JP2004309811A - Timbre control method, waveform memory creating method, electronic musical sound generating method, timbre control system, waveform memory and electronic musical sound generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a timbre control method by which a source signal can be reproduced without adding any special circuit and attenuation of harmonics corresponding to percussion strength can be reproduced. <P>SOLUTION: The source signal is processed by a frequency characteristic time variation control means 3 so as to be a reverse characteristic of a time variation filter 6 varying a cutoff frequency when read-out waveform data are filtered with time, and stored in a waveform memory 4; when the stored signal is read out and filtered by the time variation filter 6, a filter envelope control means 7 controls time variation of the cutoff frequency of the time variation filter 6 according to percussion strength. Consequently, the source signal can be reproduced without adding any special circuit and attenuation of harmonics corresponding to the percussion strength can be reproduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a timbre control method for controlling a timbre by filtering a read-out waveform data by a digital filter, a method for creating a waveform memory used in the method, a method for generating an electronic musical tone by such timbre control, The present invention relates to a timbre control system, a waveform memory and an apparatus for generating an electronic musical tone by performing the method.
[0002]
[Prior art]
2. Description of the Related Art In an electronic musical instrument, it is common to read out waveform data stored in a waveform memory, apply a digital filter to the waveform data, and process the waveform data to change a timbre. I have.
For example, by storing one swipe waveform data for a certain pitch and controlling the cutoff frequency of the digital filter according to the keystroke strength, the overstrike includes less overtones and the overstrike includes more overtones. Can be generated.
[0003]
[Problems to be solved by the invention]
According to the above-described method, it is possible to obtain a change in timbre with respect to the keying strength. However, in an actual piano sound, the decay time of harmonics differs depending on the keystroke strength, and such a phenomenon cannot be reproduced.
[0004]
FIG. 12 shows the time change of the level of the 2nd overtone and the 7th overtone of the piano C3 at the time of the hard hit and the soft hit. According to this, the second harmonic is hardly changed between a strong hit and a weak hit, but the seventh harmonic has a faster decay than a strong hit. In this figure, the maximum level of each overtone is adjusted so that the attenuation can be easily compared. In fact, the level of the blow is small overall.
[0005]
In the above-described prior art, since the smashed waveform is stored in the waveform memory, even if the smashed waveform is filtered by a digital filter, the overtone decay remains smashed (the higher harmonics decay more quickly). Could not reproduce the difference.
[0006]
Further, it is conceivable to change the cutoff frequency of the digital filter with time. However, since the method using the digital filter is a subtraction method, it is necessary to store a strong strike waveform containing many overtones in the waveform memory. Since the decay of the level of the overtone of the heavy strike waveform is faster than that of the weak strike, the digital filter based on the subtraction method cannot slow down the fast decay.
[0007]
In order to solve this problem, a method has been devised in which a waveform memory stores not only strong hits but also waveforms of various hitting strengths such as middle hits and weak hits, and the readout waveform is switched according to the hitting strength. . This method can reproduce the difference in the attenuation of the overtones of the weak hit and the strong hit, but cannot change the tap strength continuously, and has a problem that the waveform memory increases.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in order to solve these problems. The present invention reproduces an original signal without adding a special circuit, and attenuates harmonics according to a keystroke strength. To provide a tone color control method, a waveform memory creation method, an electronic musical tone generating method, a tone color control system, a waveform memory, and an electronic musical tone generating device capable of reproducing the same.
[0009]
[Means for Solving the Problems]
Therefore, in the configuration of the tone color control method according to the present invention, when the read-out waveform data is filtered by changing the cutoff frequency over time, the original signal is processed in advance so that the filtering signal has the opposite characteristic to the filtering characteristic. When the above-mentioned filtering is performed by reading out the stored data from the waveform memory, the basic characteristic is that the temporal change of the filtering cutoff frequency is controlled by the keying strength.
