JPS60245400A - Equalizer - Google Patents

Abstract

PURPOSE:To execute securely a sufficient sound field correction even if right and left speakers and a sound receiving point are asymmetric by correcting a characteristic of an equalizer circuit for a right or left based on a frequency analyzed result of the right or left channel. CONSTITUTION:When an autoequalizer button of an operating part 28 is operated, a storage means 34 is controlled by a storage control means 35, and an initial value of an equalizer circuit, which is stored on the stroage means 34, is read out, which causes equalizer circuits 26R and 26L to set to initial values. Measuring signals radiated from a right speaker are sound-collected by a microphone, and the collected sound is added as level data to an arithmetic means 33 through an A/D converter circuit 32. The arithmetic means 33 obtains an average, and a difference between said average and the level data of each frequency band is obtained. This difference data is added to an equalizer circuit 27R through a switching means 37, and the attenuation degree of each electronic volume is modified. The correction of the left channel can be made in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an equalizer device, and particularly to an equalizer device that automatically controls a sound field in a listening room where left and right speakers and listening points are asymmetrical.

Conventional Structure and Problems There has been proposed an equalizer device that includes a right channel equalizer circuit and a left channel equalizer circuit and automatically corrects equalizer characteristics. However, this type of conventional equalizer device simultaneously applies measurement signals such as pink noise to the left channel and right channel equalizer circuits, and collects the sound emitted from the right channel and left channel speakers with a microphone. The system would generate sound, perform frequency division analysis, and based on the results of this analysis, correct the equalizer circuits for the left channel and right channel so that they had the same characteristics.

However, since the left speaker, right speaker, and listening point in the interior of a car are generally not symmetrical but asymmetrical, when correcting the left and right equalizer circuits to have the same characteristics as in the conventional example above, a sufficient sound field cannot be achieved. There was a drawback that it could not be corrected.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks and provides an equalizer device that can reliably perform sufficient sound field correction even if the left and right speakers and the listening point are asymmetrical.

Structure of the Invention In order to achieve the above object, the present invention performs frequency analysis of the left and right channels separately, corrects the characteristics of the left channel equalizer circuit based on the frequency analysis results of the left channel, and adjusts the frequency of the right channel. The characteristics of the right channel equalizer circuit are corrected based on the analysis results.

DESCRIPTION OF THE EMBODIMENTS FIGS. 1A and 1B show a reproduction system using the equalizer device of the present invention. In FIG. 1, 1 is an audio device such as a deck, 2 is an equalizer device of the present invention, 3 is a main amplifier, and 4 is a speaker.

FIG. 2 shows the front of the equalizer device 2. As shown in FIG. In FIG. 2, 5 is the equalizer main body, and 6 is a display section for displaying equalizer characteristics or spectrum analyzer display.This display section 6 has 13.times.7 display elements 7 arranged vertically and horizontally. Each column is 65Hz from the left, 25 Q
lz, 500Hz, iKHz.

1, 8 IIGJz, 4 KHz, 10 K11z
This constitutes a display section for each frequency band. Reference numeral 8 denotes a display element provided corresponding to each frequency band, and the display element 8 is sequentially turned on or off in accordance with the operation of the frequency band selection button 9 to display the frequency band to be adjusted.

10.1.1 is a sound quality adjustment button, and when this sound quality adjustment button 10 or ]1 is operated, the level of the frequency band selected with the frequency band selection button 9 is sequentially changed, and the display element 7 is turned on in sequence. Can be switched. 1
2 is a display switching button, and when this display switching button 12 is operated, the display section 6 is switched between an equalizer characteristic display and a spectrum analyzer display. 13 is an auto equalize button, and this auto equalize button 13
When you operate , the indoor sound field is automatically corrected. 14
is a defeat button, and when this defeat button 14 is operated, the equalizer circuit and display circuit are turned off. 15 is an automatic volume correction button, and when this automatic volume correction button 15 is operated, the volume is automatically corrected according to the noise level. 16 is an internal microphone, and this internal microphone 16 detects the level of frequency modulated sound (warble tone) emitted from the speaker 4 in the automatic equalization mode, and detects the noise level in the automatic volume correction mode.

17 is a jack to which an external microphone 18 is connected. When the external microphone 18 is inserted into the jack 17, the level of frequency modulated sound or the noise level at the position of the external microphone 18 is detected instead of the internal microphone 16.

19a, 19b, and 19c are memory buttons for storing frequency characteristics in memory and reading out frequency characteristics stored in memory, respectively; 20 is for adjusting the volume of the speakers placed in the front and the speakers placed in the rear. This is the ultimate fader control knob.

FIG. 3 shows the configuration of the equalizer device 2. As shown in FIG.

