JP4045566B2 - Modulation effect device and electronic musical instrument - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a modulation effect device that generates a smooth waveform with a very low frequency.
[0002]
[Prior art]
In recent years, electronic musical instruments such as music synthesizers and electronic organs have become more and more digital and transparent. For this reason, the music played with these instruments cannot wipe out the unnaturalness. Therefore, various methods have been tried in music synthesizers and electronic organs to remove the artificial atmosphere, so-called electric odor, and make the sound natural. Therefore, it is desired to make a natural musical tone by adding a vibrato effect, a tremolo effect, a groul effect, etc. to an artificial musical tone signal emitted from an electronic musical instrument.
[0003]
Japanese Laid-Open Patent Publication No. 9-330081 discloses a random access memory that knows information for identifying a tone assigned to a sound channel as a storage device of an LFO in order to realize a vibrato effect corresponding to a tone color series such as a music synthesizer or an electronic organ. The effect information at a predetermined address position based on the tone color information is read out, and the effect is imparted to the tone of the channel based on the effect information.
[0004]
In Japanese Patent Application Laid-Open No. 8-146554, a modulation effect device for an electronic musical instrument divides a modulation signal period into a plurality of sections with an arbitrarily set division ratio, and each divided section has an arbitrary waveform shape. To generate a modulation signal. As a result, the waveform shape of the modulation signal is not monotonous, so that various effects can be imparted to the musical sound.
[0005]
[Problems to be solved by the invention]
Conventionally, as a modulation signal for imparting effects such as vibrato effect to the musical tone, a sine wave, sawtooth wave, ultra-low frequency of the waveform of the monotone shapes such as triangular wave it has been used. Thus, within certain long time, both the natural tone becomes periodic repetition was not Do Ikire.
[0006]
In particular, the vibrato effect of modulating a music synthesizer's VCO (voltage controlled oscillator) with an LFO (ultra-low frequency oscillator), the groll effect of modulating a VCF (voltage controlled filter) with an LFO, and the VCA (voltage controlled amplifier) as an LFO The tremolo effect was obtained by modulating with . However, all of them use a waveform of an oscillator in which the frequency and the amplitude are repeated regularly at a constant cycle, so that the tone becomes monotonous and unnatural. Therefore, the LFO waveform was further modulated and complicated, but the LFO was used, so it had periodicity and was basically monotonous.
[0007]
The present invention solves these problems, and provides a modulation effect apparatus and an electronic musical instrument that make a musical sound a natural musical sound by adding a vibrato effect, a tremolo effect, a groul effect, and the like.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in order to achieve the above object, the present inventor has completed the invention described below. In other words, the modulation effect device of the present invention includes a noise generator, a band pass filter, a modulator, a low pass filter, and an audio signal generator. The audio signal generator generates an audio frequency having periodicity. The modulator here is a balanced modulator or a ring modulator. The very low frequency is a frequency lower than the audible frequency and 0.01 to 50 Hz. The noise referred to in the present invention refers to white noise, colored noise and irregular noise. This band pass filter may be any filter that can pass audio noise . Therefore, it is possible to control the output ultra-low frequency waveform obtained by changing the transmission characteristic Q of the band pass filter. Therefore, when Q is small, the waveform becomes complicated, and when Q is large, it approaches a sine wave and becomes a monotonous waveform. Furthermore, the low-pass filter only needs to pass only the frequency component of the frequency difference between the audio signal and the audio noise signal .
[0009]
The method of generating an ultra-low frequency random waveform according to the present invention is as follows. First, noise is generated and input to a band-pass filter , and a first output signal that is audio noise passed through is taken out and applied to one of two inputs of a balanced modulator or a ring modulator. If you enter a longer audio signal is a second output signal of the audio signal generator to one input of the modulator, from the output of said modulator frequency of the first output signal and second output signal An output waveform including a signal having frequency components of the sum and difference is obtained. Further added resulting output waveform to a low pass filter to remove components of the sum frequency, extracts only the frequency component of the difference frequency. As a result, a very low frequency random waveform is obtained from the output. The present invention is a modulation effect device that imparts random “fluctuation” to a musical sound by modulating an effector such as an electronic musical instrument using an ultra-low frequency random and smooth waveform obtained by the modulation effect device. .
