JPH07110691A - Musical sound synthesizing device - Google Patents

Abstract

PURPOSE:To reduce the cost by simplifying a process procedure and reducing memory capacity and to provide the electronic musical instrument which widens the range of a musical performance by freely setting the duration of a musical sound by a player. CONSTITUTION:A keyboard 1 detects the pitch of the musical sound, the strength of a touch, etc., and when the duration (attenuation characteristics) of the musical sound is set with a playing operation element 3 and the timbre of the musical sound is set with a timbre setting operation element 4, a control part 2 outputs a signal PITCH indicating the pitch of the musical sound, a signal indicating an attenuation rate (d), etc., on the basis of those pieces of information. The signal PITCH is supplied to a delay parameter generation part 5, which outputs a delay quantity signal indicating a delay time DLY. Further, the signal PITCH is supplied to an inverse conversion part 10 and the attenuation rate signal (d), on the other hand, is supplied to the negative side input terminal of an adder 7 and added to a value 1; and the adder 8 and adder 9 both perform arithmetic of 1-(1/p)*(1-d) and output gain signals indicating the gain (a) of a variable amplifier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone synthesizing apparatus provided with an automatic key scaling device for automatically performing key scaling in a so-called delayed feedback type sound source.

[0002]

2. Description of the Related Art Conventionally, a so-called delayed feedback type sound source has been proposed as a sound source for forming a desired tone waveform (see Japanese Patent Laid-Open No. 58-48109). FIG. 2 shows its schematic configuration.

In FIG. 1, reference numeral 101 denotes an excitation waveform generator for storing a basic tone waveform and generating the tone waveform. The excitation waveform generator 101 reads out from the stored tone waveforms. A signal WAVE for designating a musical tone waveform to be reproduced, and a signal TO indicating the strength with which the player plays the keyboard, etc.
UCH, a signal K instructing the output of the read tone waveform
When ON is input, the initial tone waveform is read and output according to these signals. The initial tone waveform thus output is added to the output from the variable amplifier 103 by the adder 102, and the addition result is supplied to the filter 104. The signal FC for controlling the filter coefficient is input to the filter 104, and the filter 104 outputs the signal F.
The addition result is filtered based on the filter coefficient determined by C to color the musical tone. The signal output from the filter 104 is taken out as a musical tone signal to the outside and fed back to the adder 102 via a feedback loop formed by the variable delay circuit 105 and the variable amplifier 103.

The variable amplifier 103 is for determining the loop gain and is basically for attenuating the fed-back signal. The gain a corresponding to the input gain signal (this value is Although it depends on the characteristics of the filter 104, the filter 104 has a gain of 1 (0d
In case of B), when the attenuated sound is generated, it is generally smaller than 1) and the signal from the variable delay circuit 105 are multiplied, and the adder 1
Output to 02. The variable delay circuit 105 delays the fed back signal by a delay time DLY corresponding to the input delay amount signal. The delay due to the variable delay circuit 105, strictly speaking, the filter 104
The pitch (frequency) of the musical sound is determined according to the delay amount including the delay due to.

In the electronic musical instrument described above, comparing the case of outputting a musical tone with a high pitch and the case of outputting a musical tone with a low pitch, the musical tone with a high pitch has a high frequency, so that the delay amount is reduced, while the low tone is low. Since the pitch tone has a low frequency, it is necessary to increase the delay amount. That is, in order to output a musical tone with a high pitch, the initial musical tone waveform passes through the feedback loop more times than with a musical tone with a low pitch. Therefore, the number of gains multiplied by the variable amplifier 103 is larger in the high pitch musical tone than in the low pitch musical tone, and if the same value gain is used, the high pitch musical tone is musical tone lower than the low pitch musical tone. This is because the duration of is shortened.

For example, to generate a tone of 440 Hz, 440 gain multiplications are performed per second, while to generate a doubled 880 Hz tone, 880 gain multiplications are performed per second. . Therefore, if the tone waveforms of the respective frequencies are generated with the same initial tone waveform and the same gain, the attenuation rate of the tone of 880 Hz is 440 Hz.
It doubles the musical sound of. That is, the attenuation rate doubles each time the pitch increases by one octave.

In order to solve this problem, a method of correcting a musical tone to be generated by setting a breakpoint so that the duration of the musical tone does not change extremely and the table data is corrected A method is used in which the gain value is changed according to the musical sound to be generated and the gain is flattened.

[0008]

However, in the above-mentioned conventional electronic musical instrument, the method of setting and correcting a breakpoint requires changing the point of time at which the breakpoint is set for each musical sound, which complicates the processing. , Meanwhile,
Even in the method of using table data, the gain value must be stored as table data for each musical sound, so that the memory capacity increases, resulting in an increase in cost. Furthermore, in the conventional electronic musical instrument, when the desired musical tone is designated, the gain value is set to a predetermined fixed value accordingly, so that the performer can freely set the duration of the musical tone. I couldn't.