[0010]
According to the above configuration, the original signal is processed in advance and stored in the waveform memory so that the digital filter used to generate a musical tone later has characteristics opposite to those of the digital filter. At the time, when the waveform data is read out and filtered by the digital filter, the time change of the cutoff frequency in the digital filter is controlled by the keying strength. Therefore, it is possible to reproduce the original signal while continuously changing the tapping strength without increasing the waveform memory and without adding a special circuit, and to reproduce the overtone attenuation according to the tapping strength. Become like The term "keying strength" includes a case where a filter is changed by inputting MIDI data.
[0011]
The waveform memory used for the configuration of such a tone control method is created as follows. That is,
For the waveform data stored in the waveform memory,
The original signal is pre-processed and stored in the waveform memory so that the read-out waveform data has a cut-off frequency that is changed with time and is filtered, so that the filtering signal has the reverse characteristic.
(Claim 2).
[0012]
A third aspect of the present invention specifies a method of generating an electronic musical tone whose tone is controlled by the above tone color controlling method (first aspect). That is, when the read-out waveform data is filtered by changing the cutoff frequency with time, the waveform signal is processed from the waveform memory in which the waveform data in which the original signal has been processed is stored so as to have the opposite characteristic to the filtering characteristic. An electronic musical tone generating method according to claim 3, characterized in that when said waveform data is read out and said filtering is performed, a temporal change of said filtering cutoff frequency is controlled by a keying strength. ing.
[0013]
On the other hand, the configuration of claim 4 defines a system configuration for implementing the tone color control method according to claim 1. That is,
A waveform memory for storing waveform data,
A frequency characteristic for processing an original signal and storing the same in the waveform memory so that the cut-off frequency of the waveform data read from the waveform memory is changed in time and has an inverse characteristic to the filtering characteristic when filtering is performed. Time-varying control means,
A digital filter that changes the cutoff frequency with time, which is used when reading and filtering the waveform data,
When performing the above-mentioned filtering by the digital filter, the digital filter has a filter control means for controlling a temporal change of a cutoff frequency in the digital filter depending on a keying strength.
[0014]
The waveform memory used for the configuration of such a tone color control system has the following configuration. That is, a data structure in which the original signal is processed and stored in advance so as to have a characteristic opposite to the filtering characteristic when filtering the read waveform data by changing the cutoff frequency with time is used. (Claim 5).
[0015]
Further, the configuration of claim 6 specifies an apparatus for generating an electronic musical tone whose tone is controlled by the above-described tone control system configuration (claim 4). That is,
A digital filter that changes the cutoff frequency over time when the read waveform data is filtered;
For the digital filter, a waveform memory in which the original signal is processed in advance so as to have the reverse characteristic and waveform data is stored,
When the waveform data is read and filtered by a digital filter, the apparatus has at least a filter control means for controlling a change over time of a cutoff frequency in the digital filter by a keystroke strength.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual diagram of the present invention.
[0017]
The waveform data creation unit 1 processes the original signal obtained by recording or the like and stores it in the waveform memory 4.
[0018]
The frequency characteristic time-varying control means 3 used for processing the original signal temporally changes the frequency characteristic of the musical tone signal so as to have the inverse characteristic of the filtering characteristic of the time-varying filter 6 described later. It has a function of storing the obtained waveform data in the waveform memory 4. The configuration includes a CPU (not shown) to a DSP (Digital Processing Unit; not shown) provided in an arbitrary computer, an electronic musical tone generator (including an electronic musical instrument), and the like; And a storage unit that stores a program for performing the following. Here, time-varying means time-varying. That is, the time-varying filter 6 is a digital filter that changes the cutoff frequency with time, and the time-varying control of the frequency-characteristic time-varying control means 3 is a control that changes the frequency characteristic over time. is there.
[0019]
Further, in the tone generator 2 shown in FIG. 1, the waveform data stored in the waveform memory 4 is read by the waveform data reading means 5 and filtered by the time-varying filter 6 to generate a tone.
[0020]
In this configuration, the filtering control of the time-varying filter 6 is performed by the filter envelope control means 7. The timbre information selected by the timbre selection means 151a constituted by a timbre selection switch 151 shown in FIG. 2 described later, and a pitch detection means 140a constituted by a keyboard section 140 shown in FIG. When the pitch-depressed information and the key-pressing strength information detected by the strength detecting means 141a are detected, the information is output to the filter envelope control means 7.
