JPH0632541B2 - Equalizer device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equalizer device, for example, an equalizer device that automatically controls a sound field in an automobile.

Conventional Configuration and Problems There have been conventionally proposed equalizer devices having an equalizer device for automatically controlling a sound field in an automobile and a display device for displaying equalizer characteristics. That is, an equalizer device has been proposed which detects a sound field measurement signal emitted from a speaker with a microphone, analyzes the frequency of the detected signal, and automatically corrects the equalizer circuit according to the analysis result.

However, in the above-mentioned conventional example, since the function of notifying whether the correction of the equalizer circuit can be corrected is not provided, the usability is poor.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to provide an equalizer device which displays whether or not the correction by the equalizer circuit is possible and how it cannot be corrected.

In order to achieve the above object, the present invention determines whether or not the correction by the equalizer circuit is possible, and when the correction is impossible, the display device for displaying the equalizer characteristic is used. The frequency band that cannot be corrected and the side of the frequency band that cannot be corrected are displayed.

Description of Embodiments FIGS. 1A and 1B show a reproducing system using an 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. In FIG. 2, 5 is an equalizer main body, and 6 is a display section for performing equalizer characteristic display or spectrum analyzer display. This display section 6 has 13 × 7 display elements 7 arranged vertically and horizontally. Each row is 65Hz, 250Hz, 5 from the left
It constitutes a display unit for each frequency band of 00 Hz, 1 KHz, 1.8 KHz, 4 KHz, and 10 KHz. Reference numeral 8 is a display element provided corresponding to each frequency band, and the display element 8 is sequentially turned on in response to the operation of the frequency band selection button 9 to display the frequency band to be adjusted. That is, every time the left end of the frequency band selection button 9 is operated,
The lighting of the display element 8 is sequentially switched to the left side, and every time the right end of the frequency band button 9 is operated,
The lighting of the display element 8 is sequentially switched to the right side.

10 and 11 are sound quality adjustment buttons, and sound quality adjustment button 1
When 0 is operated, the level of the frequency band selected by the frequency band selection button 9 is gradually increased and the display element 7
The lighting of is sequentially switched to the upper side. Further, when the sound quality adjustment button 11 is operated, the level of the frequency band selected by the frequency band selection button 9 is sequentially lowered, and the lighting of the display element 7 is sequentially switched downward. Reference numeral 12 denotes a display switching button. When the display switching button 12 is operated, the display section 6 is switched between the equalizer characteristic display and the spectrum analyzer display. Reference numeral 13 denotes an auto equalize button. When the auto equalize button 13 is operated, the sound field in the room is automatically corrected. Reference numeral 14 is a defeet button. When the defeet button 14 is operated, the equalizer circuit and the display circuit are turned off. 1
Reference numeral 5 denotes an automatic volume correction button. When the automatic volume correction button 15 is operated, the volume is automatically corrected according to the noise level. Reference numeral 16 denotes an internal microphone. The internal microphone 16 detects the level of a frequency modulation sound (wobble tone) radiated from the speaker 4 in the auto equalization mode, or detects the noise level in the automatic volume correction mode. 17 is an external microphone 18
Is the jack to which is connected. When the external microphone 18 is inserted into the jack 17, the internal microphone 1
Instead of 6, the level of the frequency modulated sound at the position of the external microphone 18 or the noise level is detected. 19
a, 19b and 19c are memory buttons for storing the frequency characteristic in the memory and reading the frequency characteristic stored in the memory, and 20 is for adjusting the volume of the speaker arranged in the front and the speaker arranged in the rear. It is a fader control knob for doing.

