JPS5811800B2 - Sound image position measuring device for reproduced acoustic signals in multi-channel acoustic signal reproduction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the sound image position of a reproduced acoustic signal in a multi-channel acoustic signal reproduction device.

2. Description of the Related Art Conventionally, for example, when operating a two-channel acoustic signal reproducing apparatus, a phenomenon often occurs in which the sound image in a certain sound range of the reproduced sound is not fixed and the position of the sound image moves.

This phenomenon is caused by the sound pressure level and time difference between the left and right channel reproduction systems in that sound range.

Therefore, an acoustic signal of the same frequency, same level, and phase is added to the input side of the left and right channels of the two-channel acoustic signal reproducing device as described above, and the difference between the sounds reproduced by the acoustic signal reproducing device is quantitatively detected. It is necessary to eliminate the difference between the left and right channels in the reproduction system.

In such a case, in the conventional technology, it is common to mainly measure the reproduction systems of the left and right channels separately, and to determine the position of the sound image, in particular, audibly through a hearing test.

The present invention is capable of efficiently determining minute differences in amplification, frequency characteristics, phases, and other performance characteristics related to the reproduction system between channels in a multi-channel acoustic signal reproduction device, and in a state close to the actual operating state. It is an object of the present invention to provide a sound image position measuring device for a reproduced acoustic signal in a multi-channel acoustic signal reproducing apparatus, which allows the sound image position of a reproduction system to be determined numerically based on the measurement results.

The sound image position measuring device for the reproduced acoustic signal in the multi-channel acoustic signal reproducing device of the present invention includes two or more systems of supply means for supplying the audio frequency signal from the audio frequency signal generating means to the acoustic signal reproducing device of the system to be measured; converting means for collecting the sound waves reproduced by the acoustic signal reproducing device into at least two systems and converting them into electric signals separately; and phase difference detecting means for detecting a phase difference between the electric signals from the converting means. , a level difference detection means for detecting a level difference between the electrical signals from the conversion means; and an algebraic sum of the phase difference signal output from the phase difference detection means and the level difference signal output from the level difference detection means. The apparatus is characterized in that it comprises one stage of calculation for performing calculations and supplying the calculation output to an indicator, and the indicator indicates the position of the sound image.

Hereinafter, the present invention will be explained based on the drawings.

The figure is a block diagram showing an implementation f1 of the sound image measuring device used in the present invention.

In the figure, reference numeral 1 denotes a Yubiki audio frequency oscillator, and its output is applied to two signal transmission lines 2 and 3 of the two-channel acoustic signal reproducing device A, which is the system to be measured, as signals of the same frequency and the same level.

Both added signals are amplified by amplifiers 4 and 5, respectively, and are emitted from speakers 6 and 7.

an amplifier 10 that collects the sound pressure emitted from both speakers 6 and 7 by two directional microphones 8 and 9 arranged on the speaker directivity axis, converts it into an electrical signal, and amplifies it by amplifiers 10 and 11, respectively; The two signals amplified by 11 are applied to a level difference detector 12, which detects the level difference between both channels and causes an indicator 13 to swing.

(At this time, directional microphones 8, 9, amplifiers 10, 11
etc. are independent, and the two circuits have uniform characteristics.

) On the other hand, a part 5 of the output of the amplifier 10 enters the phase difference detector 14, and a part of the output of the amplifier 11 also enters the level difference corrector 1.
5 and is applied to the phase difference detector 14.

The phase difference detector 14 detects the phase difference and the indicator 16 is swung.

The level difference corrector 15 is for correcting the level difference between both channels, and is for correcting the level difference between the two systems of signals applied to the phase difference detector 14 to facilitate phase difference detection. be.

At the same time, part of the outputs of the amplifiers 10 and 11 are applied to the horizontal and vertical axes of the cathode ray tube oscilloscope 17 so as to draw a Lissajous waveform to monitor the phase difference.

Further, the output of the level difference detector 12 and the output of the phase difference detector 14 are added to an addition/subtraction amplifier 18 for addition/subtraction amplification.
The sound image position indicator 19 is operated by the output.

The level difference indicator 13 and phase difference indicator 16 use zero center, (+), (-) indicator types. For example, if the left channel level is high with the right channel as the reference, (-
), and conversely, if it is small, it is a (+) indication, and similarly for the phase difference, if the phase of the left channel is behind the right channel, it is a (+) indication, and if it is ahead, it is a (+) indication. (-) may be used as an instruction.

Similarly, the sound image position indicator 19 uses a zero center indicator, with the zero position as the center (sound image center position), and the (+) direction as the right direction (sound image right position).
By setting the direction as (-) left (sound image left position), the sound image position can be directly read.

Here, the output signal of the addition/subtraction amplifier 18, that is, the level difference signal detected by the level difference detector 12 and the phase difference detector 1
The reason why the sound image position is indicated by the sound image position indicator 19 indicating the output signal obtained by performing an algebraic sum operation on the phase difference signal detected in step 4 by the addition/subtraction amplifier 18 is as follows.

That is, when there is no level difference, the sound image is located on the side with the leading phase, corresponding to the phase difference, and when there is no phase difference, the sound image is located on the side with the greater level, corresponding to the level difference.

Therefore, according to the sound image position measuring device according to the present invention,
The phase difference and level difference between each channel of the multi-channel acoustic signal reproducing device that is the system under test can be measured efficiently and in a state close to the actual operating state, and the sound image position can be determined based on the audibility of the conventional hearing test. It has the advantage that it is possible to make a more accurate numerical judgment than the judgment of , and that the judgment standard can eliminate variations in judgment due to individual differences in auditory sensation.

[Brief explanation of the drawing]

The figure is a block diagram showing an example of the configuration of a sound image measuring device according to the present invention. 1...Sweep audio frequency oscillator, A...
System under test (2-channel acoustic signal reproducing device), 2, 3.
...Signal transmission line, 4, 5, 10, 11...
...Amplifier, 6.7...Speaker, 8,9...
...Directional microphone, 12...Level difference detector, 13,16°19...Indicator, 14
... Phase difference detector, 15 ... Level difference corrector, 17 ... Braun tube oscillograph, 1
8... Addition/subtraction amplifier.

Claims (1)

[Claims] 1. A signal generating means for generating an audio frequency signal; two or more supply means for supplying the audio frequency signal from the signal generating means to an acoustic signal reproducing device of the system under test; converting means for collecting sound waves into at least two systems and converting them into electric signals separately; phase difference detecting means for detecting a phase difference between the output electric signals from the converting means; and output electricity from the converting means. a level difference detection means for detecting a level difference between signals; and an algebraic sum operation of the phase difference signal outputted from the phase difference detection means and the level difference signal outputted from the level difference detection means, and an instruction to output the calculation. 1. A sound image position measuring device for a reproduced sound signal in a multi-channel sound signal reproducing device, comprising: arithmetic means for supplying a signal to a sound image position measuring device, and the sound image position is indicated by the indicator.