[0021]
The filter envelope control means 7 reads out the cutoff frequency and cutoff envelope data stored as a part of the timbre data in the timbre data memory 122 on the ROM 120 in FIG. From the information on the pitch and the keying strength, the frequency characteristic of the time-varying filter 6 given to the waveform data with respect to the passage of time is calculated (see FIGS. 3B and 3C described later). Control the envelope.
[0022]
The configuration of the filter envelope control means 7 includes a CPU 110 in FIG. 2 described below, a program memory 121 storing a program for causing the CPU 110 to perform the above-described processing, a cut-off frequency of the time-varying filter 6, The ROM 120 includes a tone data memory 122 in which tone data including a cutoff envelope as a part thereof is stored.
[0023]
The frequency characteristic time-varying control means 3 is the frequency characteristic time-varying control means of the present invention, the time-variant filter 6 is the digital filter of the present invention, and the filter envelope control means 7 is the filter control means of the present invention. Equivalent.
[0024]
FIG. 2 is an explanatory diagram showing a system configuration of an electronic musical instrument having the configuration of the musical tone generating section 2 of FIG.
[0025]
The system configuration of the electronic musical instrument includes a touch sensor connected to a system bus 100 via a CPU (Central Processing Unit) 110, a ROM (Read Only Memory) 120, a RAM (Random Access Memory) 130, and a keyboard scan circuit 142. 141 and the keyboard 140, the panel 150 connected via the panel scan circuit 152, the damper pedal 160 connected via the pedal scan circuit 161, the MIDI interface 170 for external input / output, and corresponding to each tone (tone parameter Waveform data reading which is stored in a waveform memory 4 for storing waveform data (designated as) and which reads out waveform data set in accordance with a timbre parameter (in accordance with a predetermined memory address). Output means 5 and a time-varying filter 6 for filtering the read-out waveform data to change the cutoff frequency with time are connected to each other. Delivery is made. On the output side of the time-varying filter 6, a D / A conversion circuit 180 for converting a musical tone subjected to a filtering process into an analog signal, an amplifier for amplifying the digital signal, and a sound system 181 such as a speaker for generating an external sound are electrically connected. Connected.
[0026]
The CPU 110 controls each part of the electronic musical instrument according to the present embodiment according to a control program stored in a program memory 121 described later on the ROM 120, and also controls the electronic musical tone generation method stored in the program memory 121. Is executed, the RAM 130 is used as a work area as needed, and data processing is performed using various fixed data stored in the ROM 120.
[0027]
The ROM 120 stores a program memory 121 in which a control program for the electronic musical instrument and an application program for an electronic musical tone generation method according to the present invention are stored, and a tone color selection switch 151 of a panel 150 described later. At least a timbre data memory 122 in which information of a timbre cutoff frequency and a cutoff envelope is stored together as a part of timbre data, and other various fixed data used by the CPU 110 are stored.
[0028]
The RAM 130 stores status information of the electronic musical instrument and is used as a work area of the CPU 110. Various registers, flags, and the like for controlling the electronic musical instrument are defined in the RAM 130, and the RAM 130 is accessed by the CPU 110 via the system bus 100.
[0029]
The keyboard section 140 is composed of the keyboard of the present electronic musical instrument, and includes a plurality of keyboards and a keyboard switch that opens and closes in conjunction with the depression and release of the keys, and detects the pitch of the depression of the keys ( This corresponds to the pitch detecting means 140a in FIG. 1). In addition, these keys are provided with a touch sensor 141 for detecting a key-pressing speed at the time of key-pressing consisting of a two-point switch set in a key moving direction at the time of key-pressing. A keyboard scan circuit 142 interposed between the keyboard unit 140 and the touch sensor 141 and the system bus 100 checks the state of the keyboard switch, and outputs ON / OFF information and the keyboard number from a signal indicating ON / OFF. At the same time, it generates keystroke strength data [touch data indicating the strength (speed) of keyboard touch] from the detection signal of the touch sensor 141. The ON / OFF information, the keyboard number, and the touch data are sent to the CPU 110 via the system bus 100 as key press information.
