JPH0540493A - Reverberation adding device - Google Patents

Abstract

PURPOSE:To offer the reverberation adding device which can obtain a reverberation sound having a spreading sense, in which coloration is small and density is high. CONSTITUTION:The device is constituted of a means 111L for generating the left channel reverberation sound RL, a means 111R for generating the right channel reverberation sound RR, a means 112L for calculating a feedback signal for returning to an SR, a means 112R for calculating a feedback signal for returning to an SL, a means 113L for adding the SL, and an output RR of the means 112R and inputting its output to the mean 111L, and a means 113R for adding the SR and an output RL of the means 112L and inputting its output to the means 111R. Also, a pre-mixing means 12 and a post-mixing means 13 are provided additionally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverberation adding device for giving a sense of realism to an audio reproduction sound, and in particular, by adding reverberation, it is possible to prevent only specific frequency sounds from being emphasized. Regarding the device.

[0002]

2. Description of the Related Art In recent years, a reverberation sound adding device has been proposed in order to improve the realism and sound field by digitally processing an audio signal due to the progress of digital elements (Japanese Patent Laid-Open No. 61-175695). In the reverberation adding device proposed in the above application, reverberation is obtained by applying an input signal to a plurality of delay circuits having different delay times in common and feeding back the combined output of these delay circuits to the input side. I have decided.

[0003]

However, the reverberation applying apparatus according to the above invention has the following problems. 1) Since the reverberation sound is added to the monaural signal in which the left and right signals are independently added or the left and right signals are added, the feeling of sound broadness is lacking.

2) It is necessary to install more delay circuits in order to reduce the coloration of the reverberant sound and increase the density of the reverberant sound. The present invention has been made in view of the above problems, and an object of the present invention is to provide a reverberation adding device that can obtain a reverberation sound having a wide feeling as well as a low coloration and a high density.

[0005]

FIG. 1 is a basic configuration diagram of a reverberation adding apparatus according to the present invention. That is, the first aspect of the invention is that the left channel reverberation sound generating means 111L for generating the left channel reverberation sound RL, the right channel reverberation sound generating means 111R for generating the right channel reverberation sound RR, and the outputs of the left channel reverberation sound generating means 111L. The left channel feedback means 112L for calculating a feedback signal for returning to the right channel signal SR based on the above, and the right channel reverberation sound generating means 1
Right channel feedback means 11 for calculating a feedback signal for feedback to the left channel signal SL based on the output of 11R.
2R, the left channel signal SL, and the output of the right channel feedback means 112R are added, and the output is input to the left channel reverberation sound generating means 111L.
13L, and a right channel adding means 113R for adding the right channel signal SR and the output of the left channel feedback means 112L and inputting the output to the right channel reverberation sound generating means 111R.

A second invention is a left channel adding means 11
3L and the right channel addition means 113R, the left channel signal phase gain adjustment means 121L for adjusting the gain and phase of the left channel signal SL, and the right channel signal phase gain adjustment for adjusting the gain and phase of the right channel signal SR. Means 121R, left channel signal mixed phase gain adjusting means 122L for adjusting the gain and phase of the left channel signal and supplying it to the right channel, and right channel signal for adjusting the gain and phase of the right channel signal and supplying it to the left channel. A mixed phase gain adjusting means 122R,
The front left channel adding means 123L for adding the output of the left channel phase gain adjusting means 121L and the output of the right channel signal mixed phase gain adjusting means 122R, and the output of the right channel phase gain adjusting means 121R and the left channel signal mixed phase gain. A premixing unit 12 including a front right channel adding unit 123R for adding the output of the adjusting unit 122L is installed.

In a third aspect of the invention, the left channel reverberation sound is supplied to the right channel after adjusting the gain and phase of the left channel reverberation sound after the left channel reverberation sound generation means 111L and the right channel reverberation sound generation means 111R. A mixed phase gain adjusting means 131L, a right channel reverberant sound mixed phase gain adjusting means 131R for adjusting the gain and phase of the right channel reverberant sound to be supplied to the left channel, and a left channel reverberant sound and right channel reverberant sound mixed phase gain adjustment. The rear left channel adding means 132L for adding the output of the means 131R and the rear right channel adding means 132R for adding the output of the right channel reverberation sound and the left channel reverberation sound mixed phase gain adjusting means 131L. The post-mixing means 13 is installed.