The present invention has been made in view of the above problems, and simplifies the processing procedure, reduces the memory capacity to reduce the cost, and allows the performer to freely set the duration of the musical sound. It is an object of the present invention to provide a musical sound synthesizing device or an electronic musical instrument capable of expanding the range of performance.

[0010]

In order to achieve the above object, the present invention provides an excitation waveform generating means for generating an excitation waveform, and a variable delay means for delaying the excitation waveform by a desired delay amount,
A feedback loop is formed with a variable amplification means for attenuating the output waveform from the variable delay means by a desired amount of attenuation, the variable amplification means and the variable delay means, and the output from the variable amplification means is the excitation waveform generation means. Adding means for adding to the excitation waveform from, the first setting means for setting the desired delay amount, the second setting means for setting the attenuation characteristic of the tone signal output from the variable delay means, And a third setting means for setting the desired attenuation amount according to the set attenuation characteristic and the set delay amount.

[0011]

When the delay amount of the variable delay means is set by the first setting means and the attenuation characteristic of the tone signal is set by the second setting means, the attenuation characteristic and delay set by the third setting means are set. The attenuation amount of the variable amplification means is set according to the amount, and the excitation waveform from the excitation waveform generation means is delayed and attenuated by the feedback loop formed by the variable delay means, the variable amplification means and the addition means, and then generated. It is added to the excitation waveform and output as a musical tone signal.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In this embodiment, as a sound source for generating a musical sound,
The sound source of FIG. 2 described in the prior art is used.

First, the principle of the present invention will be described.

The fundamental pitch of the generated musical tone is set to p (Hz)
Then, assuming that the gain of the variable amplifier 103 in FIG. 2 is a (here, a filter or the like is designed so that a represents loop gain), the attenuation rate d (1 / se
c) is represented by the following mathematical expression (1).

D = a ^ p (0 <a <1) (1) When this is solved for a, the following mathematical expression (2) is obtained.

A = d ^ (1 / p) (2) Here, “^” indicates that the mathematical expression immediately after that is a power.

Therefore, if the "a" is used to perform key scaling for each musical tone to be generated, the above-mentioned problem can be solved, but if the accuracy is sacrificed, a key scaling device with a simpler processing is realized. can do.

In the equation (1), "a" is generally smaller than "1" but very close to "1" when the attenuated sound is generated. As described with reference to FIG. 2, since the initial musical tone waveform passes through the feedback loop formed by the variable amplifier 103 and the variable delay circuit 105 a large number of times, the duration of the musical tone must be reduced unless the gain is substantially equal to "1". Is too short to be realized as a musical sound.
Here, when a = 1-b is set, the mathematical expression (1) is expressed as the following mathematical expression (3), and "b" is "0".
Equation (3) can be approximated as Equation (4) below.

D = (1-b) ^ p (3) d = 1-p * b (4) When this equation (4) is solved for "b", the following equation (5) is obtained. When “a” is calculated based on the equation (5), the following equation (6) is obtained.

B = (1-d) / p (5) a = 1-b = 1- (1 / p) * (1-d) (6) The present embodiment is based on the principle described above. Is applied to electronic musical instruments.

FIG. 1 is a block diagram showing the schematic arrangement of an electronic musical instrument equipped with an automatic key scaling device according to this embodiment.

In the figure, reference numeral 1 denotes a keyboard, which detects a key depression state of a player and outputs pitch information, touch strength (velocity), and sounding request to the control unit 2. Further, the control unit 2 is connected to a performance operator 3 including a switch for setting the duration of the musical tone, that is, a decay rate and a switch for changing the pitch, and a tone color setting operator 4 for setting the tone color of the musical tone. The control unit 2 controls the parameters (signal WA
VE, TOUCH, KON) and other parameters (signals PITCH, TC, d) are output. Here, the signal PITCH is a signal representing the pitch of a musical tone to be output, and its value corresponds to "p" described in the above equation (1) and the like. Further, the signal TC indicates the tone color of a musical tone determined according to the key depression by the player and the tone color set by the tone color setting operator 4, and the signal d indicates the attenuation rate d set by the performance operator 3. It is the attenuation rate signal shown.

The signal PITCH is the delay time DLY of FIG.
Is supplied to the delay parameter generating unit 5 which generates a delay amount signal for controlling the signal, and is also supplied to the filter coefficient generating unit 6 which generates the signal FC which determines the filter coefficient in FIG. Further, the signal TC and the signal TOUCH from the keyboard 1 are also supplied to the filter coefficient generating section 6, and the filter coefficient generating section 6 outputs a signal FC for coloring musical tones in accordance with these three signals. Occurs and determines the filter coefficients.