[0030]
The panel 150 includes a tone selection switch 151 (corresponding to the tone selection means 151a in FIG. 1), various switches such as a power switch, switches for mode selection, and the like, and a volume changer. ing. The panel scan circuit 152 interposed between the panel 150 and the system bus 100 checks the set / reset state of each switch or touch panel provided on the panel 150 and detects panel switch data that is in the ON state. To the CPU 110.
[0031]
The waveform data reading means 5 is configured to read out (read from the address) waveform data stored in the waveform memory 4 in accordance with a read address specified by the CPU 110. A sound source LSI shown in FIGS. 8 and 10 to be described later is constituted by a configuration including the waveform data reading means 5 and the time-varying filter 6.
[0032]
In the present embodiment, since the configurations of the waveform memory 4 and the time-varying filter 6 shown in FIG. 1 have been described in the description of FIG. 1, detailed description thereof will be omitted. However, in the present embodiment, the filter envelope control means 7 not shown in FIG. 2 stores the CPU 110 and a program for causing the CPU 110 to perform processing of the time-varying filter 6 as described above. And a ROM 120 having a built-in timbre data memory 122 in which timbre data including a cutoff frequency and a cutoff envelope of the time-varying filter 6 as a part thereof are stored. Here, the processing in the time-varying filter 6 refers to reading out the cutoff frequency and cutoff envelope data stored as a part of the timbre data in the timbre data memory 122, the pitch input from the keyboard scan circuit 142, and the keystroke. From the information on the strength, a frequency characteristic of the time-varying filter 6 to be given to the waveform data with respect to the passage of time is calculated (see also FIGS. 3B and 3C described later), and the filter envelope of the time-varying filter 6 is controlled. Processing.
[0033]
It should be noted that the above configuration further includes a sampling configuration (not shown) that configures the waveform data creation unit 1 of FIG. 1 that fetches an original signal, processes the original signal, and stores the processed signal in the waveform memory 4. It can also be provided as a synthesizer or the like to be configured. In that case, the configuration of the frequency characteristic time-varying control means 3 for processing the original signal is constituted by the CPU 110 in FIG. 2 and a program memory 121 in which a program for causing the CPU 110 to perform such processing is stored. become.
[0034]
A method for synthesizing a musical tone according to the present invention will be described with reference to FIGS. FIG. 3A shows the frequency processing characteristics of the frequency time varying control means 3 added to the original signal. FIG. 4A shows the frequency characteristics of the waveform data stored in the waveform memory 4 after the processing. FIGS. 3B and 3C show the characteristics of the time-varying filter 6 added (filtered) to the read waveform data at the time of a strong hit and at the time of a light hit, and FIG. FIG. 4B and FIG. 4C show the output frequency characteristics of the waveform data when hitting hard and when hitting weakly.
[0035]
First, the waveform data to be stored in the waveform memory 4 is created in the waveform data creation unit 1 of FIG.
[0036]
As described above, since the method using a filter is a subtraction method, a recording of a strong tapping sound including many overtones is used as an original signal. As shown in the processing characteristics of the waveform data in FIG. 3A, processing is performed on the tone signal of the strong tapping sound [see FIG. 4B] so that the level in the high frequency band increases over time (normally). The level characteristic of the high-frequency band over time is opposite to the waveform data at the time of the hit.) This characteristic is obtained from the difference in the time change of the frequency characteristics of the heavy hitting sound and the low hitting sound, and is set so that the time change of the strong hitting sound becomes a weak hitting sound (see the description of FIG. 12 above). .
[0037]
As a result, as shown in FIG. 4A, the temporal change of the level of the lower harmonic stored in the waveform memory 4 is almost the same as that of the original signal [the level on the far side in FIG. Almost no change], but the higher harmonics are processed so that the level (which should be attenuated) becomes larger than the original signal over time and stored in the waveform memory 4 as shown in FIG. Therefore, when a filter having a filter characteristic at the time of a weak hit as shown in FIG. 3C is applied, the attenuation of the original signal becomes slow, and as a result, the weak hit occurs as shown in FIG. Waveform data equivalent to the attenuation of the higher order harmonics is created.