[0010]
By incorporating the modulation effect device into an electronic musical instrument, a musical sound modulated with a random and smooth waveform has no periodic repetition, and “fluctuation” is generated, resulting in a natural feeling. In other words, vibrato effect, tremolo effect, groul effect, etc. can be given to the musical sound generated from the electronic musical instrument, and it will heal the heart as music with transparency and naturalness.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below, but the present invention is not limited to them. Noise is generated by the above-described modulation effect device, this is added to the band pass filter, and the first output signal is applied to one of the two input terminals X of the balanced modulator or ring modulator. The second output signal of the audio frequency signal is added to the input terminal Y of the other modulator, and the first output signal and the two input signals which are the second output signal are output from the output terminal Z of the modulator. since the signal having the sum and difference of the frequency of the frequency component appears to remove the frequency components of the sum of the frequency of the two signals added them to a low-pass filter extracts only the frequency components of the difference in frequency between the both signals. A random and smooth ultra-low frequency signal can be obtained from the frequency component of the obtained frequency difference .
[0012]
The modulation effect device of the present invention is used in place of an ultra-low frequency oscillator used for an effector for generating a vibrato such as a music synthesizer or an electronic organ, a tremolo, a groul, etc., to obtain a natural sound. Used as a modulation effect device . Such a method smooth waveform at random that was generated in, there is no periodic repetition, it is generated "fluctuation" in the sound generated from the electronic musical instrument, the resulting tones of natural feeling.
[0013]
Next, FIG. 1 shows a block diagram of a modulation effect device for explaining a random waveform generation by a ring modulator and frequency control and amplitude control methods thereof. FIG. 1 shows a case where a ring modulator (RM) is used as a modulator. First, noise (white noise or colored noise) is generated by the noise generator NG , and the first output of the audio noise is passed through an audio bandpass filter (BPF) having a constant center frequency. The signal Fx is extracted and added to the input terminal X of RM. To the other input terminal Y, Fy which is a sine wave or triangular wave signal which is a second output signal from an audio signal generator whose frequency and amplitude can be varied is added. At this time, a signal having a frequency component of the sum and difference of the frequencies of the first output signal and the second output signal, which are (Fx ± Fy) , appears from the output terminal Z of RM.
[0014]
Here, the frequency component (| Fx − Fy |) of the absolute value of the frequency difference between Fx and Fy is calculated from the output of the above-mentioned RM, and both Fx and Fy frequencies are calculated so that it is a very low frequency signal. Set the difference closer . The output of this RM also includes the sum of the frequencies of Fx and Fy (Fx + Fy) at the same time. Therefore, as the LFO, the frequency component of the sum of the frequencies is unnecessary and is removed, and at the same time, a low-pass filter (Low Fx ) is used so that only the signal (| Fx − Fy |) that is the difference between the absolute values of the Fx and Fy frequencies can pass Pass Filter, LPF) is provided after the output terminal Z of the RM as shown in FIG. The absolute value is the difference frequency component of the frequency from the output of the thus LPF (| Fx - Fy |) and eject the. In this way , Fx, which is the frequency component of the audio noise that has passed through the BPF, and Fy, which is a frequency component such as a sine wave signal or a triangular wave, are the frequency components of the sum and difference of the frequencies from the RM output (Fx ± Fy ) appears, which frequency component is a difference between the absolute value of the frequency as the output is added to the LPF (| Fx - Fy |) randomly taken out smooth waveform of the very low frequency. The tone is modulated using this waveform.
[0015]
If changing the frequency at this time Fy, it is possible to control the smooth ultra low frequency signal at random the frequency component of the absolute value of the difference in frequency from the output of the LPF. Furthermore, if the output voltage of the sine wave at the RM input terminal Y is changed, the amplitude of the random signal can be controlled.
[0016]
An output control characteristic diagram of the modulation effect device is shown in FIG. The graph of FIG. 2a is a case where sine waves are used for Fx and Fy, respectively, for amplitude control of input and output. Figure 2a shows that when a sine wave Fy (210Hz) is input to the input terminal Y of the RM shown in Figure 1 and Fx (200Hz) is input to the other input terminal X, the output from the output terminal Z (Fx ± Fy ) Is obtained. The absolute value is the frequency component of the frequency difference between the frequency components of the sum and difference of the frequency of the output of the output terminal Z Ru is passed through a low-pass filter LPF and Fx and Fy with respect to a change in the voltage at the input terminal X that time ( The relationship with LFOoutput (10 Hz) obtained from | Fx − Fy |) is shown. This means that the amplitude of the obtained very low frequency signal LFOoutput can be controlled by the voltage at the input terminal X.
