JP2800816B2 - Music synthesizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone synthesizing apparatus that generates musical tones that change in the same manner as natural musical instrument sounds.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus for synthesizing a musical tone of a natural musical instrument by simulating a sounding mechanism of the natural musical instrument. As a musical sound synthesizer for a stringed instrument sound or the like, there is known a structure in which a filter simulating a reverberation loss of a string and a delay circuit simulating a propagation delay of vibration in the string are connected in a closed loop. I have. In such a configuration, for example, when an excitation signal such as an impulse is introduced into the closed loop circuit in response to playing a string,
This excitation signal circulates in a closed loop. In this case, the excitation signal makes a round in the closed loop for a time equal to the vibration period of the string, and the band is limited when passing through the low-pass filter. Then, a signal circulating in the closed loop is extracted as a tone signal of the stringed instrument. Such a musical tone
According to the synthesizing device , by adjusting the delay time of the delay circuit and the characteristics of the low-pass filter, it is possible to synthesize a musical sound somewhat close to a natural stringed instrument sound such as a plucked instrument sound such as a guitar or a percussion instrument sound such as a piano.

[0003]

In the above-described conventional tone synthesizer , if the excitation signal contains a periodic component having a length equal to or longer than the time required for the closed loop circuit to circulate, the signal diverges in a short time. This causes inconveniences such as stop of generation of musical tones. Such a phenomenon becomes conspicuous when the closed loop circuit has a relatively large loop gain, particularly when used in a range exceeding “1”. SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and even when an excitation signal includes a low-frequency component having a long cycle, a musical sound synthesizer capable of synthesizing a musical sound without any inconvenience. The purpose is to provide.

[0004]

The present invention provides a delay means for setting a delay time corresponding to a pitch of a musical tone to be generated.
A plurality of loop means , each having a cascade connection, and a loop
Signal inserted between the means and input to the next loop means
Characterized by comprising the low-frequency attenuation means for attenuating low-frequency components of the. Further, according to the present invention, the low-frequency component of the signal input to the next stage by the low-frequency attenuation means is attenuated, is input the low frequency attenuation is signal which has been subjected to the subsequent loop means
By repeating this operation, a musical tone is synthesized.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a musical tone synthesizer according to an embodiment of the present invention. In this figure, 6 is a performance operator such as a keyboard, and 7 is a musical parameter setting operator which sets musical parameters such as tone. , 8 are control units for controlling each unit of the apparatus.

Reference numeral 9 denotes an excitation signal generator. In the excitation signal generator 9, reference numeral 10 denotes a waveform generator for outputting a generation signal including abundant harmonics, and data WAV, which are output from the controller 8 and specify the generated signal waveform, respectively.
E. Input a key-on signal KON for instructing the generation timing of the generation signal and pitch data PITCH for specifying the pitch of the generation signal, and output a generation signal of a predetermined waveform.

Reference numeral 11 denotes a noise generator for generating a noise signal such as white noise, and 12 and 13 denote filters. The waveform generator 10 and the noise generator based on the coefficient data FLT ₁ and FLT ₂ output from the controller 8. A predetermined characteristic is given to each output signal of the unit 11. Multipliers 14 and 15 multiply the amplitude control signals AMP ₁ and AMP ₂ output from the control unit 8 with the output signals of the filters 12 and 13, respectively. An adder 16 adds the output signals of the multipliers 14 and 15 and outputs the sum as an excitation signal. In addition, 17
Is a filter, to impart a predetermined characteristic with respect to the output signal of the excitation signal waveform generation unit 9 on the basis of the coefficient data FLT ₃ output from the control unit 8. A multiplier 18 multiplies the amplitude control signal AMP ₃ output from the control unit 8 by an output signal of the filter 17.

