JP3374407B2 - System adjustment device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit device for easily and quickly adjusting a reproduction sound pressure level of a speaker in a speaker system in which a plurality of speakers are arranged. 2. Description of the Related Art In a 4ch speaker system for generating left and right stereo output signals, a center output signal and a surround output signal, a power amplifier is used to amplify four output signals and drive corresponding speakers. You. Further, in such a system, a desired surround effect cannot be obtained unless the volume generated from the speakers is balanced. Therefore, in the 4-channel speaker system, a balance adjustment source called a noise sequencer is provided as a system adjustment, and the balance of the power amplifier is adjusted by adjusting the volume of the power amplifier in a state where the output signal of the noise sequencer is applied to the power amplifier. ing. [0003] Such a system is disclosed, for example, in Japanese Utility Model Application Sho 63
-96021. The noise sequencer described in the above publication automatically switches the four output signals at predetermined time intervals (about 1.5 seconds) and applies the output signals to the power amplifier. The balance can be adjusted while checking the volume of the four speakers. [0004] In the above-described conventional system adjustment device, when adjusting the sound pressure level of the sound reproduced from the speakers, a predetermined signal serving as a reference for each speaker, for example, Since the listener had to play the noise and listen to the reproduced sound with his / her own ears and adjust the balance while checking the volume of the four speakers that emitted the sound in sequence, the adjustment accuracy was poor or the adjustment time wasted. There was a problem of consuming. Further, by measuring the reproduced sound with a noise meter or the like, the adjustment accuracy can be improved and the adjustment time can be shortened. However, it is necessary to prepare a noise meter or adjust the volume of the amplifier one by one. was there. The present invention has been made to solve such a problem, and has as its object to easily and quickly adjust the sound pressure level of sound reproduced from a speaker. [0007] In the system adjusting apparatus according to the present invention, a plurality of band noises of different bands are simultaneously reproduced from respective speakers via a plurality of attenuators, and the reproduced reproduction is performed. Sound is picked up by a microphone, a band-pass filter divides the collected signal into a plurality of different bands, a rectifier circuit rectifies the signal divided into each band, and converts the rectified signal into digital data The attenuator for adjusting the level of the band noise is controlled so that the value of the A / D converter is the same as that of the A / D converted digital data. In the system adjustment device configured as described above, the control of the attenuator is performed simultaneously from each speaker.
Plays back and collects the reproduced sound by microphone
Then, the collected signal is extracted by a plurality of band-pass filters that divide the signal into different bands, the signal divided into each band is rectified by a rectifier circuit, and converted into digital data by an A / D converter. since the value is adjusted to be the same, reproduction output sound pressure level of the speakers becomes uniform. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a system adjustment device showing an embodiment of the present invention. In the figure, reference numerals 1a, 1b, 1c, and 1d denote band noises each having a different bandwidth with a bandwidth of 1/3 octave.
a, 17b, 17c and 17d are different source signals, 16 is a switching circuit for switching between the band noise and the source signal, 2a, 2b, 2c and 2d are attenuators, 3
Is an amplifier, 4 is a speaker, 5 is a microphone, 6a, 6b,
6c and 6d are band-pass filters, 7a, 7b, 7c,
7d is a rectifier circuit, 8a, 8b, 8c and 8d are A / D converters, and 9 is a microcomputer, which has a CPU 10, a memory 11, an input circuit 12, and an output circuit 13.
14 is a start switch, and 15 is a display LED. FIG. 2 shows the memory 1 of the microcomputer 9.
2 is a flowchart showing a system adjustment program stored in the first embodiment. First, in the system adjustment, when the start switch 14 is depressed, an ON signal thereof is input to the input circuit 12 of the microcomputer 9 and determined in step 20 to start the adjustment of the system. In step 21, the display LED 15 indicating that the system adjustment is being performed is turned on (lit), and in step 22, the internal flags A, B, C, and D (not shown) are cleared to 0 as an initial set, and band noise and The switching circuit 16 for switching the source signal selects the band noise from the output circuit 13 of the microcomputer 9 and further sets the attenuator to the maximum (-∞). Band noise 1 having different bands
a, 1b, 1c, 1d are attenuators 2a, 2b, 2
c and 2d, and are simultaneously reproduced from the respective speakers 4 via the amplifier 3. Next, the microphone 5 picks up the reproduced noise. The collected noise is transmitted to the band-pass filters 6a and 6a.
In b, 6c, and 6d, it is taken out again as band noise having a different band. The extracted band noises having different bands are rectified by the rectifier circuits 7a, 7b, 7c and 7d, respectively. Then, the A / D converters 8a, 8b, 8c, 8d
Is converted into digital data, and each digital data is input to the input circuit 12 of the microcomputer 9. The microcomputer 9 comprises an A / D converter 8
a, 8b, 8c, and 8d so that the digital data input from the attenuators 2a, 2b, 2c, and 2d are the same.
It works to control d. That is, in step 23, first, the first A /
The data value of the D converter 8a is read, and a reference value, for example, A
Step 2 if not 1/2 of maximum value of / D conversion data
The program proceeds to step 4, where the first attenuator 2a is lowered one step (output increases). If the value is a reference value, the procedure proceeds to step 25 where the internal flag A is set to 1. Next, at step 26, the second A / D converter 8
Read the data value of b, and if it is not the reference value, step 2
7, the second attenuator 2b is lowered by one stage (the output is increased). If the value is the reference value, the process proceeds to step 28, where the internal flag B is set to 1. Next, in step 29, the data value of the third A / D converter 8c is read, and if it is not the reference value, the process proceeds to step 30, where the third attenuator 2c is read.