FIG. 3 shows the configuration of the equalizer device 2. In FIG. 3, 21 is an input terminal to which an acoustic signal output from the audio device 1 is applied, and 22 is an analog switch for selecting an acoustic signal applied to the input terminal 21 or a wobble tone output from the wobble tone generator 23. Yes,
This analog switch is controlled by the control unit described later. The wobble tone generator 23 is a sound field measurement signal that is frequency-modulated (modulation frequency 8 Hz).
5Hz, 250Hz, 500Hz, 1KHz, 1.8KHz, 4KH
Generates wobble tones of z and 10 KHz in sequence. 24, 2
5 is an analog switch, and this analog switch 2
4, 25 are controlled by the control unit. Reference numeral 26 denotes an equalizer circuit, and the equalizer circuit 26 has a plurality of band pass filters BPF1 to BPF7 having different frequency bands.
And a plurality of electronic volumes V1 to V7 for adjusting the output levels of the bandpass filters BPF1 to BPF7. The electronic volumes V1 to V7 are controlled by control signals from the control unit 27. That is, the control signal controls the selection of the electronic volumes V1 to V7 and the attenuation degree of the selected electronic volume. The control unit 2
Reference numeral 7 is composed of an input / output device (I / O), a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM) and the like. Reference numeral 28 is an operation unit including the various buttons, 3 is the main amplifier, 4 is the speaker, and 16 and 18 are the microphones. 29 is an amplifier for amplifying the output of the microphone 16 or 18, 3
Reference numeral 0 is a filter circuit, and this filter circuit 30 is composed of a plurality of band pass filters BPF1 to BPF1 having different frequency bands.
It is composed of PF8. The bandpass filters BPF1 to BPF7 of the filter circuit 30, like the bandpass filters BPF1 to BPF7 in the equalizer circuit 26, are 65 Hz, 250 Hz, 500 Hz, 1 KHz, and 1.8 KH, respectively.
The bandpass filter BPF8 of the filter circuit 30 has a center frequency of z, 4 KHz, and 10 KHz, and the bandpass filter BPF8 of the filter circuit 30 has a center frequency of 20 Hz.
The PF 8 is used to detect the ambient noise level in the automatic volume control mode. Reference numeral 31 is a switching circuit that selects the outputs of the bandpass filters BPF1 to BPF8 of the filter circuit 30, reference numeral 32 is an analog output of the bandpass filters BPF1 to BPF8 selected by the switching circuit 31,
A / D converter for digital conversion, 33 is a bandpass filter BPF1 converted into a digital value by the A / D converter 32.
Is a comparison circuit that compares the output of the BPF 8 with a predetermined value and outputs a value corresponding to the difference. The output of the comparison circuit 33 is input to the control unit 27. The display unit 6 is controlled by a control signal from the control unit 27.

In FIG. 3, when adjusting the sound quality, first, the frequency band selection button 9 of the operation unit 28 is operated, and then the sound quality adjustment buttons 10 and 11 are operated. A control signal is generated from the control unit 27 in response to this button operation, and the control signal selects the electronic volumes V1 to V7 in the equalizer circuit 26, changes the attenuation of the selected electronic volume, and displays the display unit 6. The lighting of the display element 7 is switched.

In FIG. 3, when the auto equalize button 13 in the operation unit 28 is operated, an automatic sound field correction operation is performed.
That is, when the auto equalize button 13 is operated,
The wobble tone generated by the wobble tone generator 23 is the analog switches 22, 24, 25 and the main amplifier 3.
Is applied to the speaker 4 via. The sound radiated from the speaker 4 is detected by the microphone 16 or 18,
Via the amplifier 29, the filter circuit 30, and the switching circuit 31
It is applied to the A / D converter 32 and converted into a digital value. The value output from the A / D name converter 32 (the value corresponding to the output level of each bandpass filter BPF1 to BPF7) is sequentially compared with a predetermined value by the comparison circuit 33, and the value corresponding to the difference is sequentially output. . That is, the microphone 16
Alternatively, the level of each frequency band of the sound detected in 18 is sequentially compared with a predetermined value, and a value corresponding to each difference is input to the control unit 27. The control unit 27 obtains a value for making the difference value for each frequency band zero, controls the attenuation degree of each of the electronic volumes V1 to V7 of the equalizer circuit 26, and displays the corrected equalizer characteristic on the display unit 6.