In addition, a resonance unit 19 simulates a resonance phenomenon of a natural musical instrument, which is output from the control unit 8.
Data ALG indicating a combination (connection mode: algorithm) of a plurality of resonance elements (loop circuits) (described later) constituting the resonance unit 19, data MIX indicating a synthesis coefficient of an output signal of each loop circuit, and each loop circuit delay amount related data DLY _{n (n} = 1~4: hereinafter the same), a low-pass filter constituting each loop circuit (hereinafter, referred to as LPF) coefficient LPF _n of all-pass filter constituting each loop circuit (hereinafter, referred APF coefficients APF _n) of high-pass filter (hereinafter constituting each loop circuits, impart predetermined properties to the coefficient HPF _n and loop gain LG _n output signal of the multiplier 18 on the basis of each loop circuit as HPF) Then, the tone signal is output as a tone signal for each of the L and R channels. The above-described coefficient data FLT ₁ to FLT ₃ and the amplitude control signals AMP ₁ to AMP ₃
May be constant or change with time.

Next, FIG. 2 shows a block diagram of the configuration of the resonance section 19. In this figure, the resonance element control unit 20
Are multiplication coefficients m ₁₁ -m ₁₄ , m ₂₁ -m ₂₄ , m ₃₁ -m of the respective multipliers 22-37 (see FIG. 3) of the signal synthesizer 21 based on the data ALG output from the controller 8. and supplies the determined m ₃₄ and m ₄₁ ~m _44. In FIG. 3, 3
8 to 41 are adders. Thereby, the signal combining unit 21
Is the output signal of the multiplier 18 and a loop circuit 42 ₁ described later.
It combines the -42 _fourth output signal, the loop circuit 42 ₁ to 42
Supply ₄

In FIG. 2, reference numerals 42 _{1 to} 42 ₄ denote loop circuits (hereinafter referred to as LOOP) having the same configuration, and the detailed configuration is shown in FIG. In this figure, 43 is to prevent the low-frequency component of the input signal based on the coefficient HPF _n supplied from the control unit 8 via the resonance elements control portion 20 HPF, 44 an adder, 45 is resonant element controller 20 Is an LPF that blocks a high-frequency component of an input signal based on a coefficient LPF _n supplied from the control unit 8 via the control unit 8.

[0011] 46 will vary depending on the phase difference signal frequency of the input signal and the output signal on the basis of the coefficients APF _n supplied from the control unit 8 via the resonance elements control portion 20 APF, 47 are resonant element based on the data DLY _n supplied from the control unit 20 via the control unit 8 for delaying the input signal by a predetermined delay amount delay circuit (hereinafter, DE
Called LAY), 48 is a multiplier for multiplying the output signal of DELAY47 based on the loop gain LG _n supplied from the control unit 8 via the resonance elements control portion 20.

The resonance frequency pitch of each of the LOOPs 42 _{1 to} 42 ₄ is determined by the LPF which is a component in the loop.
45, the APF 46 and the DELAY 47 are determined by the sum of the respective delay times, that is, the total delay amount of the loop. Therefore, the DELAY 47 is considered in consideration of the delay characteristics of the filters (LPF 45 and APF 46) in the loop.
And set based on the amount of delay data DLY _n, for pitch control.

Further, in FIG. 2, reference numeral 49 denotes LOOP4.
By combining 2 _{1-42 4} output signal is a signal synthesizing unit for outputting as L and R channels, respectively of the tone signal,
The resonance element control unit 20 controls each multiplier 50 of the signal synthesis unit 49 based on the data MIX output from the control unit 8.
The multiplication coefficients k _{1L to} k _4L and k _{1R to} k _4R of .about.57 (see FIG. 5) are determined and supplied. Thereby, the multipliers 50 to 57 multiply the output signals of the LOOPs 42 _{1 to} 42 _{4 by} the multiplication coefficients k _{1L to} k _4R , respectively. In FIG. 5, reference numeral 58 denotes an adder for adding the output signals of the multipliers 50 to 53 and outputting it as an L-channel tone signal OUTL; and 59, an adder for adding the output signals of the multipliers 54 to 57 and outputting the R-channel tone. An adder that outputs the signal OUTR.