[0038]
In the waveform data creation unit 1, the waveform data (see FIG. 4A) on which the above-described processing has been performed by the frequency characteristic time-varying control unit 3 is stored in the waveform memory 4.
[0039]
Next, a description will be given of a configuration in which the waveform data processed as described above is read out from the waveform memory 4 and the musical sound generating section 2 generates a musical sound.
[0040]
First, at the time of a blow, the characteristics of the time-varying filter 6 are controlled by the filter envelope control means 7 to have the characteristics shown in FIG. 3B, and the waveform data [ FIG. 4 (a)] provides such a filtering characteristic. This characteristic is opposite to the processing characteristic at the time of generating the waveform data in FIG. 3A. Therefore, the processing characteristics of the waveform data (stored in the waveform memory 4) and the characteristics of the time-varying filter 6 to be applied cancel each other out, and the original signal, that is, the strong tapping sound as shown in FIG. (Higher harmonics decay faster when hit hard).
[0041]
On the other hand, at the time of a light hit, the characteristics of the time-varying filter 6 are controlled by the filter envelope control means 7 to have the characteristics shown in FIG. FIG. 4 (a)] provides such a filtering characteristic. This characteristic is such that the level of the high frequency band can be lowered, and does not change with the passage of time (the characteristic is such that the level of the high frequency band can be uniformly lowered without a change over time). ing). Therefore, the level of the higher harmonics is uniformly smaller than that of the waveform data, and the time change of the higher harmonics is as shown in the processed waveform data. Since the difference from the attenuation is reduced), as shown in FIG. 4C, a low-pitched sound that reproduces not only the level of each harmonic but also the attenuation of the higher-order harmonic is synthesized.
[0042]
Further, depending on the tone selected by the tone selection switch 151 and the depressed pitch detected by the keyboard section 140, respective parameters are read from the tone data memory 122 and given to the filter envelope control means 7. The envelope of the time-varying filter 6 is changed by the filter envelope control means 7.
Basically, these are processed by the waveform data creation unit 1 in accordance with the above-mentioned tone color and pitch, so that characteristics are obtained in accordance therewith.
[0043]
Now that the tone synthesis method according to the present invention has been clarified, a method of creating waveform data stored in the waveform memory 4 by the frequency characteristic time-varying control means 3 in the waveform data creation unit 1 will be described.
[0044]
As described above, in order to change the frequency characteristics of the original signal with the passage of time with the characteristics of FIG. 3A, the level of each bank with respect to the passage of time may be changed using a filter bank. FIG. 5 shows an example of the filter bank. This filter bank divides the audible band into a plurality of frequency bands, and obtains a signal of each band with respect to the original signal.
In accordance with these bands, the level of the signal in each band with respect to the passage of time is changed.
[0045]
FIG. 6 shows a change in level over time in each band. This characteristic is obtained by calculating the characteristic of FIG. 3A in the time direction for each frequency band. In the low frequency band (the back side of the drawing), the level does not change with the passage of time, but in the high frequency band, the level is set so that the higher the frequency (the closer to the front side of the drawing), the larger the level with the passage of time. You.
[0046]
FIG. 7 shows a part of the band of FIG. 6 extracted and displayed. At 1 kHz, there is almost no change over time, but at 2 kHz, the level gradually increases, and as the frequency increases to 3 kHz, 4 kHz, the level change also increases.
[0047]
In this way, all the signals of the respective bands whose levels have been changed by the frequency characteristic time-varying control means 3 are added, and the sum is stored in the waveform memory 4 as waveform data.
[0048]
Next, a flowchart of a main routine of the system configuration of the electronic musical instrument (musical tone generation unit 2) according to the present embodiment will be described.
[0049]
FIG. 8 shows a flowchart of a main routine of the electronic musical instrument constituting the musical tone generating section 2. First, when the power is turned on, the CPU 110, the RAM 130, the scan circuits 142, 152, and 161 and the sound source LSI including the waveform data reading means 5 and the time-varying filter 6 are initialized (step S101). Thereafter, the panel event process (Step S102), the pedal event process (Step S103), the keyboard event process (Step S104), and other processes (Step S105) are repeated. The panel event processing and the keyboard event processing will be described later.