[0017]
Similarly, the graph of FIG. 2b is a graph in which the signals to be controlled when a sine wave is used for Fx and Fy in the amplitude control of input and output are interchanged. Fig. 2b shows that when a sine wave Fx (200Hz) is input to the input terminal X of the RM shown in Fig. 1 and a sine wave Fy (210Hz) is input to the other input terminal Y, the frequency is output from the output of the output terminal Z. Sum and difference frequency components (Fx ± Fy) are obtained. At this time, the output of the output terminal Z with respect to the change in the voltage of the input terminal Y is passed through the low-pass filter LPF, and the LFOoutput (10 Hz) obtained from the frequency component (| Fx − Fy |) which is the absolute value of the frequency difference . Showing the relationship. This means that the amplitude of the obtained ultra-low frequency signal LFOoutput can be controlled by the voltage at the input terminal Y.
[0018]
Figure 3a is the input terminal X of RM in FIG. 1, the output through the output of the noise generator NG to BPF (center frequency fc = 200Hz Q = 20) was added, the to the other input terminal Y Fy (210 Hz ) Is a frequency analysis of the output waveform (Fx ± Fy) of the output terminal Z using a spectrum analyzer. The frequency component of (Fx + Fy), which is the sum of the frequencies at this time , is distributed around 410 Hz. Further, the absolute value of the frequency difference between Fx and Fy (| Fx-Fy |) frequency components are distributed around the 10 Hz. The difference between the frequency of the ultra-low-frequency signal obtained when approaching the interval frequency Fx and Fy entered in this RM can be very small. Therefore, if the output waveform (Fx ± Fy) of the output terminal Z is passed through the low-pass filter LPF, the frequency component of (| Fx − Fy |) , which is the absolute value of the frequency difference with both signals as shown in FIG. It becomes a random spectrum distributed around 10Hz.
[0019]
【Example】
Specific examples of the present invention will be described.
[0020]
[Example 1]
The next waveform in Fig. 4a is the output of white noise from the noise generator NG in Fig. 1, and the Fx (Noise BPF Q = 20) of the waveform that appears when the BPF center frequency is 200Hz is the input terminal of the modulator RM. The waveform added to X is (a). The waveform obtained by adding Fy (Sin wave, f = 180 Hz, 5VP-P) from the other audio signal generator to the input terminal Y of RM is (b). Next, (c) shows a waveform in which (Fx ± Fy), which is the frequency component of the sum and difference of the frequencies of both signals Fx and Fy , appears from the output terminal Z of RM. By the low-pass filter from the output signal of the Z eliminate frequency components of the sum of unwanted frequencies (Fx + Fy), the frequency component of the absolute value of the frequency difference between Fx and Fy are | - | a (Fx Fy) A random and smooth waveform (d) was obtained.
[0021]
[Example 2]
Next, FIG. 4b shows an embodiment in which the frequencies of Fx and Fy are changed as follows. The white noise is output from the noise generator NG, and the waveform when Fx (Noise BPF Q = 30) of the waveform that appears when the BPF center frequency is 1,000 Hz is added to the input terminal X of the modulator RM is (a). is there. The other input terminal Y to the audio signal generator Fy output waveform (Sinwave 980Hz 2VP-P) was added to the input terminal Y of RM waveform is (b). Next, (c) shows a waveform in which (Fx ± Fy), which is the frequency component of the sum and difference of both signals Fx and Fy , appears from the output terminal Z of RM . By the low-pass filter from the output signal of the Z eliminate frequency components of the sum of unwanted frequencies (Fx + Fy), the frequency component of the absolute value of the frequency difference between Fx and Fy are | - | a (Fx Fy) A random and smooth waveform (d) was obtained.
[0022]
[Example 3]
Further, FIG. 4c shows an embodiment in which the frequencies of Fx and Fy are changed as follows. The white noise is output from the noise generator NG, and Fx (Noise BPF Q = 30) of the waveform that appears when the BPF center frequency is 1,500 Hz is added to the input terminal X of the modulator RM. is there. The output waveform (Sinwave 1,480 Hz 2VP-P) of the audio signal generator Fy at the other input terminal Y is (b). The sum and difference frequency components of Fx and Fy are obtained from the output signal of Z , and the frequency component of the sum of unnecessary frequencies (Fx + Fy) is removed in addition to the low-pass filter, and the absolute frequency difference The frequency component of the value was (| Fx − Fy |) , and a random and smooth waveform (d) was obtained.