A fourth invention is a left channel reverberation sound generating means 111L and a right channel reverberation sound generating means 111R.
Are at least first-order non-recursive digital filters or at least first-order non-recursive digital filters cascaded in two or more stages. The fifth invention is
The left channel reverberation sound generating means 111L and the right channel reverberation sound generating means 111R are composed of at least a first-order cyclic digital filter or at least a first-order cyclic digital filter connected in parallel in two or more stages.

The sixth invention is a left channel feedback means 11
The 2L and right channel feedback means 112R are phase gain adjusting means capable of adjusting the gain and phase of the input signal. In a seventh invention, the left channel feedback means 112L and the right channel feedback means 112R are at least first-order low-pass digital filters for an input signal.

The eighth invention is a left channel feedback means 11
The 2L and right channel feedback means 112R are at least first-order band pass type digital filters for the input signal.

[0011]

In the first aspect of the invention, the left channel reverberation sound R
L is the right channel signal SR and the right channel reverberation RR
Is returned to the left channel signal SL, the regularity of the reverberant sound is reduced and the reverberant sound is given a feeling of spread. In the second invention, since reverberation is added to the signal obtained by mixing the left channel signal SL and the right channel signal SR, reverberation sound having different effects on the sound to be localized in the center and the sound to be localized in the surroundings. Is added.

In the third aspect of the invention, since the left channel reverberation sound RL and the right channel reverberation sound RR are mixed, a reverberation sound having a feeling of spaciousness can be obtained. 4th to 8th
In the invention, the digital filter can be provided with a predetermined frequency characteristic, and the reverberation characteristic of the reverberation adding device can be approximated to the actual reverberation characteristic of the hall.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a functional diagram when the reverberation applying apparatus according to the present invention is constructed by a DSP, and it is constructed so as to generate an initial reflection sound in addition to the reverberation sound. For example, a stereo sound source 201 which is a compact disc player
The left and right channel signals SL and SR output from the A / D converters 202L and 20L
After being digitized by 2R, it enters the DSP 210 and undergoes arithmetic processing to generate an initial reflected sound and a reverberant sound.

The generated initial reflected sound and reverberant sound are mixed as desired and output as left, right, front, and rear channel signals. Since the output signal of the DSP 210 is a digital signal, the D / A converters 203L and 2L are provided.
It is converted into an analog signal by 03R, 204L and 204R. D / A converters 203L and 203
The channel signals converted into analog signals by R, 204L and 204R are amplified by power amplifiers 205L and 205R, 206L and 206R, and output as left and right and front and rear channel sound effects.

FIG. 3 is a block diagram of a first embodiment of the first invention in which a non-recursive digital filter (FIR filter) is used as the reverberation generating means and a phase gain amplifier is used as the feedback means. It is composed of software. That is, the FIR filter 311L or 311R has n stages of unit time delay elements 11, 12 ... 1
n are connected in series.

Each unit time delay element 11, 12 ... 1n
The outputs of the gain elements 21, 22 ... 2n, 2 (n +
1) and is added by the addition element 31. Each delay time T of each time delay element 11, 12 ... 1n
₁ , T ₂ ... T _n are set arbitrarily. Figure 4 shows FIR
It is a characteristic diagram of a reverberation adding device using a filter,
(A) shows the impulse characteristics of the FIR filter alone,
(B) shows the reverberation addition characteristic of the entire apparatus.

[0017] That is, when the impulse signal is applied to the FIR filter, the gain elements 21 and 22, each delay time T _k
···················································································. If the feedback means 312L and 312R are phase gain amplifiers capable of gain adjustment and switching between positive and negative phases of output, the left channel F
The output of the IR filter 311L is the phase gain amplifier 312.
The output of the right channel FIR filter 311R is fed back to the right channel addition element 313R via L and to the left channel addition element 313L via the phase gain amplifier 312R.

