JPH08137470A - Frequency characteristic controller for musical tone signal - Google Patents

Abstract

PURPOSE: To make generated musical tones distinct and to produce natural musical tones by variously controlling the filter characteristics according to an increase or decrease in the number of the tones to be simultaneously produced. CONSTITUTION: The channel number ONn of subjected to note-on is counted and a cumulative value TEL of the coefft. EL meeting the compass of the keys subjected to note-on is determined. A filter determination level AL meeting the note-on count value ONn is corrected by a correction constant DK determined according to the on/off of the coefft. EL and a damper pedal. Filter coeffts. a1 to an are determined according to the high and low of the filter characteristic determination level AL after the correction. These filter coeffts. a to an are supplied to the digital filter 18, by which the filter characteristics are so set as to be made adequate according to a change in the number of the tones to be simultaneously produced. Filtering of the synthesized musical ton signal SD outputted from an accumulator 17 is executed by the set filtering characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone signal frequency characteristic control device for controlling the frequency characteristic of a musical tone signal in accordance with the number of musical tones produced simultaneously.

[0002]

2. Description of the Related Art Electronic musical instruments using digital sound sources in recent years are
Some are capable of producing multiple tones at the same time. This is to generate musical tone signals generated by using digital data one by one in a multi-channel time division method, accumulate and synthesize these digital musical tone signals, and convert them into analog signals with a DA converter. It is pronounced from the sound system.

[0003]

However, in an electronic musical instrument equipped with the above digital tone generator system, for example, an electronic piano, when playing a song having a large number of simultaneous sounds,
The musical sounds are mixed and the clarity of the musical sounds is lowered. As one of means for solving this, it is considered that the attenuation speed of each musical sound is uniformly increased so that each musical sound is attenuated quickly after being sounded. However, if the decay time of each tone is shortened uniformly in this way, it is good when there are many polyphonies, but when playing a quiet song with few polyphonies, there are many periods in which only single notes are pronounced. Moreover, this single tone is attenuated quickly, resulting in an unnatural tone. Further, it is considered that the unclearness when the number of polyphony is large is due to the fact that a large number of sounds in a specific frequency band included in each musical sound are mixed.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to eliminate the ambiguity of musical tones when the number of polyphonic sounds is large, and to solve the problem when the number of polyphonic sounds is small. This is to prevent unnatural attenuation of musical sounds and to produce clear and natural musical sounds.

[0005]

In order to solve the above-mentioned problems, the present invention, as shown in FIG.
1, a tone signal generation means M2, a filter means M3,
The determinant detecting means M4 and the filter controlling means M5 are provided.

The tone signal generating means M2 generates and outputs a plurality of tone signals according to the respective instructions of the plurality of tone instructing means M1. The determinant for determining the filter characteristic of the filter means M3 is detected by the determinant detecting means M4. Based on this determinant, the filter control means M5 appropriately filters the tone signal in the specific frequency band that causes obscuring the tones to be produced, when the number of simultaneous tones increases. The characteristics are variably set. Further, when the number of polyphonic sounds decreases, the filter characteristic of the filter means is variably set so that a natural musical tone with no discomfort can be obtained.

[0007]

As a result, the filter characteristic of the filter means is set so as to obtain an appropriate filter characteristic according to the increase / decrease in the number of polyphonic sounds, and the frequency characteristic of the synthesized tone signal is properly controlled. Therefore, when the polyphony number is large, the filter characteristic is set so as to have the attenuation characteristic according to the polyphony number. As a result, the frequency components in the specific band that obscure the musical tone to be pronounced are attenuated, and the musical tone to be pronounced becomes clear. In addition, when the number of polyphony is small, the attenuation of the frequency component of the specific band is low, or the filter characteristic is set so that the frequency component of the specific band is not attenuated. Can be pronounced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments described below are examples in which the present invention is applied to an electronic musical instrument which is produced by simulating sounds generated by an acoustic piano and other musical instruments by a digital sound source.

1. Overall Circuit FIG. 2 shows the overall circuit of the electronic musical instrument. Each key of the keyboard 1 is used to perform sound production / silence operation. The key scan circuit 2 scans the keyboard 1 and sends data representing key-on and key-off to the CPU 5. The key-on and key-off scan data are stored in the RAM by the CPU 5.
Written in 6. Then, the CPU 5 discriminates an on event and an off event of each key stored in the RAM 6 up to that point. The key scan circuit 2 detects a touch at the time of key-on or key-off and sends the touch data to the CPU 5. The keyboard 1 can be replaced with a string instrument (such as a violin), a wind instrument (such as a flute), a percussion instrument (such as a cymbal), or a computer keyboard.

