JPS6019200B2 - Reverberation sound addition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-channel sound reproduction device, by artificially adding residual sound, to obtain the same sensation as a live performance in a concert hall while being in the reproduction sound field. This invention was invented to add special effects to the music being played by changing the residual amount or changing the residual amount.

Conventionally, as this type of device, for example, there are devices that simply delay signals using signal delay elements such as springs, pipelines, bucket brigades, so-called BBDs, etc.
On the other hand, there are some methods that try to obtain the above reverberation effect using very complicated methods, but the former's effect is insufficient;
Furthermore, the latter was considerably larger and moreover expensive to manufacture, making it unsuitable for incorporation into home stereo equipment. The present invention aims to improve these drawbacks and provide a device that has a relatively simple configuration, can be easily incorporated into a commercially available sound reproduction device, and can sufficiently exhibit the above-mentioned effects.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

As shown in Fig. 1, when listening to the sound generated by a single sound source 1 on the stage in a closed actual sound field space such as a concert hall, the I'll be listening to Tatsumi-haired, Serpent, Clouded, and Kotowarataka later.

Here, the reflected sound that reaches listener 2's ear first is called the first reflected sound, but this first reflected sound also undergoes further reflection and becomes the second reflected sound.
The reflected sound reaches the listener's ears from the direction opposite to that of the first reflected sound. It is also thought that higher-order reflected sounds sequentially reach the listener's ears while changing their arrival direction in various ways and gradually attenuating. Therefore, when adding reverberant sound, it is conceivable that effective reverberant sound can be obtained by synthesizing reverberant signals that approximate the actual sound field as much as possible. That is, when synthesizing reverberant sound, it is necessary to consider the direction of arrival of the reverberant sound.

Figure 2 shows the basic configuration of this invention.
EL is, for example, a signal delay element such as a pipeline, a spring, or a bucket-loaded shift register, or an ATT.
・R and ATT・L are attenuators that are interlocked with each other and change the amount of coupled transmission between the signal delay elements DER and DEL.

A.A is a summing amplifier which has the function of adding and amplifying a plurality of signals. Note that in this case, a simple adder without an amplification function may be used. The system shown in this figure is applied to a two-channel stereo playback device, and a right signal and a left signal are respectively added as inputs. In other words, the signal applied to the R input is subjected to a time delay by the delay element DER, and then mixed with the original signal at an appropriate ratio to become the R output.
After attenuating through T and L, it is mixed with the L input, delayed by the delay element DEL, mixed with the L original signal, and the L
becomes part of the output.

Similarly, for the L input, the R signal and the L signal are mixed while being attenuated in a delay loop constituted by delay elements DER and DEL, and are taken out in a mixed state with the R output. That is, reverberation signals having various delay time directivities are added to the R signal and the L signal. Since the R signal and L signal are mixed here, there is a question as to whether this may affect the localization of the blue sky in the reproduced sound field. , and when two separately placed sound sources are made to produce instantaneous sound with a time difference, it has been found that the sound image is localized to the one that produces the sound earlier. By the way, all the mixed signals in this invention are emitted with a time delay from the original signals, and from the above fact, it is considered that they do not affect sound image localization.

In addition, in order to obtain the same effect for each of the R signal and L signal, the delay elements DER and DE must be
L must have the same properties. FIG. 3 shows the basic internal configuration of delay elements DER and DEL. DL1, DL2, and DL3 are unit delay elements, respectively, and a feedback loop is provided at the input from each straw point. It creates reverberant sound due to distance reflection.

In this case, a more natural echo pattern can be obtained if the delay time amounts set for the delay elements DL1, DL2, and DL3 are different from each other. That is, when the delay time amounts of each delay element are equal, an unpleasant flutter sound occurs, which is not preferable. In addition, in FIG. 2, the connection point 3 in FIG. 3 is used as an output, and it is configured to be added to the other input, but this is optional. When the power is on, the connection point n may be used as an output and the other input may be used, or a combination thereof is also possible.

Of course, in this case, the subjective feeling of the reproduced sound field will also differ depending on the subsequent method. FIG. 4 shows a more specific embodiment of the present invention, in which a bucket pregated shift register is used as a unit delay element,
This is configured for a two-channel playback device, and the amount of delay time can be freely changed depending on the applied clock frequency. That is, in the figure, 1.F is an input filter, and in order to prevent unnecessary cross modulation and distortion from occurring in delay elements DL1 and DL2, delay element DLI\D
The purpose is to pass only the frequency band that can be transmitted in L2.

