JP2004053635A - Sound effect device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To add an effect very similar to mechanical spring reverbation in an effect device for outputting an musical sound signal while adding the effect to an input musical sound signal. <P>SOLUTION: The sound effect device reproduces a "dispersion" of a musical sound signal generated while mechanically transmitting it via a spring by a dispersion processing part 202, reproducing by a loop processing part 209a "loop" of the musical sound signal making a round trip of the spring by being transmitted up to the end of the spring and reflected therefrom, further detecting an attack of the musical sound by an attack detection part 205 and varies the cut-off frequency of a low-pass filter in a filter part 203 as stated above, and thus reproducing the sound of "splat", a characteristic of spring reverbation at the time of attack, generated at the instant when the attack is transmitted to the spring. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an effect device for giving an effect to an input tone signal and outputting the effect.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an effect device that applies an effect to an input tone signal and outputs the effect is widely known, and as one type of such an effect device, an electronic reverb that imparts a reverberation effect to an input tone signal is known. Here, even before the development of electronic reverbs, mechanical reverberation devices using coil springs (springs), so-called spring reverbs, have become widespread. It is still very popular because it provides unique effects that are not available in the electronic reverb. However, if the spring reverb is remanufactured as it is, the cost is higher than that of the electronic reverb.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has as its object to provide an effect device that can provide an effect that has not existed as a conventional electronic reverb.
[0004]
[Means for Solving the Problems]
An effect device according to the present invention for achieving the above object is a dispersion apparatus for generating a distributed tone signal representing a tone repeated based on an input tone signal while the tone represented by the input tone signal attenuates at a predetermined first time interval. A distributed processing unit for performing processing, and a predetermined second tone signal represented by the distributed tone signal based on the distributed tone signal after the distributed processing performed by the distributed processing unit. A loop processing unit for performing a loop process for generating a loop tone signal representing a musical tone that repeats while attenuating at time intervals, and a distributed processing unit interposed between the distributed processing unit and the loop processing unit; A filter unit having a low-pass filter for performing a low-pass filtering process and having an adjustable cut-off frequency, and an attack of a tone represented by an input tone signal. Attachment detection section to be issued, and the cut-off frequency of the low-pass filter of the filter section is set to a first frequency corresponding to the level of the attack according to the detection timing of the attack in the attack detection section, and after the attack has passed , A filter control unit that changes the cutoff frequency to a predetermined second frequency higher than the first frequency.
[0005]
In the effect device of the present invention, the dispersion processing unit reproduces the 'dispersion' of the tone signal generated during mechanical transmission via the spring, and the loop processing unit reproduces the tone signal transmitted to the end of the spring. Is reflected at the end of the spring and the 'loop' of the tone signal reciprocating through the spring is reproduced, and the attack detection unit detects the attack of the tone and sets the cutoff frequency of the low-pass filter of the filter unit as described above. By changing, the sound of "pip" generated when the attack is transmitted to the spring, which is a feature of the spring reverb during the attack, is reproduced.
[0006]
Thus, according to the effect device of the present invention, an effect very close to that of a mechanical spring reverb is provided as compared with a conventional electronic reverb.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0008]
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the effect device of the present invention.
[0009]
The effect device 100 includes an operator 101 and a DSP (digital signal processor) 102.
[0010]
The operation element 101 is an operation element for setting a time in the loop processing unit 209 (see FIG. 2) configured by the DSP 102 according to an operation.
[0011]
Further, the DSP 102 generates an output tone signal by performing an effect imparting process on the input tone signal.
[0012]
FIG. 2 is a functional block diagram showing an effect giving process in the DSP 102 of the effect device 100 in FIG.
[0013]
The input tone signal is input to the distributed processing unit 202 and the delay processing unit 204.
[0014]
Here, the processing of the tone signal passing through the distributed processing unit 202 will be described first.
[0015]
The distributed processing unit 202 performs a distributed process of generating a distributed musical tone signal representing a musical tone which repeats while the musical tone represented by the input musical tone signal attenuates at a predetermined first time interval.