The panel switch group 3 includes a power switch,
Various switches such as a mode designation switch, a melody selection switch, a rhythm selection switch, and a tone color selection switch (not shown) are provided. The set / reset state of these switches is detected by the panel scan circuit 4,
This scan data is sent to the CPU 5 and written in the RAM 6. Then, by the CPU 5, RA until then
The data indicating the set / reset state of each switch stored in M6 is compared to determine the on-event / off-event of each switch.

The RAM 6 stores various data processed by the CPU 5 and various data necessary for the processing. ROM
7 stores a program executed by the CPU 5 according to a flowchart described later and a program corresponding to other processing. 5 and 6 are executed by the CPU 5, and the process of FIG. 7 is executed by the CP in the tone generator 11.
It may be executed by U (not shown).

A tone generator (also called DCO) 11 as a digital sound source generates digital tone signals for a plurality of channels by time division processing. The frequency number accumulator 12 instructs the musical tone waveform memory 13 to read out the musical tone waveform data MW for which a tone generation instruction has been issued. To the frequency number accumulator 12, the CPU 5 sends the key number data KN and the tone number data TN,
Frequency number data FN corresponding to key number data KN
Are accumulated in time division, and the accumulated accumulated frequency number data FNA is supplied to the tone waveform memory 13 as read address data in time division. Tone number data T
N is sent to the frequency number accumulator 12 by the CPU 5, converted into bank data BK, and supplied to the tone waveform memory 13 as upper read address data. The lower read address data is the accumulated frequency number data FNA.

The tone waveform memory 13 stores a plurality of tone waveform data MW. Each tone waveform data MW
The selection of each tone waveform data MW to be read out in time division based on the accumulated frequency number data FNA is performed based on the tone number data TN. The musical tone waveform data MW is sampling data of waveforms of a plurality of types of musical instrument sounds such as piano, violin, flute and marimba.

The envelope generator 14 is a CPU
It also has a DSP and determines the envelope of the musical sound that is produced. This envelope generator 14 has a C
The tone number data TN is sent by PU5,
An envelope level EN corresponding to the tone number data TN is generated in a time division manner.

The tone waveform data MW from the tone waveform memory 13 and the envelope level data EN are multiplied by the multiplier 1.
6 is multiplied, and the accumulator 17 accumulates the musical tone data of all channels. The synthesized tone signal output from the accumulator 17 is filtered by the digital filter 18, converted into an analog signal by the DA converter 19, and then converted into audible sound by the sound system 20.

The digital filter 18 is composed of a hardware arithmetic circuit, and is a non-recursive (FIR) or recursive (IIR) digital filter. The digital filter 18 filters the synthetic tone signal SD by performing a convolution calculation or the like. The filter coefficients a1 to an used for this filtering calculation are stored in the coefficient memory 21. The coefficient memory 21 is a rewritable memory, and the coefficient memory 21 is rewritten by the CPU 5. Filter coefficients a1 to an
Is a factor that determines the filter characteristic of the digital filter 18, so that the filter characteristic of the digital filter 18 can be controlled by variably setting the filter coefficients a1 to an.

The pedal 10 may be a damper pedal, a soft pedal, a sostenuto pedal, etc. (none of which are shown).
Operation information of the pedal 10 is detected by the pedal sensor 9, and this operation data is sent to the CPU 5 and written in the RAM 6.

As shown in FIG. 3, the assignment memory 8 has a plurality of channels CH1 to CHn (for example, 16 channels).
The memory area of the channel) is formed.
In these memory areas, key number data KN, key on / key off data, tone number data TN (tone data), touch data, envelope level EN /
Data related to musical tones such as phase data FZ is stored for each channel.

The key-on / key-off data indicates whether the musical sound to which the channel is assigned is key-on or sounding, key-off or muting. The envelope phase data FZ indicates attack, decay, and release of the envelope of the sounded tone. The assignment memory 8 may be provided in the tone generator 11.

