step S
11) If this value is negative, the difference value is subtracted from the rear network gain value (step S12).

[0038]

The front / rear network gain values thus obtained are used as the final attenuated data of the audio output in the network adjusting section 22 of the DSP section 2 shown in FIG. Although this attenuator data is registered in the backup memory 25 of the DSP unit 2, it is also stored in the data storage unit 75 of the audio analyzer 5 at the same time.
Even if the data of 5 is lost, the same network gain setting can be reproduced.

[0039]

[0033]

[0040]

As is apparent from the above embodiments, according to the network gain automatic setting method for an audio device of the present invention, universal adjustment of the network gain can be performed in a short time, and the front side of the vehicle can be adjusted. The level difference between the rear side and the rear side can be easily adjusted, and the same network gain can be set even if the data stored in the memory is lost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system to which an automatic network gain setting method for an audio device of the present invention is applied.

FIG. 2 is a block diagram showing an internal configuration of a DSP unit 2 in FIG.

3 is a block diagram showing an internal configuration of an audio analyzer 5 in FIG.

FIG. 4 is a diagram showing a target curve on the front side and measured frequency characteristics in an audio frequency band.

FIG. 5 is a diagram showing an average value of each band of a target curve and an average value of measured frequency characteristics of each band.

FIG. 6 is a diagram showing an average value of a target curve for each band and an average value of frequency characteristics for each band.

FIG. 7 is a diagram showing a state where movement is performed so as to eliminate a difference between an average value of a target curve and an average value of frequency characteristics.

FIG. 8 is a diagram showing that a target curve difference is obtained using an average level value of four points.

FIG. 9 is a flowchart showing a method for automatically setting a network gain in this embodiment.

[Explanation of symbols]

 1 Center unit (main unit) 2 DSP section 4 Speaker 8 Microphone 5 Audio analyzer 22 Network adjustment section 25 Backup memory

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location H04R 5/02 F 8421-5H H04S 7/00 Z 8421-5H (72) Inventor Issei Kikuchi Tokyo 5-35-2 Hakusan, Bunkyo-ku Clarion Co., Ltd.

Claims (2)

[Claims] 1. A network gain setting method for dividing a frequency band of a voice signal to be handled into a plurality of bands to configure a network, and setting a network gain value for each band, which comprises designating a frequency characteristic of the voice signal. For the obtained target curve, obtain the average level for each band, for the measurement curve obtained by measuring the voice obtained from the speaker according to the reference voice signal instead of the voice signal, obtain the average level for each band, Shift to eliminate the difference between the average level of each band of the target curve and the average level of any one band of the measurement curve, and measure the average level of the target curve in each remaining band. Audio characterized by using the difference value from the average level of the curve as the network gain value of each band Network gain automatic setting method of the location. 2. The audio device is a device mounted on a vehicle, after setting the network gain value for each of a speaker installed on a front side of the vehicle and a speaker installed on a rear side of the vehicle. 2. The automatic network gain setting method for an audio device according to claim 1, wherein the shifting is performed so that the level difference between the predetermined frequencies on the front side and the rear side is eliminated.