[0016]
In the present embodiment, the distributed processing unit 202 is configured by an all-pass filter having a delay line, a through line, and a feedback line. In this embodiment, the four-stage all-pass filters are connected in series to generate acoustic signals having a plurality of different delay times.
[0017]
FIG. 3 is a schematic diagram of a tone signal.
[0018]
Here, FIG. 3A schematically shows an input tone signal. Here, it is assumed that an impulse-like tone signal is input as shown in FIG. 3A.
[0019]
FIG. 3B shows the distributed tone signal generated by the distribution processing unit 202.
[0020]
When the impulse-like tone signal shown in FIG. 3A is input to the distribution processing unit 202 and the dispersion processing is performed by the distribution processing unit 202, the input tone signal as shown in FIG. A dispersed musical tone signal is generated while repeating. Here, this repetition period T1 is referred to as a first time interval.
[0021]
The distribution processing unit 202 reproduces that the musical sound mechanically transmitted via a so-called spring reverb spring is 'dispersed' as shown in FIG. 3B.
[0022]
The distributed musical tone signal obtained by the distributed processing unit 202 is next input to the filter unit 203. The description of the filter unit 203 will be given later, and here, the distributed musical tone signal obtained by the distributed processing unit 202 will be described. It is assumed that the input is passed to the loop processing unit 209 without passing through 203.
[0023]
In the loop processing unit 209, based on the input dispersed musical tone signal, the distributed musical tone signal is generated at a second time interval larger than the first time interval (period T1 shown in FIG. 3B). A loop process for generating a loop tone signal representing a tone that repeats while attenuating is performed.
[0024]
FIG. 3C is a diagram schematically showing the loop processing signal, and the distributed processing signal shown in FIG. 3B has a period T2 longer than the period T1 (this is referred to as a second time interval here). ).
[0025]
The loop processing unit 209 reproduces the reverberation effect of the spring reverb, which is imparted when a musical sound transmitted via a spring reciprocates while being reflected at an end of the spring. In the present embodiment, a comb filter and a delay line are incorporated in the loop processing unit 209, so that a specific frequency is rapidly attenuated while being attenuated, and a more realistic reverberation effect is provided. It is configured as follows.
[0026]
The second time interval (cycle T2) used in the loop processing unit 209 is set to be changeable by the operator 101 shown in FIG.
[0027]
Next, a filtering process in the filter unit 203 and a control method of the filtering process will be described.
[0028]
The filter unit 203 includes a low-pass filter including a state variable filter, and the filter unit 203 has a function of adding a unique sound to the spring reverb. The filter unit 203 includes a state variable filter and a bypass circuit. The control unit 207 controls the cutoff frequency of the state variable filter, and in the present embodiment, the resonance frequency Q and the output volume level. Here, by controlling the cutoff frequency, the Q, and the output volume level to change over time, an acoustic effect that occurs when the spring reverb is used is generated. In particular, a unique sound effect is added to the attack portion where the level of the input tone signal rises sharply.
[0029]
The input tone signal is input to the distributed processing unit 202 and also input to the delay processing unit 204. In the delay processing section 204, a delay for generating a control signal based on the input tone signal is performed by the delay line. The tone signal processed by the distributed processing unit 202 composed of an all-pass filter includes a predetermined delay time because it passes through a plurality of delay lines. Further, the delay due to the attack signal detection unit 205 is also considered. That is, the delay processing unit 204 adjusts the delay time of the control signal and the delay time of the acoustic signal from the distributed processing unit in order for the filter unit 203 to control the distributed musical tone signal from the distributed processing unit 202 by the control unit 207. Therefore, delay processing is performed in advance. It should be noted that the same operation is achieved even if the delay processing unit 204 is arranged at a stage subsequent to the control signal generation unit 206.
