JPH0147080B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stereo reproduction device, and more particularly to a stereo reproduction device capable of adding a spacious reverberation.

In a car stereo system, because the position of the listener changes greatly, for example from the driver's seat to the passenger seat, asymmetrical listening is always required with respect to the left and right channel speakers installed on both sides of the front or rear. I get used to it. For this reason, car stereo devices are provided with a correction device that performs sound image localization correction.

FIG. 1 is a circuit diagram showing an example of a conventional localization correction device generally used, in which left and right channel signals (L, R) are added together in an adder 1. Also, the left and right channel signals (L, R) are
The signals are supplied to left and right channel speakers 4 and 5 via delay circuits 2 and 3, respectively. on the other hand,
In adder 1, left and right channel signals (L,
The signal to which R) has been added is attenuated by an attenuator 6 and then supplied to a center speaker 7.

In a stereo system having a localization correction device configured in this way, if the listener 8 is located, for example, between the right channel speaker 4 and the center speaker 7, the amount of attenuation in the attenuator 6 is reduced and the center Increase the output sound pressure of the speaker 7. In this way, the listener will be able to perform localization correction using the outputs of the right channel speaker 4 and the center speaker 7.

However, in the apparatus having the above configuration, although localization can be corrected, it is not possible to add expansive reverberation.

To solve this problem, for example, as shown in FIG. 2, reverberation is added by supplying the output signal of adder 1 to reverberation devices 9 and 10, and the output signal to which this reverberation is added is Reverberation speakers 1 are installed on both sides of the listener 8.
1 and 12, respectively.

However, the above configuration has a major drawback in that two additional reverberation speakers are required to add reverberation.

An object of the present invention is to provide a stereo reproduction device that can easily add reverberation that gives a sense of spaciousness without adding speakers.

Hereinafter, the stereo reproduction device according to the present invention will be explained in detail using the drawings.

FIG. 3 is a main circuit diagram showing an embodiment of a stereo reproduction apparatus according to the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In the same figure, 13,
14 is an attenuator provided on the input side of the delay circuits 2 and 3, and 15 is a left and right channel signal L, R.
Adders 16 and 17 are adders 15 for inverting and adding
The first reverberation sound generation section 16 receives the outputs of (L+
R) The inverted direct sound component of the signal and the non-inverted 2
The second reverberant sound generating section 17 generates reverberant sound signals consisting of the following indirect sound components, and (L+R).
The inverted direct sound component of the signal, the inverted 2nd order, the non-inverted 3rd order, the inverted 4th order, and so on.
A reverberant sound signal consisting of an indirect sound component that alternately repeats inversion is generated. In this case, the first reverberation sound generating section 16 includes an adder 16a which receives the output signal of the adder 15 as one inverted addition input, and the adder 16a.
, an attenuator 16d that attenuates the output of the delay circuit 16c that delays the output of the inverting amplifier 16b, and uses the output as the other inverting input of the adder 16a, and an attenuator 16e. The output signal of the inverting amplifier 16b and the delay circuit 1
6c, and an adder 16f for calculating the difference with the output of 6c.

On the other hand, the second reverberation sound generating section 17 includes an adder 17a which receives the output signal of the adder 15 as one inverted input.
, a delay circuit 17b that delays the output of this adder 17a, an attenuator 17c that attenuates the output of this delay circuit 17b and supplies it to the other inverting input terminal of the adder 17a, and an attenuator 17d. The adder circuit 17e is configured to invert and add the output signal of the adder 17a and the output signal of the delay circuit 17b. 18 is the output of the attenuator 13 and the first
An adder 19 is an adder 1 that inverts and adds the output signal of the reverberant sound generating section 16 and the output signal of the attenuator 14.
8 is an attenuator that attenuates the output, 20 is a delay circuit 2
21 is an attenuator that attenuates the output of the second reverberation sound generator 17 and supplies it to the center speaker 7; 22 is a delay circuit; This is an adder that inverts and adds the output of the circuit 3 and the output of the attenuator 19 and supplies the result to the left channel speaker 5.