M and F are intermediate filters, and since the clock frequencies used for DLI and DL2 are different, the delay element DL is set so that unnecessary beats between clocks do not occur in the delay element DL2.
This is for removing the clock component superimposed on the signal at I. AM is an amplifier, and a delay element DL
1. This is for amplifying the signal level attenuated by DL2 to a sufficient level.

.largecircle..F is for removing the clock signal mixed into the signal in the delay elements DL1 and DL2, and at the same time removing cross-modulation distortion and noise. VCO1 and VC02 are voltage controlled clock oscillators that supply two-phase clock signals to delay elements DL1, DL2 and DL3, respectively. E
Q is an equalizer for correcting changes in frequency characteristics occurring in delay elements DL1 and DL2. A
TT is a fixed attenuator, ATT1, ATT2, ATT
3. ATT4 is a variable attenuator, and those with the same number can change the amount of attenuation in conjunction with each other.

Furthermore, in this embodiment, the contact 3 in the basic configuration diagram shown in FIG. 3 is used as the other input, the connection point 2 is used as the output, and the return loop from the connection point 1 is removed.

Further, in this embodiment, unit delay elements DL1, DL
2. Since a bucket brigade shift register with the same number of transfer stages is used in DL3, if the same clock frequency is used for all these elements, each signal delay time will be the same, causing an unpleasant flutter sound. For this reason, two clock signal generators whose oscillation frequencies can be arbitrarily set by the applied voltages are used, and the signal delay time in delay element DL2 is configured to be different from that in delay elements DLI and DL3. Note that this drawback is caused by the oscillator VCO
It can also be removed by applying a clock frequency modulation signal of about 3 to 10 days to I and VC02, and can also be used to create a special sound field by changing the level, waveform, and frequency of the modulation signal. I can do it.

5 and 6 show an embodiment in which the present invention is applied to a sound reproduction device having two or more reproduction channels, and FIG. 5 shows connections for three channels, and Figure 6 shows connections for 4 channels.

It will be understood from the above description that connection of four or more channels can be easily achieved by combining the configurations of the present invention. In the embodiment shown in FIG. 4, the band width that can be transmitted by the delay elements DL1, DL2, and DL3 is limited to HZ
The range of clock frequency that can be varied with C02 is 1 female HZ~
It is set to 3 dishes HZ.

Therefore, since the number of transfer stages of the bucket brigade is 512, the delay time of each unit delay element DL1, DL2, and DL3 can be changed within the range of 28.88 hsec to 8.6 hsec. As described above, the present invention attenuates the output signal of the signal delay element by a predetermined amount by an attenuation means that can arbitrarily vary the output signal, feeds it back to the input terminal of another channel, and connects the output terminal of this element to the original signal of each channel. Since it is connected to the circuit, the reproduced pseudophonic sound is gradually attenuated each time it is fed back by the feedback loop including the above-mentioned attenuation means, and the reverberant sound gradually disappears, which is close to nature, and the reverberation pattern can be obtained. At the same time, by appropriately varying the amount of attenuation, it is possible to obtain spacing close to the actual sound field without disrupting the localization of the sound field, no matter where the listener is located in the sound field. .

[Brief explanation of the drawing]

FIG. 1 is a plan view for explaining an actual sound field, and FIG. 2 is a block diagram showing the basic configuration of the present invention. 3 is a block circuit diagram more specifically explaining the connection between the delay element and the attenuator in FIG. 2, and FIG. 4 is a block circuit diagram showing one embodiment of the present invention.
FIGS. 5 and 6 are block diagrams showing application examples. D
L1, DL2, DL3...delay elements. Figure 3 Figure 1 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A reverberation sound adding device in a multi-channel sound reproduction device, comprising: a first delay means for delaying a signal from a first input terminal to obtain a first delay signal; and a first delay means for obtaining a first delay signal; a first adding means for adding and outputting a signal from a first input terminal and the first delayed signal; and a first adding means for delaying a signal from a second input terminal to obtain a second delayed signal. a second delay means for adding the signal from the second input terminal and the second delayed signal, and a second addition means for adding the signal from the first input terminal and the second delayed signal; a third addition means for adding the signal from the second input terminal and the first delay signal and inputting the output thereof to the first delay means; a fourth addition means input to the second delay means; the first and second delayed signals are each attenuated by a predetermined amount by the attenuation means which can arbitrarily vary the amount of attenuation; A reverberation sound adding device characterized in that the reverberation sound is fed back to the adding means.