Therefore, the left channel FIR filter 311
The addition signal of the L first output signal LR1 and the right channel signal SR is processed by the right channel FIR filter 311R and becomes the second output signal RR2 of the right channel FIR filter 311R. Further, the added signal of the second output signal LR2 of the left channel FIR filter 311L and the right channel signal SR is the right channel FIR filter 311.
Right channel FIR filter 311 processed by R
It becomes the R third output signal RR3.

Similarly, the right channel FIR 311
The fourth, fifth, ... Output signals are output from R. The same processing is performed on the left channel. In the reverberation adding device having this configuration, since the FIR filter processing is performed on the added signal of the reverberation sounds of the left and right channels and the right and left channel signals, the unit delay time for each channel is made relatively large. However, it is possible to obtain a highly dense random reverberation sound, that is, a reverberation sound with less coloration and a wider feeling.

FIG. 5 is a block diagram of the FIR filter used in the second embodiment of the first invention, in which at least two stages or more of the FIR filters 311L shown in FIG. 3 are cascade-connected. This makes it possible to increase the density of reverberation and increase the randomness.

As a reverberation sound generating means, a so-called cyclic digital filter (II
By applying the R filter), it is possible to obtain a reverberant sound having an equivalent effect with relatively few calculation steps. FIG. 6 is a block diagram of a third embodiment of the first invention, in which the feedback means 112L or 112R is
The case where it comprises with an IR filter is shown.

The feedback FIR filter 112L or 112R functions as a so-called low pass filter,
It is possible to cut components of reverberant sound above a predetermined frequency.
High-frequency reverberation is attenuated faster in a real concert hall, but by using a low-pass filter as the feedback means, it is possible to make the reverberation characteristics closer to those of a real concert hall. Become.

Further, if the feedback means 112L or 112R is a low-pass type filter in which a FIR filter and an IIR filter are connected in series, the number of adjustable parameters increases and the reverberant sound characteristics of a real concert hall can be more accurately simulated. It will be possible. Further, as the feedback means 112L or 112R, a low pass filter in which a FIR filter and an IIR filter are connected in series and a band pass filter in which a high pass filter in which a FIR filter and an IIR filter are connected in series are connected in series are used. You can also

FIG. 7 is a block diagram of an embodiment of the second invention.
The phase gain adjustment amplifiers 721L and 721R
Amplifier with a gain of 0.5 (g_L= G_R= 0.5) and mix
Gain the phase gain adjustment amplifiers 722L and 722R
0.5 phase inversion amplifier (g _L’= G_R’= -0.5)
And a reverberation adding device according to the first invention.
Is added to the storage.

For example, when a soloist song with an orchestra as a background is reproduced, when the reverberation adding device according to the first invention is applied, the reverberation sound is added not only to the orchestra but also to the soloist song to be localized in the center. The clarity of the soloist song is reduced. When the premixing circuit 72 according to the second aspect of the invention is used, no reverberation sound is added to the soloist song to be localized in the center, and no reverberation sound is added to the back orchestra. A more natural reproduced sound that maintains the intelligibility of is obtained.

Besides, the sound field feeling can be adjusted by appropriately adjusting the phases and gains of the phase gain adjusting amplifiers 721L and 721R and the mixed phase gain adjusting amplifiers 722L and 722R. FIG. 8 is a block diagram of an embodiment of the third invention, in which the reverberation sound mixed phase gain adjusting amplifiers 831L and 831R are phase inversion amplifiers (g _L ″ = g _R ″ = −0.5) with a gain of 0.5. ) Is added to the reverberation adding device according to the first aspect of the invention.

As a result, the reverberant sounds of the left and right channels are mixed in antiphase, and a reverberant sound with a more expansive feeling can be obtained.

[0028]

According to the first aspect of the present invention, it is possible to obtain a reverberant sound with high density and large randomness, and it is possible to generate a more natural reverberant sound. According to the second invention,
It is possible to prevent the intelligibility of the sound localized in the center from being lost.
According to the invention, it is possible to further increase the feeling of reverberation spread.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a reverberation adding device according to the present invention.

FIG. 2 is a functional diagram in the case of being configured by a DSP.

FIG. 3 is a configuration diagram of a first embodiment of the first invention.

FIG. 4 is a characteristic diagram of a reverberation adding device using an FIR filter.

FIG. 5 is a configuration diagram of a second embodiment of the first invention.