In FIG. 3, 21R, 2]L are the right channel and left channel audio signals JL6" output from the audio equipment 1.
The input terminals 22 & 22L to which the voltage is applied are the input terminals 21.
The acoustic signals applied to [R, 2] and L are analog switches that select the wobble tone output from the wobble tone generator 23, and this analog switch is controlled by a control section that will be described later. The warble tone generator 23 is a signal generator that generates a frequency modulated sound field measurement signal (modulation frequency: 13 Hz), and is, for example, a 55
Hz.

250flz, 500Hz, IKI]z, ],,
8KIIz, 4KITz, 10I (Hz measurement signals are generated sequentially. 24R, 24L.

2511,. 25T is an analog switch, and the analog switches 24R, 24L, 25R, and 25'L are controlled by a control section. 2f3FL, 26L are equalizer circuits, and these equalizer circuits 26R, 26
L is a plurality of bandpass filters F1 with different frequency bands
~F7, and a plurality of electronic voices IJ and -V1~V7 that adjust the output levels of the respective bandpass filters F1~F7. Each electronic volume V1 to V7 is controlled by a control signal from a control section 27. That is, the selection of the electronic volumes 1 to V7 and the degree of attenuation of the selected electronic volume are controlled by the control signal. The control section 2
7 is an input/output device (Ilo) and a central processing unit (CPU).

It consists of read-only memory (R, OM), random access memory (RAM), etc. 28 is the operation unit including the various buttons, 3R and 3L are the main amplifiers,
4R and 4L are the aforementioned speakers.

16.1.8 is the microphone. Reference numeral 29 is an amplifier for amplifying the output of the microphone 16 or 18, and 30 is a filter circuit. This filter circuit 30 is composed of a plurality of filters F1 to F8 having different frequency bands. The bandpass filters F1 to F7 of the filter circuit 30 have a filter width of 651 Tz and 2 Tz, respectively, similar to the pantone filters F1 to F7 in the equalizer circuit 26.
50Hz, 500Hz.

1, KI]z, 1.8KHz, 4KHz, 10K
It has a center frequency of 11z,,'! The bandpass filter F8 of the rr knee filter circuit 30 has a center frequency of 201rz, and this bandpass filter F8 is used to detect the ambient noise level in the automatic volume adjustment mode. 31 is a switching circuit for selecting the outputs of the bandpass filters F1 to F8 of the filter circuit 30;

32 is an A/D converter that converts the outputs of the band filters F1 to F8 selected by the switching circuit 31 from analog to digital; the output of the A/D converter 32 is input to the control unit 27; be done. 6 is the display section, and this display section 6 is controlled by a control signal from the control section 27.

In FIG. 3, when adjusting the sound quality, first operate the frequency band selection button 9 of the operating section 280, then operate the sound quality adjustment buttons 10, 1. ,．． Operate 1. A control signal is generated from the control unit 27 in response to this button operation, and this control signal causes the electronic volume IJ, -V1 to
(2) Selection of 7, change of the attenuation degree of the selected electronic volume IJ, -, and switching of lighting of the display element 7 of the display section 6 are performed.

In FIG. 3, when the auto equalize button 13 in the operation section 28 is operated, automatic sound field correction is performed. That is, when the auto equalize button 13 is operated, the initial values of the equalizer circuits 26R and 26L are set, and the measurement signal generated from the warp tone generator 23 is passed through the equalizer circuit 2f3R or 26L and the main amplifier 3 or 3L. speaker 4R or 4L
is applied to The sound emitted from the speaker 4R or 4L is transmitted through the microphone 16-! or 18, and the amplifier 29. Filter circuit 30. A/
The signal is applied to the D converter 32, converted into a digital value, and input to the control section 27. The control section 27 generates a control signal for each frequency band to control the degree of attenuation of each of the electronic volumes (1) to (7) of the equalizer circuits 26R, 26L, and displays the corrected equalizer characteristics on the display section 6.

FIG. 4 is a diagram showing the control section 27 of the above embodiment in functional blocks. In FIG. 4, 33 is means A, and a predetermined area of this storage means 34 has an equalizer circuit 26R.
, 26L are also stored. 35 is storage means 3
Storage control means 36 controls the writing and reading of data to and from the storage means 34, and 36 is a control signal that controls the electronic volumes ■1 to ■7 of the equalizer circuits 26R and 26L based on the data read out from the storage means 34. The control signal generating means 37 is a switching means, and the switching means 37 is a means for applying the control signal generated by the control signal generating means 36 to the equalizer circuit 26R or 26L. 38
is a timing control signal generating means that generates a timing control signal in response to various signals from the operating section 28, and the output of the timing control signal generating means 38 causes the storage control means 35, the switching means 37. Warble tone control means 3
9. Switching means 40. Controls analog switches 22R922L, etc. 41 is a warp tone generating circuit.

Next, the auto-equalization operation in this embodiment will be explained with reference to FIG. 4.