FIG. 4 shows an error display function block in the automatic equalizer mode, which is a feature of this embodiment. In FIG. 4, reference numeral 33 denotes the comparison circuit, and the comparison circuit 33
Then, the level of each frequency band of the sound field measurement signal detected by the microphone 16 or 18 is compared with a predetermined value, and a difference signal corresponding to the difference is output. Reference numeral 34H is a comparison means for comparing whether or not the difference signal in the high frequency band 10 KHz output from the comparison circuit 33 is larger than a first predetermined value, 3
4L is a comparison means for comparing whether or not the difference signal in the high frequency band (10 KHz) is smaller than the second predetermined value, and 35H is the difference signal in the low frequency band (65 Hz) output from the comparison circuit 33. A comparison means for comparing whether or not the difference signal is larger than a predetermined value, 35L is a comparison means for comparing whether or not the difference signal in the low frequency band (65 Hz) is smaller than a second predetermined value, and 36 is a comparison means 34H, 34L, 35H. , 35L are input to generate a control signal, and a control signal from the control signal generating means 36 is applied to the display unit 6 and the sounding device 37. The correctable range of the equalizer circuit 26 in the present embodiment is ± 12 dB, and if the output of the comparison circuit 33 is out of this correctable range, the equalizer characteristics cannot be corrected. Therefore, in this embodiment, the comparison means 34H, 34L, 35H, 3
Whether or not correction is possible is determined by 5L. If the correction is not possible, a control signal is output, which of the high and low frequency bands cannot be completely corrected is displayed on the display unit 6, and an alarm is issued by the sounding device 37. It is given for a predetermined time. 5A and 5B show display examples on the display unit 6, and FIG. 5A shows a low frequency band (65 Hz) and a high frequency band (10 KH).
z) is insufficient, and in this case, “HH” is displayed on the display unit 6 and 65 Hz and 10 KH
The display elements (a) and (b) corresponding to +12 dB in the display element group for the z band are blinked. FIG. 5B shows the low frequency band (65
Hz) is too high and the high frequency range (10 KHz) is insufficient. In this case, "LH" is displayed and it corresponds to -12 dB in the display element group for the 65 Hz band. The display element (c) and the display element (b) corresponding to +12 dB in the display element group for the 10 KHz band are made to blink. In FIG. 4, reference numeral 38 is a control signal generating means for generating a control signal for equalizer correction based on the output of the comparison circuit 33.

EFFECTS OF THE INVENTION According to the present invention, it is possible to display which of the high and low frequency bands is disturbed and how it is disturbed when the disturbance of the characteristics is too large to be corrected.

Further, according to the present invention, since the frequency band in which the characteristic is disturbed is displayed by characters by using the display device that originally displays the equalizer characteristic, the frequency characteristic is disturbed by a simple configuration without adding a separate display device. This has the advantage that the existing frequency band can be easily recognized at a glance.

[Brief description of drawings]

1A and 1B are block diagrams of a reproducing system using the equalizer device of the present invention, FIG. 2 is a front view of the equalizer device in one embodiment of the present invention, FIG. 3 is the same block diagram, and FIG. 5 is a functional block diagram of a part of the device, and FIGS. 5A and 5B are diagrams showing display examples on the display device of the device. 1 ... Audio equipment, 2 ... Equalizer device, 3 ... Main amplifier, 4 ... Speaker, 5 ... Equalizer body, 6 ...
... Display unit, 7, 8 ... Display element, 9 ... Frequency band selection button, 10, 11 ... Sound quality adjustment button, 12 ... Display switching button, 13 ... Auto equalize button, 14 ...
… Defeet button, 15… Automatic volume control button,
16 ... Microphone, 17 ... Jack, 18 ... Microphone, 19a, 19b, 19c ... Memory button, 20 ... Fader control knob, 21 ...
Input terminal, 22 ... Analog switch, 23 ... Wobble tone generator, 24,25 ... Analog switch, 2
6 ... Equalizer circuit, BPF1 to BPF8 ... Band pass filter, V1 to V7 ... Electronic volume, 27 ...
... Control unit, 28 ... Operation unit, 29 ... Amplifier, 30 ...
Filter circuit, 31 ... Switching circuit, 32 ... A / D converter, 33 ... Comparison circuit, 34H, 34L, 35H, 35
L ... Comparison means, 36 ... Control signal generation means, 37 ...
Sound generator, 38 ... Control signal generator.

Claims (3)

[Claims] 1. A comparison circuit which detects a sound field measuring signal radiated from a speaker and outputs a difference signal between a high frequency band level and a low frequency band level of the detection signal and a predetermined value, and a comparison circuit. Comparing means for comparing whether or not the difference signal output from the circuit exceeds the upper limit value and the lower limit value of a predetermined range, and display control signal generating means for outputting a display control signal in accordance with the comparison result by the comparing means. An equalizer device comprising: a display device in which a plurality of display elements are arranged vertically and horizontally, the display control signal is applied to the display device, and the comparison result is displayed in characters on the display device. 2. The equalizer device according to claim 1, wherein the display device group on the low frequency side or the display device group on the high frequency side of the display device displays characters meaning high or low. 3. The equalizer device according to claim 1, wherein the upper or lower display element of the low frequency band display element group or the high frequency band display element group of the display device is turned on or blinked.