In the circuit configured in this way, first, the left and right channel signals are inverted and added in the adder 15, and the added output (-M) is supplied to the first and second reverberation sound generating sections 16 and 17, respectively. . Then, in the first reverberation sound generating section 16, the signal (-M) is inverted by an adder 16a, inverted again by an inverting amplifier 16b, and attenuated by an attenuator 16e to become a signal (-αM), The adder 16f outputs the inverted direct sound component. Next, when the delay time _T1 of the delay circuit 16c has elapsed, the signal (-M) supplied from the inverting amplifier 16b appears at the output of the delay circuit 16c, is input to the inverting terminal of the adder 16f, and the signal (- M) is attenuated by the attenuator 16d to become a signal (-αM), which is input to the non-inverting terminal of the adder 16f as a signal (-α ² M) via the adder 16a, the inverting amplifier 16b, and the attenuator 16e. . Therefore, the adder 16f
A signal [(1-α ² )M] is output as the next indirect sound component. Thereafter, the non-inverted indirect sound components of the third and subsequent orders are outputted every time _T1 in the same manner. Further, in the second reverberation sound generation section 17, the signal (-M) is inverted by the adder 17a to become the signal (M), attenuated by a predetermined amount by the attenuator 17d to become the signal (αM), and the signal (-M) is inverted by the adder 17e to become the signal (αM). The signal (-αM) is inverted and output as a direct sound component. Next, the output (M) of the adder 17a is output to the delay circuit 17b.
is delayed by a predetermined time _T1 , and the adder 17e
At the same time, the signal (-M) is attenuated by an attenuator 17c to become a signal (αM), which is inverted by an adder 17a, and further attenuated by an attenuator 17d to become a signal (-α ² M ) and is input to the other inverting terminal of the adder 17e. Therefore, the adder 17e outputs the signal [-(1-α ² )M] as the second-order indirect sound component. Furthermore, the output (-αM) of the adder 17a is transmitted to the delay circuit 17.
b and is input to the inverting terminal of the adder 17e, and the signal (-αM) is input to the attenuator 17c.
The signal is attenuated by the adder 17a and inverted by the adder 17a to become a signal (α ² M), which is attenuated by the attenuator 17d to become the signal (α ³ M) and input to the inverting terminal of the adder 17c. Therefore, the adder 17e is
Signal [α(1−α ² )M] as the third indirect sound component
Output. Thereafter, the fourth and subsequent indirect sound components are output in the same manner. Then, the first reverberation sound generation section 1
The output signal of 6 is sent to attenuator 1 in adder 18
The left and right channel signals (L, R) attenuated by signals 3 and 14 are inverted and added, respectively. Therefore, since the signal (αM) and the signal (-αM) are input as direct sound components in the adder 18, the direct sound components are canceled and not output, and the second and subsequent sound components supplied from the adder 16f are Only the indirect sound component is inverted and output. This indirect sound component is
is attenuated by a predetermined amount (β) by
It is input to one of the inverting terminals of 0 and 22. Since the right channel signal (αR) that has been attenuated by the attenuator 13 and delayed for a predetermined time by the delay circuit 2 is input to the other inverting input terminal of the adder 20,
Adder 20 receives the inverted right channel signal (-αR)
and the signal M ₂ [β(1−α ² )M] as the indirect sound, the signal
M ₃ [αβ(1−α ² )M], etc. are output, and these are supplied to the right channel speaker 4 to generate musical tones including reverberation. Further, the output signal of this attenuator 19 is sent to the left channel speaker 5 via an adder 22.
Similarly to the right channel speaker 4, musical tones containing reverberation are generated.

On the other hand, the output signal of the second reverberation sound generating section 17 is attenuated by the attenuator 21, and the signal m ₁ (-αβM) signal m ₂ [-(1-α ² )βM] signal m ₃ [αβ(1-α ² )M], etc., and is supplied to the center speaker 7. Therefore, the center speaker 7 first emits the signal m ₁ (-αβM) obtained by inverting the sum signal of the left and right channel signals as a direct sound component, and then the delay circuit 2,
The _inverted right channel signal (-
αR) and the inverted left channel signal (-αL) from the left channel speaker 5 are output as direct sound components. Next, center speaker 7
From the left and right _channel speakers 4 and ₅ , the signal M ₂ [(1
-α ² )βM], signal M ₃ [(1-α ² )αβM], etc. are sequentially output, and the center speaker 7 outputs a signal as an indirect sound component that alternately repeats inversion and non-inversion.
m ₂ [-(1-α ² )βM], signal m ₃ [(1-α ² )αβM]
etc. are output sequentially. As a result, a listener located between the right channel speaker 4 and the center speaker 7 or between the left channel speaker 5 and the center speaker 7 will hear reverberant sound with low correlation. This results in stereo sound with a large sense of expansion.

Note that the attenuators 13, 14, 16d, 16e, 17
c and 17d each have the same attenuation amount,
It is possible to manually adjust the amount of attenuation in conjunction with each other, thereby adjusting the time for which the reverberant sound remains. In addition, delay circuits 2 and 3
have the same delay time of, for example, 2 to 10 ms, and the delay circuits 16c and 17b have the same delay time of, for example, several tens of ms.
They have the same delay time of ms, and each delay time can be manually adjusted. Furthermore, attenuators 19, 2
1 have the same amount of attenuation, and the attenuation amount can be manually adjusted in conjunction with each other, thereby making it possible to correct the localization distribution. Also, attenuator 1
The output of 9 may be supplied to the inputs of delay circuits 2 and 3.

As described above, the stereo reproduction device according to the present invention has excellent effects in that localization distribution can be corrected and reverberation sound with a sense of spaciousness can be easily obtained without adding speakers.

[Brief explanation of drawings]

1 and 2 are circuit diagrams showing the main parts of a conventional stereo device, and FIG. 3 is a circuit diagram showing the main parts of an embodiment of the stereo reproduction device according to the present invention. 2, 3... Delay circuit, 4, 5... Left and right channel speakers, 7... Center speaker, 13, 14,
19, 21...attenuator, 15, 18, 20, 22...
Adder.

Claims (1)

[Claims] 1. A first adder that adds left and right channel signals, and a first reverberant sound generator that receives the output of this first adder and the left and right channel signals as input and generates a reverberant signal in which direct sound components are canceled. means and the first
A second reverberant sound generating means generates a reverberant sound signal including a direct sound component by inputting the adder output of , a stereo reproduction comprising a reverberation sound generation circuit comprising second and third adders respectively supplying the right channel speaker, and an attenuator for attenuating the output of the second reverberation sound generation means and supplying it to the center speaker. Device.