FIG. 6 is a configuration diagram of a third embodiment of the first invention.

FIG. 7 is a block diagram of an embodiment of the second invention.

FIG. 8 is a block diagram of an embodiment of the third invention.

[Explanation of symbols]

111L, 111R ... Reverberation sound generating means 112L, 112R ... Feedback means 113L, 113R ... Addition means 12 ... Premixing means 121L, 121R ... Channel signal phase gain adjusting means 122L, 122R ... Mixed signal phase gain adjusting means 123L, 123R ... Pre-addition means 13 ... Post-mixing means 131L, 131R ... Reverberation sound phase gain adjusting means 132L, 132R ... Post-addition means

Claims (8)

[Claims] 1. A left channel reverberation sound generating means (111L) for generating a left channel reverberation sound, a right channel reverberation sound generating means (111R) for generating a right channel reverberation sound, and the left channel reverberation sound generating means (111L). ) To return to the right channel signal based on the output of the left channel feedback means (112L), and to output to the left channel reverberation sound means (111R) based on the output of the left channel signal Right channel feedback means (112R) for calculating the feedback signal of the left channel signal and the right channel feedback means (112R)
R) output and add the output to the left channel reverberation sound generating means (111L), the left channel adding means (113L), the right channel signal and the left channel feedback means (112).
A reverberation adding device including a right channel adding means (113R) for adding the output of L) and inputting the output to the right channel reverberation sound generating means (111R). 2. A left channel signal phase gain adjusting means (121L) for adjusting the gain and phase of the left channel signal, and a right side before the left channel adding means (113L) and the right channel adding means (113R). Right channel signal phase gain adjusting means (121R) for adjusting the gain and phase of the channel signal, left channel signal mixed phase gain adjusting means (122L) for adjusting the gain and phase of the left channel signal and supplying the same to the right channel, Right channel signal mixed phase gain adjustment means (122R) for adjusting the gain and phase of the right channel signal and supplying the same to the left channel, the output of the left channel phase gain adjustment means (121L) and the right channel signal mixed phase gain adjustment Means (122
R) and the output of the front left channel adding means (1
23L), the output of the right channel phase gain adjusting means (121R) and the left channel signal mixed phase gain adjusting means (122).
Front right channel adding means (1
23R), and the reverberation adding apparatus according to claim 1, further comprising a premixing unit (12). 3. The left channel reverberation sound generating means (111)
L) and the right channel reverberation sound generation means (111R), and the left channel reverberation sound mixed phase gain adjustment means (131L) for adjusting the gain and phase of the left channel reverberation sound and supplying the same to the right channel; Right channel reverberation sound mixed phase gain adjustment means (131R) for adjusting the gain and phase of the channel reverberation sound and supplying the same to the left channel, and outputs of the left channel reverberation sound and right channel reverberation sound mixed phase gain adjustment means (131R) And a rear left channel addition means (132L) for adding the following, and a rear right channel addition means (132R) for adding the right channel reverberation sound and the output of the left channel reverberation mixed phase gain adjustment means (131L). The reverberation adding apparatus according to claim 1, further comprising a post-mixing means (13) including the following. 4. The left channel reverberation sound generating means (11)
1L) and the right channel reverberation sound generating means (111)
The reverberation adding apparatus according to claim 1, wherein R) is at least a first-order non-recursive digital filter or at least a first-order non-recursive digital filter cascaded in two or more stages. 5. The left channel reverberation sound generating means (11)
1L) and the right channel reverberation sound generating means (111)
The reverberation adding apparatus according to claim 1, wherein R) is at least a first-order cyclic digital filter or at least a first-order cyclic digital filter connected in parallel in two or more stages. 6. The left channel feedback means (112L)
The reverberation adding apparatus according to claim 1, wherein the right channel feedback means (112R) is a phase gain adjusting means capable of adjusting a gain and a phase with respect to an input signal. 7. The left channel feedback means (112L)
2. The reverberation adding apparatus according to claim 1, wherein the right channel feedback means (112R) is an at least first-order low-pass digital filter for the input signal. 8. The left channel feedback means (112L)
The reverberation adding apparatus according to claim 1, wherein the right channel feedback means (112R) is an at least first-order bandpass digital filter for the input signal.