[0050]
FIG. 9 is a flowchart of the panel event process shown in step S102 of FIG.
[0051]
Here, first, it is determined whether or not the tone color selection switch 151 (tone color selection means 151a) is pressed (step S201). If the button has been pressed (step S201; Y), a tone color selection process is performed (step S202). Here, the flag indicating the selected timbre is turned on, and the LED of the switch of the selected timbre is turned on. Thereafter, information of the selected timbre is set in the filter envelope control means 7 (step S203). Then, the process returns to the main routine of FIG.
[0052]
If the tone color selection switch 151 has not been pressed (step S201; N), it is determined whether another switch has been pressed (step S204). If the button has been pressed (step S204; Y), other processing is performed (step S205). Then, the process returns to the main routine of FIG.
[0053]
If no other switch has been pressed (step S204; N), the process returns to the main routine without doing anything.
[0054]
FIG. 10 shows a flowchart of the keyboard event process in step S104 of FIG.
[0055]
Here, first, the keyboard scan circuit 142 determines whether an ON event, that is, whether the keyboard section 140 is depressed (step S301). In the case of an ON event (step S301; Y), the touching strength is detected by the touch sensor 141 (keying strength detecting means 141a) (step S302). Subsequently, the pitch is detected by the pitch detecting means 140a (step S303). These pieces of information are input to the filter envelope control means 7.
[0056]
Next, the timbre data is read from the timbre data memory 122 of the ROM 120 (step S304). Then, the filter envelope is calculated by the CPU 110 constituting the filter envelope control means 7 (step S305). At this time, as shown in FIG. 11, the envelope speed of the filter is set to increase as the keystroke strength increases. By applying the speed data obtained here to the cut-off frequency of the time-varying filter 6 under the control of the filter envelope control means 7, the characteristic that the higher the keying strength is, the higher the frequency band is attenuated. Will be.
[0057]
Subsequently, other data is calculated (step S306). Thereafter, the calculated data is loaded into the waveform data reading means 5 and the time-varying filter 6 constituting the sound source LSI, and a tone generation process is performed (step S307). Then, the process returns to the main routine of FIG.
[0058]
On the other hand, if the event is not the on event in step S301 (step S301; N), then the keyboard scan circuit 142 determines whether the event is the off event (step S308). In the case of an off event (step S308; Y), the pedal scan circuit 161 further determines whether the damper pedal 160 is on (step S309). If the damper pedal 160 is on (step S309; Y), the process returns to the main routine. If the damper pedal 160 is off (step S309; N), the release speed is loaded into the waveform data reading means 5 and the time-varying filter 6 to perform a silencing process (step S310). Then, the process returns to the main routine of FIG.
[0059]
If the event is not an off event in step S308 (step S308; N), the process returns to the main routine without performing anything.
[0060]
According to the configuration according to the present embodiment described above, the above-described waveform data generation is performed with respect to the configuration of the musical sound generation unit 2 that forms the electronic musical instrument that controls the tone by applying the filtering by the time-varying filter 6 to the read waveform data. In the section 1, the frequency characteristic time-varying control means 3 pre-processes the original signal so as to have the inverse characteristic to the filter characteristic of the time-varying time-varying filter 6 added to the read waveform data. The waveform data is stored in the waveform memory 4. In the musical tone generator 2 constituting the electronic musical instrument, the processed waveform data is read out from the waveform memory 4, and when the filtering by the time-varying filter 6 is applied, the key is inputted by the filter envelope control means 7. According to the strength, the cut-off frequency in the time-varying filter 6 is time-controlled.