Further, the signal d is supplied to the negative input terminal of the adder 7, and "1" is input to the positive input terminal of the adder 7.
Is supplied. "1" is also supplied to the positive input terminal of the adder 8. The output of the adder 7 is supplied to one input terminal of the multiplier 9, and the reciprocal of the signal PITCH is supplied to the other input terminal of the multiplier 9 via the reciprocal conversion unit 10. The output of the multiplier 9 is supplied to the negative input terminal of the adder 8, and the output of the adder 8 becomes a gain signal that controls the gain a in FIG. That is, the elements 7 to 10 are configured to perform the calculation of the mathematical expression (6).

The control unit 2 and the elements 5 to 10 described above
By supplying the signal generated by the above to the sound source of FIG. 2 as a parameter, it is possible to freely change the duration of the musical sound and further widen the range of performance. Further, since the desired gain a can be obtained from the attenuation rate d by the elements 7 to 10, the processing procedure is simplified, and the memory capacity is reduced by not using the table.
As a result, the cost can be reduced.

In the present embodiment, the duration of the musical tone is set as the attenuation rate d by the performance operator 3, but it is automatically determined according to the key press of the player and the tone color setting by the tone color setting operator 4. You may do it. At this time, the attenuation rate may be stored as table data and read out from the table data in accordance with key depression, tone color setting, and the like.

Further, in the present embodiment, the gain is obtained by the approximate expression of the expression (6), but strict key scaling is performed by performing the exponentiation operation shown in the expression (2). You may comprise. At this time, instead of the elements 7 to 9 in FIG. 1, a power calculation circuit that outputs the exponentiation using the attenuation rate d and the output (1 / PITCH) of the reciprocal conversion unit 10 as input signals may be used.

Furthermore, the gain a of the multiplier 103 is determined by the gain characteristic of the filter 104 or the coefficient FC.
May be corrected (correction is performed so that the loop gain maintains a desired value).

In this application example, each element is configured by hardware, but a DSP (Digital Signal Process) is used.
or) and a microprogram may be configured as software.

The method of generating the initial waveform output from the excitation waveform generator 101 of FIG. 2 may be any method such as a waveform memory reading method and an FM method. Furthermore, the initial waveform need not be a musical sound, for example,
It may be an output waveform of noise (random number) or various sensors (for example, impact sensor).

Furthermore, in the present embodiment, the present invention is used to control the duration of a musical sound, but the present invention is not limited to this. For example, an effector to which delay feedback is applied (for example, a resonance string effect or a resonance drum effect is used). It can also be used for the coefficient control of what is generated.

[0033]

As described above, according to the present invention,
Excitation waveform generating means for generating an excitation waveform, variable delay means for delaying the excitation waveform by a desired delay amount, variable amplification means for attenuating the output waveform from the variable delay means by a desired attenuation amount, and the variable A feedback loop is formed with the amplification means and the variable delay means, and an addition means for adding the output from the variable amplification means to the excitation waveform from the excitation waveform generation means and a first setting for setting the desired delay amount. Means, second setting means for setting the attenuation characteristic of the tone signal output from the variable delay means, and the desired attenuation amount according to the set attenuation characteristic and the set delay amount. Since the third setting means is provided, the processing procedure is simplified, the cost is reduced by reducing the memory capacity, and the performer freely sets the duration of the musical tone. An effect that it is possible to widen the width of the playing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an electronic musical instrument having an automatic key scaling device according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a conventional sound source that forms a musical tone waveform.

[Explanation of symbols]

 2 control section (third setting means) 3 performance operator (second setting means) 5 delay parameter generating section (first setting means) 7, 8 adder (variable amplification means) 9 multiplier (variable amplification means) ) 10 reciprocal conversion unit (variable amplification unit) 101 excitation waveform generation unit (excitation waveform generation unit) 102 adder (addition unit) 103 variable amplifier (variable amplification unit) 105 variable delay circuit (variable delay unit)

Claims (1)

[Claims] 1. Excitation waveform generating means for generating an excitation waveform, variable delay means for delaying the excitation waveform by a desired delay amount, and variable amplification for attenuating an output waveform from the variable delay means by a desired attenuation amount. Means, an addition means for forming a feedback loop together with the variable amplification means and the variable delay means, and adding the output from the variable amplification means to the excitation waveform from the excitation waveform generation means, and setting the desired delay amount. First setting means for setting, the second setting means for setting the attenuation characteristic of the musical tone signal output from the variable delay means, and the desired setting according to the set attenuation characteristic and the set delay amount. And a third setting means for setting an attenuation amount.