As shown in FIGS. 4a, 4b, and 4c, the random waveform of this method has a feature that a random and smooth waveform can be obtained, and is optimal for modulation of an electronic musical instrument or the like.
[0023]
[Example 4]
FIG. 5 shows a block diagram of a basic music synthesizer. By replacing the ultra-low frequency generator of the present invention with this LFO ultra-low frequency oscillator, the VCO frequency, VCF cutoff frequency, and VCA amplitude are also randomly modulated, resulting in natural vibrato effect, groll effect, tremolo effect Synthetic sound with "fluctuation" with The ultra-low frequency random signal obtained from the modulation effect device can give a natural “fluctuation” because the waveform, frequency, and amplitude of a musical tone signal such as a music synthesizer or an electronic organ can be controlled randomly and smoothly. it can.
[0024]
[Comparative Example 1]
By operating the keyboard shown in the figure, keyboard control voltage (KCV) is output and added to the VCO. A waveform containing a large amount of harmonics is output from the VCO, and this is added to the VCF to adjust the cut-off frequency of this filter so that the harmonic structure of the tone to be synthesized is obtained. The obtained harmonic overtone is added to VCA to create the amplitude change of the sound to be synthesized. Simultaneously with KCV from the keyboard, a GATE signal indicating the ON / OFF of the keyboard is output, adjusting the ADSR of the envelope generator to create an envelope such as rise, attenuation, hold, and reverberation. This controls the cutoff frequency in addition to the VCF produce a change in tone. It also controls changes in amplitude in addition to VCA. At this time, VCO is the frequency, VCF is the timbre, and VCA is the amplitude of the three elements. However, this was an unnatural sound with an artificial so-called electric odor.
[0025]
[Comparative Example 2]
Therefore, the LFO in the figure is added to the control terminal of the VCO and modulates the frequency at a very low frequency to obtain the vibrato effect. Next, the LFO is added to the control terminal of the VCF and modulates the cut-off frequency at a very low frequency to obtain a groul effect. The LFO is also added to the control terminal of the VCA, and the tremolo effect is obtained by modulating the amplitude at a very low frequency. Even so, the LFO waveform is periodically amplitude and the waveform repeats regularly, so the synthesized sound is monotonous and unnatural .
[0026]
【The invention's effect】
Since the present invention is configured as described above, the following effects are exhibited . By using the modulation effect device of the present invention, a modulation waveform having no periodicity can be obtained. Further, the frequency and amplitude can be arbitrarily controlled and set. Further, when the musical tone of the electronic musical instrument is modulated by this modulation waveform, the musical tone of the electronic musical instrument can be made to have a natural musical tone by giving a vibrato effect, a tremolo effect, a groul effect, and the like. By this modulation waveform to be set to an audible frequency below ELF tone has no turbidity, it deepens comfort.
[0027]
By incorporating the modulation effect device of the present invention into an electronic musical instrument, the musical sound modulated with a random and smooth waveform has no periodic repetition, and “fluctuation” is generated, resulting in a natural feeling, generated from the electronic musical instrument. Vibrato effect, tremolo effect, growl effect, etc. can be given to the music to be played, and heals the heart as music with transparency and naturalness. As described above, even a music synthesizer or an electronic organ can provide an electronic musical instrument with a natural musical tone by removing an artificial atmosphere, so-called electric odor.
[Brief description of the drawings]
FIG. 1 is a block diagram of a modulation effect device.
FIG. 2 is an output control characteristic diagram of the modulation effect device.
Figure 2 a is a sine wave Fx = 200 Hz in addition to the input of the X terminal of the RM, the other when also added sine wave Fy = 210 Hz at the input of the Y terminal, a sine wave is a signal Fx in the X-terminal shows = 10 Hz of very low frequency output voltage LFOoutlput | center frequency when the control voltage by the amplitude (Controlvoltage, CV) was variable | Fx-Fy. Fig. 2b shows that when a sine wave Fx = 200Hz is applied to the input of the RM X terminal and a sine wave Fy = 210Hz is applied to the input of the Y terminal, the control voltage (Control voltage, CV) can be varied according to the amplitude of the sine wave of Fy. The very low frequency output voltage LFOoutlput with the center frequency | Fx−Fy | = 10 Hz is shown.