In FIG. 4, when the auto-equalize button 13 of the operation unit 28 is operated, the storage means 34 is controlled by the storage control means 35, the initial value of the equalizer circuit stored in the storage means 34 is read out, and the equalizer circuit 26
Each electronic volume (1) to (7) in R, 26L is set to an initial value. When the initial value setting of the electronic volumes Vl and -V7 is completed, the time constant circuit in the warp tone generating circuit 41 is sequentially controlled by the warp tone control means 39, and the time constant circuits in the warp tone generating circuit 41 are sequentially set to 65 Hz, 25 f) Hz, 50 QH.
z, I KHz.

Measurement signals of 1.8 KJIz, 4 KHz, and 10 K11z are sequentially output. This measurement signal is supplied to the right channel path via the switching means 40. That is, the measurement signal is sent to the analog switches 22R, 24R,
The signal is applied to the speaker 4R via the equalizer circuit 26R, analog switch 25R, and main amplifier 3R.

Measurement signals of different frequencies sequentially emitted from the speaker 4R are transmitted to the microphone 1 placed at a predetermined location inside the vehicle.
6 or 18, and filter circuit 30. After passing through the switching circuit 31, it is converted into a digital value by the A/D conversion circuit 32. The level data of each frequency band sequentially converted into digital values by the A/D conversion circuit 32 is sent to the calculation means 33.
At the same time, the average value is determined, and the difference between this average value and each frequency band level data is determined, and the average value data and the difference data are stored in the storage means 34. Next, the difference data of each frequency band stored in the storage means 34 is read out, and the control signal generation means 36 generates a control signal. This control signal is applied to the equalizer circuit 26R via the switching means 37, and each electronic volume IJ, -
Change the attenuation degree from 1 to ■7.

Next, 10KHz from the warble tone generation circuit 41.

4KIIZ, 18KH2, 1WhatZ, 500H2,250
z, 65Hz measurement signal is output, similarly supplied to the right channel path, and similarly connected to microphone 16 or 1.
After the sound is collected in step 8, it is converted into A and /D, and the difference between it and the average value found in the previous measurement is determined, and the sound is stored in the storage means 34.
is memorized.

Next, the calculation means 33 determines whether the difference data of each frequency band obtained by the second measurement is within a predetermined range, and if the difference data is outside the predetermined range, the difference data of each frequency band is determined. The difference data is applied to the control signal generating means 36, and the equalizer circuit 26R outputs the electronic signals IJ, - in that frequency band.
Set the attenuation level of the damper again. This completes the correction of the right channel equalizer circuit 26R.

Next, the switching means 37 and 40 are switched to the left channel side, and the same processing as that for the right channel is performed on the left channel, and the attenuation degree of the left channel equalizer circuit is set.

In the above embodiment, after performing frequency analysis of the right channel and correcting the equalizer circuit 26R for the right channel, frequency analysis of the left channel and correction of the equalizer circuit 26L for the left channel are performed. After performing frequency analysis, the equalizer circuits for the right and left channels may be corrected.

Effects of the Invention According to the present invention, it is possible to finely correct the equalizer characteristics of the left and right channels especially in a room where the left and right speakers and the listening point are asymmetrical, such as in a vehicle interior, and has the advantage that sound field correction can be performed reliably. It is something.

[Brief explanation of the drawing]

1A and 1B are block diagrams of a reproduction system using the equalizer device of the present invention, FIG. 2 is a front view of the equalizer device in an embodiment of the present invention, FIG. 3 is the same block diagram, and FIG. It is a functional block diagram of a part of the same device. 1. Audio equipment, 2. Equalizer device, 3. ,3
11. , 3L...main amplifier, 4.4R, 4L...
Speaker, 5. Equalizer body, 6. Display section, 7, 8
- Display element, 9... Frequency band selection button, 10.
11...Sound quality adjustment button, 12...Display switching button,
13...Auto equalize button, 14...Defeat button, 15...Auto volume correction button, 16...
Microphone, 17... Jack, 18 Microphone, 19a. 19b, 19c...Memory button, 2,0-...Fader control knob, 21R, 21L--Input terminal, 22R, 22L-Analog switch, 23 Warble tone generator, 24R, 24L, 25R, 25L...
・Analog switch, 26R, 26L...Equalizer circuit, F1~F8...Band pass filter, Vl~■7
...electronic volume, 27...control unit, 28...operation unit, 29...amplifier, 30...filter circuit, 31...
- Switching circuit, 32- ADD converter, 33... Calculating means, 34... Storage means, 35... Storage control means, 36.
- Control signal generating means, 37... Switching means, 38... Timing control signal generating means, 39... Warble tone control means, 40... Switching means, 41... Warble tone generating circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] a right channel equalizer circuit and a left channel equalizer circuit; a measurement signal generating means for applying a measurement signal to the right channel speaker or the left channel speaker via the right channel or left channel equalizer circuit; Collects the measurement signal emitted from the right channel or left channel speaker,
An equalizer device comprising: a correction means for separately analyzing the frequencies of the right and left channels, and correcting the characteristics of the right channel equalizer circuit and the left channel equalizer circuit separately based on the analysis results of the right and left channels.