In such a configuration, first, the LOOP
The combination of 42 _{1-42 4} (connection mode: Algorithm)
When a certain data ALG is output from the control unit 8 to set the data ALG, the resonance element control unit 20 outputs the data ALG.
, Each multiplier 22 of the signal synthesis unit 21 shown in FIG.
Each multiplication factor of _{~37 m 11 ~m 14, m 21} ~m 24,
m _{31 to} m ₃₄ and m _{41 to} m ₄₄ are determined and supplied. Thereby, LOOPs 42 _{1 to} 42 ₄ are, for example, shown in FIG.
Algorithms (connection modes) as shown in FIGS. 7A to 7C, FIGS. 7A to 7C, and FIGS. 8A and 8B.

Further, when a certain data MIX is output from the control unit 8 in order to indicate the synthesis coefficient of the output signals of the LOOPs 42 _{1 to} 42 ₄ , the resonance element control unit 20 performs the processing shown in FIG. The multiplier coefficients k _{1L to} k _4L and k _{1R to} k _4R of the respective multipliers 50 to 57 of the signal synthesizing unit 49 are determined and supplied. As a result, LOO
P42 ₁ through 42 ₄ of FIG. 6 (a) ~ (c) , FIG. 7 (a) ~
(C) The output signals of the algorithms as shown in FIGS. 8 (a) and (b) are synthesized in various ways. As described above, the control unit 8 sends the data ALG and the data MIX
Is output, the LOOP42 ₁ to LOOP42 ₁ to
42 ₄ can be formed by combining great variety of.

Here, when synthesizing a high-quality tone with a certain sense of pitch, the control unit 8 outputs data ALG and data MIX, and outputs the LOOP 42 ₁ -LO of the resonance unit 19.
42 ₄ configuration, as shown in FIG. 9, a configuration which is cascaded LOOP42 ₁ and 42 _2. When the player depresses a key on the keyboard of the performance operator 6, for example, the key corresponding to the C sound, key data such as a pitch corresponding to the key is output from the keyboard. Further, an initial touch and an after touch of each key of the keyboard are detected by a touch input unit (not shown), and touch data indicating the strength of the touch is created and output.

As a result, the control unit 8 sets the LOOP42 ₁
And 42 as the _second fundamental frequency pitches both a frequency f _1, the key data corresponding to the note C, the loop gain LG ₁ and LG ₂ for touch data and tone color or the like, the coefficient LPF ₁ and LPF _2, coefficients APF ₁ and APF _{2 and} coefficients HPF ₁ and HPF ₂ are output.
A value obtained by subtracting the delay amount of the LPF 45 and the delay amount of the APF 46 from the phase delay amount of the entire loop (see FIG. 9) corresponding to the sound is output as the delay amount of the DELAY 47, so that the resonance element control unit of the resonance unit 19 is output. 20, LOOP42 enter these data ₁ and 42 ₂ each HPF43, LPF45, APF46, DELA
Y47 and a multiplier 48.

Next, the control unit 8, the data WAVE, the key-on signal KON and the pitch data PITCH and supplies to the waveform generating section 10 of the excitation signal generating portion 9, the coefficient data FLT ₁ and FLT ₂ respectively filters 12 and 13 And the amplitude control signals AMP ₁ and AMP ₂
Is supplied to multipliers 14 and 15, respectively. At this time, the amplitude control signals AMP ₁ and AMP ₂
The ratio of the output signal of the filter 2 is set to be larger than the output signal of the filter 13. Further, the control unit 8 includes a filter 17
Supplies the coefficient data FLT ₃ to the
Supplies the amplitude control signals AMP ₃ to.

As a result, the waveform generator 10 outputs the data W
A generation signal having a signal waveform specified by AVE is generated and output at a generation timing specified by key-on signal KON and at a pitch specified by pitch data PITCH. The generated signal is given a predetermined characteristic based on the coefficient data FLT ₁ in the filter 12, and then multiplied by the amplitude control signal AMP ₁ in the multiplier 14 and output.

