JPS5919520Y2 - Reverberation adding device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a reverberation adding device that adds reverberation to a stereo second channel signal, and when applied to a stereo source, especially a source where the singer is localized at the center of the speaker, the reverberation adding device adds reverberation to a stereo second channel signal. By adding reverberation, it is possible to reduce the echo feeling and changes in sound image localization, allowing normal natural playback, and adding desired reverberation to so-called ambient localization signals other than the central localization, resulting in stereo The purpose is to create a sense of spaciousness in the reproduced sound field.

FIG. 1 and FIG. 2 each show a conventional reverberation adding device.

In Figure 1, 1 and 2 are stereo signal input terminals, 3
is an adder.

This adder 3 is a circuit that adds the second stereo signals at the same phase and level to create a signal sum.

This sum signal is input to a reverberation generation device using a spring or a reverberation generation circuit 4 using a signal delay element such as a BBD (analog signal delay element).

The sum signal at this time includes the center localization signal and the surrounding localization signal at the same level.

(In general, the center localization signal level is distributed to each of the two channels at a level of -3 dB from the surrounding localization signal level, so that the reproduction level is the same during standard stereo listening.

) The center localization signal and the ambient localization signal are converted to reverberant signals at equivalent levels.

The reverberant signal is added in positive phase to one of the stereo signals in an adder 5, and the other signal is added in positive phase to the other one in the adder 6, and the direct signal and the reverberant signal are mixed and output to respective signal output terminals 7 and 8.
is output to.

In the conventional device shown in Figure 1, reverberation signals are uniformly added to both ambient sounds and center-localized sounds, and a considerable amount of reverberation is also added to singing voices (center-localized vocals). This results in a large change in the timbre of the reproduced sound of the signal that plays the central role of a stereo source.

In order to eliminate the drawbacks of the conventional example, a device shown in FIG. 2 has been proposed.

In this second conventional example, the adder 3 in the circuit shown in FIG. 1 is replaced with a subtracter 9, and the second stereo signal is the signal sum in FIG. In the example, subtractor 9
It is designed to take the signal difference.

In this signal difference configuration, the in-phase and same-level signals between the second stereo channels, that is, the center localization component (vocal), are completely canceled by the subtracter 9 and are not input to the reverberation generation circuit, and the center localization signal is This is an excellent device in that it adds reverberation only to the surrounding localization signal without adding reverberation to the signal, but on the other hand, it also has a configuration that emphasizes the signal difference component between the two channels.

Therefore, depending on the recorded contents of the stereo source, for example, on-mic recording with a small difference signal component and off-mic recording with a large difference signal component, the output signal level of the subtracter 9 will vary greatly, and the reverberation effect will add a sense of spaciousness to the sound field. This has the disadvantage that the settings are highly dependent on the stereo source.

The present invention provides a reverberation adding device that can eliminate the drawbacks of both the conventional examples shown in FIGS. 1 and 2,
An embodiment of the present invention will be described below with reference to FIG.

In FIG. 3, reference numerals 1 and 2 are stereo signal input terminals, one human input signal is directly input to the positive phase input terminal of the adder 3, and the other input signal is inputted to the adder 3 via a phase shifter 10.
is input to the positive phase input terminal of

This phase shifter 10 has a small amount of phase shift in the low frequency region of the input signal, and as it moves to a high frequency region, the amount of phase shift increases accordingly, and in a sufficiently high frequency region, it takes an extreme value of the desired set value - φ degrees. .

In this example, the phase shift amount limit value −φ is 1φ=-π This is what is set to.

To explain the stereo input signal characteristics in this case, when the output signal of adder 3 is inputted only to input terminal 2, an output signal proportional to the input signal is obtained; The signal is phase shifted by phase shifter 10 with respect to the input terminal signal phase according to the phase shifter settings.

However, the frequency characteristics remain unchanged and the signal is output from the adder 3.

In other words, the independent signals from each input signal terminal become the output signals of the adder 3 as they are, and become the input signals of the reverberation generating device 4 via the bypass filter 11.