[0030]
The input tone signal delayed by the delay processing unit 204 is input to the attack signal detection unit 205. The attack signal detection section compares the input tone signal with a predetermined level and detects it as an attack, and outputs a pulse having a level corresponding to the input level and a predetermined time width. The attack signal detection unit 205 includes a peak hold circuit for detecting an attack.
[0031]
FIG. 4 is an explanatory diagram of the control signal generation process. The input tone signal (A), the attack detection signal (B) output from the attack signal detection unit 205, and the control signal generation unit 206 described below. The generated control signal (C) is shown.
[0032]
The attack detection signal in FIG. 4B is a signal output from the attack signal detection unit 205 and indicating that an attack has been detected. The timing on the time axis of the attack signal indicates the attack detection timing. The level indicates the strength of the attack.
[0033]
The attack detection signal in FIG. 4B is input to the control signal generation unit 206.
[0034]
The control signal generation unit 206 receives the attack detection signal shown in FIG. 4B, and generates a control signal having an attenuation curve corresponding to the signal level of the attack detection signal as shown in FIG. 4C. It is generated and supplied to the control unit 207.
[0035]
The control unit 207 receives the control signal shown in FIG. 4C generated by the control signal generation unit 208 and sends a low-pass filter composed of a state variable filter to the filter unit 203 to change the attack level of the input tone signal. Control according to.
[0036]
FIG. 5 is an explanatory diagram of the filtering process by the filter unit 203.
[0037]
In the filter unit 203, under the control of the control unit 209, the cutoff frequency in the low-pass filter configured as a state variable filter in the filter unit 203 is adjusted according to the level of the attack in accordance with the timing of the attack. The frequency is set to a frequency f1 of 1, and after passing through the attack, the cutoff frequency gradually increases to a predetermined second frequency f2 higher than the first frequency f1 according to the attenuation curve of the control signal in FIG. Change. Further, the Q value of the state variable filter changes with the change of the cutoff frequency, and the output volume level also changes. By doing so, the filter section 203 adds a sound effect of “pish” at the timing of the attack specific to the spring reverb.
[0038]
In this manner, in the present embodiment, the effect given by the spring reverb, including the sound effect unique to the spring reverb, is reproduced with high accuracy.
[0039]
【The invention's effect】
As described above, according to the present invention, an effect not provided by the conventional electronic reverb is provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an effect device of the present invention.
FIG. 2 is a functional block diagram showing an effect giving process in a DSP of the effect device of FIG. 1;
FIG. 3 is a schematic diagram of a tone signal.
FIG. 4 is an explanatory diagram of a control signal generation process.
FIG. 5 is an explanatory diagram of a filtering process performed by a filter unit.
[Explanation of symbols]
Reference Signs List 100 effect device 101 operator 102 DSP (digital signal processor)
202 Distributed processing unit 203 Filter unit 204 Delay processing unit 205 Attack signal detection unit 206 Control signal generation unit 207 Control unit 209 Loop processing unit

Claims (1)

A distributed processing unit for performing a distributed process of generating a distributed tone signal representing a tone repeated based on the input tone signal while the tone represented by the input tone signal attenuates at a predetermined first time interval;
On the basis of the distributed tone signal after the distributed processing is performed by the distributed processing unit, the tone represented by the distributed tone signal repeats while attenuating at a predetermined second time interval larger than the first time interval. A loop processing unit for performing a loop process for generating a loop tone signal representing a tone;
A filter unit having a low-pass filter that is interposed between the distributed processing unit and the loop processing unit and performs a low-pass filtering process on the distributed musical tone signal obtained by the distributed processing unit, and a cut-off frequency is freely adjustable.
An attack detection unit that detects an attack of a tone represented by the input tone signal;
The cut-off frequency of the low-pass filter of the filter unit is set to a first frequency corresponding to the level of the attack in accordance with the attack detection timing in the attack detection unit, and after passing the attack, the cut-off frequency, An effect device comprising: a filter control unit that changes the frequency to a predetermined second frequency higher than the first frequency.

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