On the other hand, a noise signal such as white noise output from the noise generator 11 is given a predetermined characteristic by the filter 13 based on the coefficient data FLT ₂ , and then the amplitude control signal AMP is output by the multiplier 15. _Two
Is multiplied and output. And multipliers 14 and 1
The output signals of No. 5 are added in the adder 16 and output as excitation signals.

Next, the excitation signal is given a predetermined characteristic based on the coefficient data FLT ₃ in the filter 17, is then multiplied by the amplitude control signal AMP ₃ in the multiplier 18, and is input to the resonance section 19. You. Accordingly, it signals input to the resonance unit 19 first, LOOP42 ₁ of H
After the low-frequency component is blocked by the PF 43 based on the coefficient HPF _n , it is input to one input terminal of the adder 44. The output signal of the adder 44 is an LPF 45, an APF
The signal is fed back to the other input terminal of the adder 44 via the DELAY 47 and the multiplier 48. Therefore, HPF43
Output signal of the adder 44 → LPF45 → APF46 →
As the circulation in the loop constituted by the DELAY 47 and the multiplier 48 is repeated, the phase difference between the frequency components changes and gradually attenuates. And APF46
The output signal of, after being treated in the same manner as LOOP42 ₁ in LOOP42 _2, is output from the resonance portion 19 as a musical tone signal OUTL and OUTR of L and R channels.

[0022] As described above, with a configuration in which the configuration of the resonance unit 19 LOOP42 ₁ and 42 ₂ are connected in cascade, since both set to the frequency f ₁ the basic frequency pitch of LOOP42 ₁ and 42 _2, resonance The frequency characteristic of the entire unit 19 is as shown by a curve a in FIG. 10, the curve b is a frequency characteristic in the case of LOOP42 ₁ or 42 ₂ alone, the frequency interval f _I are those recognized as the pitch to the human ear. As can be seen from this figure, LOOP having almost the same frequency characteristics
When cascaded 42 ₁ and 42 _2, because the frequency characteristics of the comb becomes steeper than that of LOOP42 ₁ or 42 ₂ alone, to synthesize a high tone of a certain quality of the pitch sensation it can.

Generally, a musical tone played by a natural musical instrument has a spectrum structure in which a noise-like component appears close to the original overtone, instead of a simple line spectrum, and has fluctuation. Then, in order to synthesize a musical tone similar to a natural musical instrument sound having such fluctuation in the musical tone synthesizing apparatus of the above-described embodiment, the control unit 8
For example, the amplitude control signals AMP ₁ and AMP ₂ may be set so that the ratio of the output signal of the filter 13 is larger than the output signal of the filter 12, contrary to the case described above.

[0024] Incidentally, as shown in FIG. 11, the left in LOOP42 ₁ of the fundamental frequency pitch of FIG. 9 the structure of the resonance portion 19 is set to a frequency f ₁ (see FIG. 12 curve a), and, L
OOP42 the _second fundamental frequency pitch set to a frequency 3f ₁ (see FIG. 12 curve b), the frequency characteristic of the whole resonance portion 19 is as shown in FIG. 13. Furthermore, with the configuration of the resonance unit 19 to the configuration shown in FIG. 14 (14 60 adders), it sets the basic frequency pitch of LOOP42 ₁ to frequency f _1, and the frequency of the fundamental frequency pitch of LOOP42 ₂ When f ₁ + Δf is set, the resonance section 19
The overall frequency characteristics are as shown in FIG. 15, and an effect by detuning (a function of slightly shifting the pitch) can be obtained.

