JPS6013640B2 - Stereo playback method - Google Patents

Description

Detailed Description of the Invention The present invention provides stereo reproduction that makes it possible to aurally and logically obtain sound field effects such as the reverberation and spaciousness of a large hall in a general room of about 6 tatami mats. Regarding the method.

The difference in physical quantity in sound reproduction between a general room and a large hall is the delay in the incidence of reflected sound and reverberant sound on the listener.

The relative bell ratio between the direct cost and the reflected sound that can be recognized by an intelligent person is
It is said to be about 12 MB, and in a general room, more than 80% of the signal energy of −2 B or more reaches the listener within 20 seconds from the direct cost arrival time. The reflected waves that give rise to a sense of intelligence, etc. are reflected waves with a time delay of 30 seconds or more, and it can be said that it is physically difficult to obtain a sense of resonance during stereo reproduction in a room.

Conventionally used methods for obtaining a sense of resonance include adding reverberation and simulating reflections using multiple speakers.

Zenikyo addition is a method of electrically creating reverberation sound by guiding an electrical signal to a reverberation addition circuit and adding the output signal to the original electrical signal.Also, the reflected sound simulation using a pair of multi-speakers can be performed indoors. This is a method in which a dozen or so speakers are arranged and a time-delayed electrical signal of the reflected sound that occurs when played back in a large hall is applied to each individual speaker.

Conventionally, reverberation has often been added using waveform attenuation caused by mechanical vibrations of springs, iron plates, etc.

In recent years, with the development of an electrical delay element BBD, it has become possible to obtain a residual signal electrically. The biggest problem with adding reverberation is that since addition processing is performed within the electrical signal circuit, a certain frequency of the original music signal may be electrically erased or emphasized before it is played back by the speaker due to the phase shift of the sound. This is something that you end up doing. In addition, as a psychological effect, since the reverberant sound is reproduced from the same direction as the direct sound, it is difficult to recognize the reverberant sound, and when the level of the reverberant sound is increased in order to recognize it, the reverberant sound is reproduced from the same direction as the direct sound. This has an adverse effect on sound quality, such as "muffled" and "blurred sound images." Conventionally, the method of simulating reflected sound has been to use the recording and playback of a tape recorder and create a delay time using multiple playback heads, but with the recent development of BBD, simulation has become possible. Ta.

However, it is difficult to put it into practical use because of drawbacks such as the need to provide as many loudspeakers as there are reflected sounds. The playback method according to the present invention is a two-channel playback with the same playback format as the main speaker and sub-speaker, and as other signals, reflected sound of 30 to 200 seconds is electrically generated, and two sub-speakers are used. This method reproduces reflected sound.

The signals added to each sub-speaker power are the L and R of the original music signal.
Monaural signal that combines channels, 30 to 200
5 to 8 based on the calculated attenuation slope up to sec.
This is a reproduction in which the reflected blue waves are randomly arranged within the above time. The attenuation gradient is preferably about a reverberation time of 1 sec. The reproduction level of the crab reflection sound varies depending on the type of music, and for classical music, the level of the initial electric reflection sound is -1 compared to the direct sound, and for popular songs, it is -13B.
The arrangement of the sub-speakers is symmetrical 600 in the front or 9 on the side.
The effect is maximized by setting it near either 0o or rear 6b.

The method of applying the signal to the sub-speaker is to apply the above composite signal to the right speaker, and to the left speaker, the signal is delayed by 20 seconds from the signal applied to the right speaker, and the same signal with the same attenuation gradient and arrangement of 50 to 220 seconds is applied to the left speaker. Apply.

The applied level at this time is a signal that is target B higher than that of the left speaker. The overall system configuration for implementing the method of the present invention will be described below with reference to the drawing of FIG.

In the figure, SIG is a stereo signal source, PAL, PAR
is preamplifier, MAL, MAR is main amplifier, MSL
, MSR is the main speaker, MIX is the preamplifier PAL,
An addition circuit that takes the output signal of P as an input signal, ATTo is an attenuation circuit that determines the amount of addition of the entire reflected sound, D,, ↑2,
D3...7n is a delay circuit, and 7, is 30
Around sec, 10, 2 173 10...7n
is around 200 seconds. ATT,,ATT2,A
TT3,......ATTn determines the attenuation gradient corresponding to each delay circuit, , 72, 78,...... The attenuation circuit MIX2 is an adder circuit that takes the output signals of the attenuation circuits ATT, ~ATL as input signals, MA is the main amplifier that takes the output signals of the adder circuit MIX2 as input signals, and M is the output signal of the adder circuit X2. The delay time Tn' is around the delay time of 20 seconds,
The main amplifiers SS, , SS2, which receive input signals via the main amplifier AMp, are sub-subikers. Fig. 2 shows the arrangement of the speakers in Fig. 1, with the counterfeit in a being symmetrical at 6 points in the front, the counterb in position b being at 90o from the side, and the counterfeit in c being in a position at 60o in the rear. The central counterfeit is the listener's counterfeit. The features and effects of the reproduction method of the present invention as described above are as follows:
'1' By setting the delay time of the reflected sound to 30 to 0 seconds (minimum and maximum range), there is little change in the sound quality of the direct sound due to the reflected sound, and the electric current before the time domain, where the echo is more than the echo, is Because it is a signal, there is little discomfort in the playback sound.

'2} By separating the speaker for reproducing reflected sound from the speaker for reproducing direct sound and arranging them at an angle, the level of reflected sound can be reduced and the effect on sound quality is small.
'3 By creating a time delay of around 20 seconds between the L and R channels of the Fukuda speaker, the reproduced reflected sound does not become monaural and the binaural correlation function is also lowered, increasing the sense of spaciousness. . Therefore, according to the stereo reproduction system of the present invention, it is possible to obtain sound field effects such as a feeling of reverberation and a sense of spaciousness comparable to those of a large hall even in the size of a general room.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the entire reproduction system for carrying out the stereo reproduction method according to the present invention, and FIG. 2 is a layout diagram of the same speakers. SIG...Stereo signal source, PAL, to P...
・・・Preamble, MAL, MAR... Main amplifier, MSL, hship R... Main speaker, skin X, . More than M2...
Addition circuit, ATTo, ATT,,...
...ATTn...attenuation circuit, 7,,72,...
...↑n, 7n...delay circuit, AM circle...amplifier, M
A,, MA2... Main amplifier, SS,, SS2...
...Secondary speaker. Figure 1 Figure 2

Claims (1)

[Claims] 1 comprising two main speakers and two width speakers, applying independent signals to each of the two main speakers,
The two sub-speakers include an adder circuit that adds the input signals of the two main speakers, a delay circuit and an attenuation circuit that output the output signal of the adder circuit for 30-200 msec with 5-8 waves, and one of the sub-speakers. The stereo reproduction method is characterized in that the signals are applied via circuits having a time difference of about 20 msec and a level difference of about 6 dB.