[0061]
In this case, the processing characteristics of the waveform data stored in the waveform memory 4 in the waveform data creating section 1 are different from those of the high-pitched tone signal as shown in FIG. Since the level is processed so as to increase, the temporal change of the level of the lower harmonic is not different from that of the original signal, but the higher harmonic is processed so that the level increases as time elapses as described above. When a filter having a filter characteristic at the time of a light hit is applied as shown in FIG. 3 (c), the attenuation of the original signal is delayed, and as a result, the attenuation is equal to that of the higher harmonic of the light hit. Waveform data is created. Therefore, in the tone generator 2, the processed waveform data is read out from the waveform memory 4 and a tone is generated. The characteristics of the time-varying filter 6 are controlled to have the characteristics shown in FIG. 3B [the characteristics are the inverse of the processing characteristics at the time of generating the waveform data in FIG. Since such filtering characteristics are added to the waveform data read out from the device, the processing characteristics of the waveform data and the characteristics of the time-varying filter 6 to be applied are canceled out, and the original signal, that is, the strong tapping sound is synthesized. (Higher harmonics decay faster when hit hard). On the other hand, at the time of a light hit, the filter envelope control means 7 similarly reduces the characteristic as shown in FIG. ), The characteristics of the time-varying filter 6 are controlled, and such filtering characteristics are given to the waveform data read from the waveform memory 4. Therefore, the level of the higher harmonics is uniformly smaller than the waveform data, and the temporal change of the higher harmonics is as shown in the processed waveform data. The difference between the overtone decay and the overtone decay is reduced), and a low-pitched sound that reproduces not only the level of each overtone but also the decay of the higher-order overtone is synthesized.
[0062]
With such a configuration, the original signal is reproduced while continuously changing the keying strength without increasing the waveform memory 4 and without adding a special circuit, and harmonics corresponding to the keying strength are reproduced. Can be reproduced.
[0063]
Note that the electronic musical instrument (electronic musical sound generating device) is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the scope of the present invention. For example, in the present embodiment, the original signal is processed by using the filter bank in the waveform data creating unit 1, but another method may be used. For example, the frequency characteristic may be changed by changing the coefficient of the time-varying filter 6 over time.
[0064]
【The invention's effect】
As described above, according to the timbre control method and the timbre control system according to the first and fourth aspects of the present invention, the digital filter used to generate a musical tone has a characteristic opposite to that of the digital filter. The original signal is processed in advance and stored in a waveform memory, and when a musical tone is generated, the waveform data is read out and filtered by the digital filter. Since the time change of the frequency is controlled, the characteristics of the digital filter are controlled at the time of a blow, which is the inverse of the processing characteristics at the time of creating the waveform data, and the waveform data read from the waveform memory is added to the waveform. Such filtering characteristics are imparted, and the processing characteristics of the waveform data and the characteristics of the digital filter to be imparted cancel each other out. The original signal of the digital filter is synthesized, and at the time of a light strike, the level of the high frequency band is reduced, and the characteristic of the digital filter is controlled so that it does not change over time. Since such a filtering characteristic is added to the output waveform data, the level of the higher-order harmonics is uniformly smaller than the waveform data, and the time change of the higher-order harmonics is the same as the processed waveform data. In other words, the difference between the attenuation of the higher harmonics and the attenuation of the lower harmonics is reduced, and a low-pitched sound that reproduces not only the level of each harmonic but also the attenuation of the higher harmonics is synthesized.
[0065]
Therefore, it is necessary to reproduce the original signal while continuously changing the tapping strength without increasing the waveform memory and without adding a special circuit, and to reproduce the overtone attenuation according to the tapping strength. Can be done.
[0066]
According to the waveform memory creating method and the configuration of the waveform memory according to the second and fifth aspects, the timbre control method or the timbre control system according to the first to fourth aspects and the third to third aspects. A memory having waveform data that can be used in the electronic musical tone generating method or electronic musical tone generating device described in Item 6 can be provided.
[0067]
Further, according to the electronic musical tone generating method and the electronic musical tone generating device according to the third and sixth aspects, similarly to the above, the keystroke strength can be reduced without increasing the waveform memory and without adding a special circuit. In addition to reproducing the original signal while continuously changing the frequency, it is possible to reproduce the attenuation of harmonics according to the keystroke strength.
[Brief description of the drawings]
FIG. 1 is a conceptual explanatory diagram of the present invention.