2. Register Group FIG. 4 shows the register group of the RAM 6 and the envelope memory 1.
5 shows a data table of No. 5. A damper pedal on flag DF is stored in the register 30. The register 31 stores a correction constant DK for correcting the filter characteristic determination level AL according to the operation of the damper pedal. The correction constant DK is a predetermined value, is determined according to a determinant factor according to the operation of the damper pedal, and is set in step 100 described later. In the register 32,
Note-on count value O that indicates the number of key presses (note-on)
Nn is stored. Register 33 is for each channel CH
The range distribution coefficient EL, which is determined according to the range of the musical tones produced by 1 to CHn, is temporarily stored. The register 34 stores an accumulated distribution coefficient TEL obtained by accumulating the range distribution coefficient EL. The synthetic tone signal data S is stored in the register 35.
A filter characteristic determination level AL for determining to which of the filter circuits F1 to F4 D is supplied is stored.
The register 36 stores channel number data n used in a note-on count process and the like which will be described later. The filter coefficient data a1 to an written in the coefficient memory 21 are temporarily stored in the registers 37-1 to 37-n.

The data table 40 stores target level data TL and speed data SP for each phase of attack, decay and release, and for each musical factor. The target level data TL is the reaching level of the envelope level set for each phase, and the speed data is data that determines the speed at which the envelope level reaches the target level.

The musical factors are pitch, range, kind of tone, touch amount, effect (reverb, echo,
Glide, portamento) type and / or size, sound image position, rhythm type, performance part (melody,
Chord, bass, background, rhythm) type,
Modulation amount, envelope level, envelope speed,
It includes the elapsed pronunciation time, the volume, the number of pronunciations, the quantize amount, the size of tempo, the filter characteristic data, and the like.

3. Overall Process FIG. 5 is a flowchart of the overall process executed by the CPU 5. This process starts when the power is turned on, and the CPU 5, the RAM 6, the assignment memory 8, the tone generator 11, etc. are initialized (step 100). Then, panel event processing (step 20)
0), pedal event processing (step 300), musical tone generation processing (step 400), and filter control processing (step 600) are repeatedly executed.

Other processes SJ include key-on event process and key-off event process, channel assignment process, effect process such as reverberation sound generation process and resonance sound generation process according to operation of the pedal 10, automatic performance process, MIDI data transmission / reception. This is processing of additional functions such as processing. An example of the reverberation sound generation process is disclosed in Japanese Patent Application No. 6-38608, and an example of the resonance sound generation process is described in Japanese Patent Application No. 5-1.
There is one disclosed in 37863.

When the tone of the key for which there is a key-on event is sounded, its envelope is attacked, decayed,
Although the sound is changed in the order of release to be muted, the reverberation sound and the resonance sound of the musical sound of the key having the key-on event are generated by the reverberation sound generation processing and the resonance sound generation processing. Therefore,
The number of simultaneous sounds is increased by the generation processing of the musical tone of the key having the key-on event and the generation processing of the reverberation sound and the resonance sound. In addition, since reverberation is often generated even after a key-off event, the number of simultaneous sound generations may be greater than the number of key presses even if the number of key presses decreases due to key-off.
The key-on event and the key-off event are based on not only the operation of the keyboard 1 but also the reproduced automatic performance data and the data from other devices sent from the MIDI system.

4. Pedal Event Processing FIG. 6 is a flowchart of the pedal event processing (step 300). Steps 302 to 310 are damper pedal processing for storing the on / off state of the damper pedal. Based on the operation data of the pedal 10 sent from the CPU 5 and the pedal sensor 9, the on / off event of the damper pedal is determined (steps 302, 30).
6). Damper pedal on flag DF at on event
Is set (step 304), and the damper pedal on flag DF is reset at the off event (step 3).
08). The damper pedal on flag D is a flag for storing the on / off state of the damper pedal, and is stored in the RAM 6. In the off-event, the mute processing of the musical sound extended while the damper pedal is depressed is performed (step 310). In this mute processing, the sound generation is stopped by clearing the key-off channel in the assignment memory 8 that is sounding.

In the other pedal processing (step 312), for example, a flag is set / reset according to an on event / off event of a soft pedal or a sostenuto pedal, or the volume of a musical sound to be generated according to the amount of pedal depression is changed. The value of the parameter to be changed is determined.

5. Musical Sound Generation Process FIG. 7 is a flowchart of the musical sound generation process (step 400) executed by the CPU 5. In this process, musical tone signals of a plurality of channels are generated sequentially or in a time division manner. Therefore, the channels are switched at an indefinite cycle or a constant cycle, and the following processing is repeatedly executed for each channel.

The musical tones produced by the sound system 20 are polyphonic, and a plurality of musical tones are produced at the same time when the assignment memory 8 has a plurality of channels storing key-on or data being produced. The CPU 5 and the tone generator 11 execute the tone generation processing (step 400) for each channel CH1 to CHn one by one in an indefinite or constant cycle (steps 402, 432, 434). As a result, the musical tone waveform MW is formed in time division for the musical tone to which the key-on or sounding channel is assigned,
It is serially output to the accumulator 17. Multiple channels of musical tone waveform data MW serially input by the accumulator 17.
Are accumulated to form synthetic tone signal data SD.
The synthetic tone signal data SD is sent to the digital filter 18 at a predetermined timing.