Next, the output signal characteristics of the adder 3 in the case of an in-phase and same-level signal of a stereo signal, that is, a signal such as a singer's voice, are as shown in FIG.

In other words, if the effective value of the input signal level at input terminal 1 is B, and the effective value of the input signal level at input terminal 2 is C, then adder 3
The output signal level A is when the amount of phase shift is φ.

For in-phase and same-level signals from singers, etc., B=C, so if the extreme value of the phase shift amount is set to π as shown in Figure 4,
A=0, and no output is generated in the adder 3.

In this way, by passing the phase shifter 10 to one side of the adder 3 that adds the stereo signals, it becomes possible to give frequency characteristics only to the centrally located signal, such as a singer's signal.

The frequency characteristic of the embodiment shown in FIG. 3 has a low-pass characteristic as shown in FIG. 4.

In this case, the output level of the mid-low band signal becomes relatively high, and only the mid-low band signal of the center localization signal is output.

For this reason, in the present invention, a bypass filter 11 is inserted after the adder 3 to cut the attenuation, thereby forming a total band-pass filter characteristic.

By setting the phase shift characteristic of the phase shifter 10 and the cutoff frequency of the bypass filter to appropriate values in this way,
It becomes possible to set the frequency characteristics and signal level of the input signal to the reverberation generation circuit by the center localization signal to a narrow band and low level with a degree of freedom compared to the surrounding localization signal (signal from only one channel).

The output signal of the reverberation generating device 4 is added to the original input signal by adders 5 and 6, and becomes a reverberation-added signal, which is sent to the output terminal 7.
, 8.

FIG. 5 shows another embodiment of the invention.

In this embodiment, the output of the phase shifter 10 is inputted to the phase inverting terminal of the subtracter 9, and the frequency characteristics for stereo in-phase and in-phase levels are reduced to obtain a minimum value and a maximum value in the high range.
The output signal frequency characteristic of the adder 3 is opposite to that of the embodiment shown in FIG.

In this case, the insertion filter is a low pass filter 12.

The present invention has the above configuration, and according to the present invention, the following effects can be obtained.

(1) The amount of reverberation signal added to the singer's signal, which is the center localized component of the stereo signal component, can be made smaller than the surrounding localized component, resulting in a wider sound field with less change in the singer's timbre. You can get a sensory effect.

(2) Reverberation addition effects can be obtained mainly on the playback side without being affected by the recording situation of the stereo signal.

(3) By using the phase shifter and the filter circuit, there is a degree of freedom in setting the frequency characteristics and signal level of the human input signal to the reverberation generation circuit, and the effect setting of the reproduced sound field can be arbitrarily set.

[Brief explanation of drawings]

1 and 2 are block diagrams of conventional reverberation adding devices, FIG. 3 is a block diagram of a reverberation adding device according to an embodiment of the present invention, and FIG. 4 shows the amount of phase shift of the phase shifter of the same device. A diagram showing the frequency characteristics and the frequency characteristics of the output signal of the adder,
FIG. 5 is a block diagram of another embodiment of the present invention. 1.2...Input terminal, 3...Adder,
4... Reverberation addition circuit, 5, 6... Adder, 7, 8... Output terminal, 9... Subtractor, 10... ... Phase shifter, 11 ... Bypass filter 12 ... Low pass filter

Claims (1)

[Scope of utility model registration request] A phase shifter that increases the phase shift amount of one input signal of a second stereo channel signal as it transitions from a low frequency region to a high frequency region or as it transitions from a high frequency region to a low frequency region; means for adding or subtracting the output and the other input signal of the stereo second channel signal; a bypass filter or a low-pass filter for attenuating the low or high range of the addition side signal or subtraction signal of the addition or subtraction means; a reverberation adding means for adding reverberation to the signal passed through the filter; and a first reverberation adding means for adding reverberation output of the reverberation adding means to each input signal of the stereo second channel signal. A reverberation adding device comprising a second adder.