FIG. 2 is an explanatory diagram showing a system configuration of an electronic musical instrument having a configuration of a musical tone generating unit 2.
FIG. 3 is an explanatory diagram of a method of synthesizing a musical tone according to the present invention.
FIG. 4 is an explanatory diagram showing waveform data characteristics stored in a waveform memory and frequency characteristics of a synthesized sound output at the time of strong hit and light hit by the time-varying filter processing according to the present invention.
FIG. 5 is an explanatory diagram showing an example in which the level of each bank with respect to the passage of time is changed using a filter bank, and the frequency characteristic of the original signal is changed with the passage of time with the characteristics shown in FIG. .
FIG. 6 is an explanatory diagram showing a change in level with respect to the passage of time in each band.
FIG. 7 is a graph in which a part of the band in FIG. 6 is extracted and displayed.
FIG. 8 is a flowchart of a main routine of the electronic musical instrument constituting the musical sound generator 2.
FIG. 9 is a flowchart of a panel event process shown in step S102 of FIG.
FIG. 10 is a flowchart of a keyboard event process in step S104 of FIG. 8;
FIG. 11 is an explanatory diagram showing the state of the filter envelope calculated by the CPU 110 constituting the filter envelope control means 7;
FIG. 12 is a graph showing the time change of the level of the 2nd overtone and the 7th overtone of the piano C3 during the hard hit and the soft hit.
[Explanation of symbols]
1 Waveform data creation section
2 Tone generator
3 Frequency characteristic time-varying control means
4 Waveform memory
5 Waveform data reading means
6 Time-varying filter
7 Filter envelope control means
100 system bus
110 CPU
120 ROM
121 program memory
122 Tone Data Memory
130 RAM
140 keyboard
140a pitch detecting means
141 Touch sensor
141a Keying strength detection means
142 Keyboard Scan Circuit
150 panels
151 Tone selection switch
151a Tone selection means
152 Panel Scan Circuit
160 damper pedal
161 Pedal scan circuit
170 MIDI interface
180 D / A conversion circuit
181 sound system

Claims (6)

The original signal is processed in advance and stored in a waveform memory so as to have a characteristic opposite to the filtering characteristic when filtering the read-out waveform data by changing the cutoff frequency with time, and reading out this. Wherein the time change of the filtering cutoff frequency is controlled by the keystroke strength when performing the above filtering. For the waveform data stored in the waveform memory,
When the read-out waveform data is filtered by changing the cutoff frequency with time, the original signal is processed in advance and stored in the waveform memory so as to have a characteristic opposite to the filtering characteristic. How to create a waveform memory. When the read-out waveform data is subjected to time-varying cut-off frequency filtering, the waveform data stored in advance from the waveform memory in which the original signal has been processed so as to have the inverse characteristic to the filtering characteristic is obtained. An electronic musical tone generating method, wherein, when the waveform data is read out and the above-mentioned filtering is performed, a temporal change of the filtering cutoff frequency is controlled by a keying strength. A waveform memory for storing waveform data,
A frequency characteristic for processing an original signal and storing the same in the waveform memory so that the cut-off frequency of the waveform data read from the waveform memory is changed in time and has an inverse characteristic to the filtering characteristic when filtering is performed. Time-varying control means,
A digital filter that changes the cutoff frequency with time, which is used when reading and filtering the waveform data,
A tone control system for controlling the temporal change of a cutoff frequency in the digital filter according to a keystroke strength when performing the filtering with the digital filter. It has a waveform data structure in which an original signal is processed and stored in advance so as to have a characteristic opposite to the filtering characteristic when filtering the read waveform data by changing the cutoff frequency with time. A waveform memory. A digital filter that changes the cutoff frequency over time when the read waveform data is filtered;
For the digital filter, a waveform memory in which the original signal is processed in advance so as to have the reverse characteristic and waveform data is stored,
An electronic musical tone generating apparatus comprising: at least filter control means for controlling a time change of a cutoff frequency in the digital filter according to a keying strength when the waveform data is read and filtered by a digital filter. .

Images