Is decreased by one stage (the output is increased), and if it is the reference value, the process proceeds to step 31 and the internal flag C is set to 1. Next, at step 32, the data value of the fourth A / D converter 8d is read.
Attenuator 2d down one stage (output up)
If the value is the reference value, the process proceeds to step 34 where the internal flag D
Is set to 1. Next, at step 35, the internal flags A, B,
It is determined whether C and D are all 1, and if not all, the process returns to step 23 and repeats the process.
If so, the first to fourth A / D converters 8a, 8b, 8
The first to fourth attenuators 2a, 2b, 2c,... so that the digital data input from c, 8d are the same.
It is determined that 2d can be controlled, and the process proceeds to step 36, where the display LED 15 is turned off (turned off). And step 3
Switching circuit 1 for switching between band noise and source signal at 7
6, the source signal is selected from the output circuit 13 of the microcomputer 9, and a series of system adjustments is completed. Embodiment 2 FIG. In the above embodiment, the band noise having a plurality of different bands is generated from the band noise generator. However, the band noise having the plurality of different bands is a noise that generates noise as shown in FIG. The signal may be generated by the generator 40 and the band-pass filters 6a, 6b, 6c, 6d having a plurality of different bands. Embodiment 3 FIG. In the above embodiment, the band widths of the band-pass filter and the band noise are set to 1/3 octave. However, in consideration of the reproduction band of a normal speaker, the upper limit of the reproduction band can be reproduced up to about 20 kHz. A relatively wide speaker has a bandwidth of 2/3 octaves, and an upper limit of a reproduction band is about 1 kHz for a speaker having a relatively narrow reproduction band up to about 10 kHz.
A similar effect can be obtained by giving a band width of オ ク タ octave and appropriately setting the band width in a range from 1/3 octave to 1 octave. Embodiment 4 FIG. Further, the reference value of the data value of the first to fourth A / D converters is set to １ ／ of the maximum value of the A / D conversion data. However, as a data value other than １ ／ of the maximum value, , 1 / of the maximum value of the data value of the A / D converter
Any data value such as the data value 3 may be used. Embodiment 5 FIG. In order to further improve the S / N of the source signal, one of the plurality of attenuators may be set to 0 dB when adjusting the system. This will be described with reference to FIG. FIG. 4 is a part of a flowchart showing a system adjustment program stored in the memory of the microcomputer. For example, steps 21 and 22 in the flowchart of FIG.
Insert between In step 41, the switching circuit 16 for switching between the band noise and the source signal is selected from the output circuit 13 of the microcomputer 9 for the band noise, and the first to fourth attenuators 2a, 2b, 2c, and 2d are respectively selected. First, it is set to 0 dB (output maximum). Next, at step 42, the data values of the first to fourth A / D converters 8a, 8b, 8c, 8d are read, and the smallest data value is determined. Then, the data value determined in step 43 is stored, and is used as a reference data value for determination in steps 23, 26, 29, and 32. Embodiment 6 FIG. In the above-described embodiment, the description has been made on the assumption that there are four channels as the system adjustment. , Etc., the same effect can be obtained. The band noise and the bandwidth of the band-pass filter are large when the number of channels is small,
When the number of channels is large, the number may be reduced. further,
Eliminate the A / D converter and add A / D to microcomputer
It goes without saying that the same effect can be obtained even if a converter having a built-in converter is used. According to the present invention, there is provided the structure as described above.
From the speakers, and the reproduced sound
Is divided into different bands by the microphone
Filter with multiple bandpass filters
The value obtained by rectifying the signal divided into
So that the playback output sound pressure level of each speaker is
Output sound of the sound reproduced from each speaker
The pressure level can be adjusted easily and quickly. [0027]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a system adjustment device showing one embodiment of the present invention. FIG. 2 is a flowchart showing a control program of a system adjustment device stored in a memory of a microcomputer. FIG. 3 is a block diagram showing a part of a system adjustment device according to another embodiment of the present invention. FIG. 4 is a flowchart showing a part of a system adjustment program stored in a memory of a microcomputer according to another embodiment of the present invention. [Description of Signs] 1a First band noise 1b Second band noise 1c Third band noise 1d Fourth band noise 2a First attenuator 2b Second attenuator 2c Third attenuator 2d Fourth attenuator 3 Amplifier 4 Speaker 5 Microphone 6a First band pass filter 6b Second band pass filter 6c Third band pass filter 6d Fourth band pass filter 7a First rectifier circuit 7b Second rectifier circuit 7c Third rectifier Circuit 7d Fourth rectifier circuit 8a First A / D converter 8b Second A / D converter 8c Third A / D converter 8d Fourth A / D converter 9 Microcomputer 10 CPU 11 Memory 12 input circuit 13 output circuit 14 start switch 15 display LED

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04S 7/00 H04R 3/04 101

Claims (1)

(57) and a plurality of band noise from the plurality of band noise generator with Patent Claims 1] each Re their Re different bands, a switching circuit switching by selecting a plurality of source signals A plurality of attenuators for adjusting the level of the plurality of band noises or source signals; and simultaneously reproducing the plurality of band noises from the respective speakers via the plurality of attenuators to reproduce reproduced sound. Sound is collected by a microphone,
A band-pass filter that divides the collected signal into a plurality of different bands, a rectifier circuit that rectifies the signals divided into the respective bands, and an A / D converter that converts the rectified signal into digital data. as the value of the digital data a / D converter are the same, the system adjusting apparatus comprising control means for controlling the attenuator to adjust the level of the rectified signal.