As described above, since the resonance section 19 is constructed so that a plurality of LOOPs 42 _{1 to} 42 ₄ can be freely combined, a wide variety of timbres can be secured, and each of the LOOPs 42 _{1 to} 42 4 can be secured. _{Since 4} can be used within the stable operation range, the reliability as a system is high. Further, according to this embodiment, the harmonic structure of the generated musical tone is easier to predict than the sound source system using the modulation of the FM sound source and the like, and the calculation amount is smaller than the sound source system using the harmonic synthesis (Fourier synthesis system). Much less. further,
According to this embodiment, there is no particular need for high-quality musical sound data sampling or a large-capacity waveform memory, unlike a musical sound synthesizer using a sound source that reads out waveform data from a waveform memory.

[0026] In the embodiment described above, an example of only a combination of resonance portion 19 simply LOOP42 ₁ ~42 _4, for example, as shown in FIG. 16, L
Between OOP42 ₁ and LOOP42 _2, interstage processing circuit 6
1 may be inserted. In this case, for example, a non-linear table is provided to
Or nonlinear processing P42 ₁ output signal, or the amplitude control process of L OOP42 ₁ output signal by the compressor or limiter, etc., or reverberation, a variety of sound effects such as delay and chorus LOOP42 ₁ output signal Or to grant.

[0027]

Effect of the Invention] As described above, according to the present invention, although the tone by signal is sequentially input <br/> force to the loop means cascaded multiple stages are combined, the following Step loop means
Low frequency attenuation is performed by the low-frequency attenuation means with respect to signal before being input to. Thus, the inclusion of periodic component lap time over the length of the loop means to signal, it is possible to avoid diverging signal in a short period of time occurs stops the musical tone, the disadvantage that The effect is obtained.
Further, according to the present invention, the low-frequency attenuation means is used as the loop means.
Since they are not included, unnecessary low-frequency components are stored in the loop means.
Multiple loop means cascaded without stacking
Even in the case of a
Trouble (loop saturation, divergence) can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a musical sound synthesizer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a resonance unit 19.

FIG. 3 is a block diagram illustrating a configuration of a signal synthesis unit 21.

FIG. 4 is a block diagram showing a configuration of LOOP42.

FIG. 5 is a block diagram showing a configuration of a signal synthesis unit 49.

FIG. 6 is a block diagram illustrating an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

FIG. 7 is a block diagram illustrating an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

FIG. 8 is a block diagram illustrating an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

FIG. 9 is a block diagram illustrating an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

FIG. 10 is a diagram showing an example of the frequency characteristic of the block diagram shown in FIG. 9;

FIG. 11 is a block diagram showing an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

12 is a diagram showing an example of each of the frequency characteristics of LOOP42 ₁ and 42 ₂ shown in FIG. 11.

FIG. 13 is a diagram showing an example of the frequency characteristic of the block diagram shown in FIG. 11;

FIG. 14 is a block diagram illustrating an example of an algorithm of LOOPs 42 _{1 to} 42 ₄ .

FIG. 15 is a diagram showing an example of the frequency characteristic of the block diagram shown in FIG. 14;

FIG. 16 is a block diagram showing another configuration example of the resonance unit 19.

[Explanation of symbols]

6 ... performance operators, 7 ... tone parameter setting operators,
8 ... Control unit, 9 ... Excitation signal generation unit, 10 ... Waveform generation unit, 11 ... Noise generation unit, 12, 13, 17 ... Filter, 14, 15, 18, 22 to 37, 48, 50 ~
57: Multiplier, 16, 38 to 41, 44, 58 to 60
... Adder, 19, Resonator, 20 Resonant element controller, 21, 49, Signal synthesizer, 42, 42 ₁ to 4
_{2 4 ...... LOOP, 43 ...... HPF} , 45 ...... LPF,
46 ... APF, 47 ... DELAY, 61 ... Interstage processing circuit.

Claims (1)

(57) [Claims] 1. A cascade connection of a plurality of delay means each having delay means for setting a delay time corresponding to a pitch of a musical tone to be generated.
Number of loop means and interposed between the loop means and input to the next loop means
Musical tone synthesizing apparatus characterized by comprising a, and the low frequency attenuation means for attenuating the low-frequency component of that signal.