3 is a diagram showing a frequency scan Bae Kutoramu obtained from the output terminal Z of the modulator.
Figure 3a, the output waveform of output terminal Z is Fx + Fy = 410Hz frequency component and the center frequency when random noise Fx = 200 Hz extracted from the BPF, the sinusoidal Fy = 210 Hz in addition to the respective inputs of RM | Fx- Fy | = shows the frequency scan Bae Kutoramu of the frequency components of 10Hz.
Figure 3b, the frequency components the frequency spectrum component is the absolute value of the resulting frequency difference obtained by the low-pass filter of FIG. 3a | shows a = frequency scan Bae Kutoramu to around the 10Hz | Fx-Fy.
[Figure 4] Randomly smooth from the waveform obtained by inputting the output of the noise generator NG to the BPF
Waveform diagrams up to very low frequencies are shown .
FIG. 4 a shows the waveform of Example 1. FIG.
(a) Audio frequency noise extracted from BPF from Noise (Fx = center frequency 200Hz)
(b) Sine wave (Fy = 180Hz)
(c) RM output waveform Fx ± Fy
(d) An ultra-low frequency laser in which the frequency component of the frequency difference is separated from the output of c by LPF.
Random noise waveform (| Fx−Fy | = 20Hz center frequency)
FIG. 4 b shows the waveform of Example 2.
(a) Audible frequency noise extracted from noise from BPF (Fx = center frequency 1,000Hz)
(b) Sine wave (Fy = 980Hz)
(c) RM output waveform Fx ± Fy
(d) Very low frequency run in which frequency components of frequency difference are separated from the output of c by LPF
Dam noise waveform (| Fx−Fy | = 20Hz center frequency)
FIG. 4 c shows the waveform of Example 3.
(a) Audible frequency noise extracted from noise from BPF (Fx = center frequency 1,500Hz)
(b) Sine wave (Fy = 1,480Hz)
(c) RM output waveform Fx ± Fy
(d) If the frequency component of the frequency difference is separated from the output of c using LPF
Random noise waveform (| Fx−Fy | = 20Hz center frequency)
FIG. 5 is a basic block diagram of a music synthesizer.
[Explanation of symbols]
NG; White noise or colored noise generator
BPF; Band pass filter (Audio filter with constant center frequency fc )
fc; BPF center frequency
Fx; input frequency X terminal of RM or the frequency of the first output signal
Fy; frequency of the audio signal generator ( same as the frequency of the second output signal )
RM; balanced modulator or ring modulator
X, Y; RM input terminal
Z; RM output terminal
Fx ± Fy; RM output signal
LPF; Low-pass filter
| Fx−Fy |; Frequency component of absolute value of frequency difference obtained by LPF
VCO; Voltage controlled oscillator
VCF; Voltage control type filter
VCA; Voltage controlled amplifier
ADSR; Rise, decay, hold, reverberation (envelope generator)
LFO; very low frequency oscillator
KCV; keyboard control voltage
GATE; Gate signal (Indicates keyboard ON / OFF)
Vibrato (Frequency modulation of musical sound by very low frequency)
Growl (modulation of overtones near the cutoff frequency of the filter by ultra-low frequencies)
Tremolo ( musical tone modulation by ultra-low frequency)

Claims (3)

Means for applying the output signal of the noise generator to a bandpass filter and applying the resulting first output signal and the second output signal of the audio signal generator to a balanced modulator or ring modulator;
Modulation effect comprising means for adding to the low-pass filter a signal having as a component the sum and difference frequencies of the frequency of the first output signal and the frequency of the second output signal obtained from the balanced modulator or ring modulator apparatus. Input noise to the input of the audio bandpass filter to one of the two input terminals of the balanced modulator or ring modulator, add the random audio signal passed through, and the audio signal to the other input terminal Is added to the output terminal of the modulator to obtain a signal having the frequency of the sum and difference of both signals as components, and the obtained signal is input to a low-pass filter and passed through. To generate a smooth ultra-low frequency random modulation waveform with only the difference frequency component . An electronic musical instrument comprising the modulation effect device according to claim 1 .

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