First, the CPU 5 increments the channel number data n of the register 39 by "1" (step 402). Next, based on the stored contents of the assignment memory 8, it is determined whether the key of channel 1 assigned in the time division process is an on event or an off event (steps 404 and 410). This is based on the key-on event flag or the key-off event flag detected in the key-on event process and the key-off event process in the above-mentioned other process SJ. If it is a key-on event, sound generation is started from this key-on event, so that "01" is set to the envelope phase data FZ of this n channel to indicate that it is the attack phase (step 406). This envelope phase data FZ
Is set to "01" in the attack phase, "10" in the decay phase, and "00" in the release phase.

Next, the envelope generator 14 outputs the target level data TL and the speed data SP corresponding to the envelope phase to the data table 4
It is read from 1 (step 408). At this time, the musical factor data is also used as a search element of the data table 41. In addition, one channel CH1 in the assignment memory 8 is generated by the envelope generator 14.
The envelope level data EN is read from and sent to the envelope generator 14. Since the envelope level data EN is cleared when the key-off event or the data during the mute is stored, the envelope level data EN is data indicating "0" level immediately after the key-on event. Then, by the envelope generator 14,
From these data, the envelope level EN of the attack phase of the tone of channel 1 is calculated (step 420). This calculation is performed, for example, by the following equation.

(TL−EN) × SP + EN → EN (1) Envelope level EN obtained by this calculation
Are updated and stored in one channel of the assignment memory 8.

Next, the musical tone waveform data MW is read from the musical tone waveform memory 13 (step 422) and the multiplier 16 is used.
Is multiplied by the envelope level data EN read again from the assignment memory 8 (step 424). The musical tone waveform data MW to which the envelope is given in this way is sent from the multiplier 16 to the accumulator 17 (step 426).

After that, when the channel assignment is repeated and the tone generation processing (step 400) is repeated for the same channel, the envelope level EN increases toward the target level TL of the attack phase and then reaches the target level TL. To reach. The envelope generator 14 determines this (step 42
8) Then, "10" indicating the decay phase is set in the envelope phase data FZ (step 430).
Thereafter, for channel 1 CH1, the target level data TL and speed data SP for the decay phase are read (step 408), and the operation of equation (1) is performed (step 420). As a result, thereafter, the envelope level EN decreases toward the target level TL of the decay phase.

When there is a key-off event for the tone of channel 1 CH1, the envelope generator 14
Discriminates this (step 410) and indicates "00" indicating the release phase in the envelope phase data FZ.
Are set (step 412). After that, for one channel, the target level data T for the release phase
L and speed data SP are read (step 41
4) and (1) are calculated (step 420).
As a result, the envelope level EN is attenuated toward the target level TL in the release phase every time the tone generation process (step 400) is repeated.
And it is muted. The envelope level EN and the envelope phase FZ are written in the corresponding channel memory area of the assignment memory 8.

The above-mentioned processing is performed on the other channels CH2 to CH.
Similarly, 16 is repeatedly performed sequentially or in a time division manner at high speed (steps 402 and 432). As a result, a musical tone envelope of the channel in which the key-on or sounding data is stored is formed. When the processing for 16 channels is completed, the channel number data n is reset (step 434).

6. Filter Control Process FIG. 8 is a flowchart of the filter control process (step 600). In this processing, note-on count processing (step 450) and range distribution discrimination processing (step 50)
0) and filter characteristic determination level calculation processing (step 55).
0) and the filter coefficient determination process (step 580) are sequentially executed, and the synthesized musical tone signal data S is generated in accordance with the number of keys pressed, the range of the keys turned on / off, and the on / off state of the damper.
A filter characteristic determination level AL for controlling the frequency characteristic of D is determined. Then, the filter coefficients a1 to an for variably setting the filter characteristics of the digital filter 18 are determined according to the magnitude of the filter characteristic determination level AL, and the filter coefficient data a1 to an are supplied to the coefficient memory 21.

[0038] 7. Note-on Count Process FIG. 9 shows the note-on count process (step 45 in FIG. 8).
It is a flowchart of (0). First, the CPU 5 clears the note-on count value data ONn in the register 32 (step 452). Then, the channel number data n is reset to "1" (step 45).
4). Next, 1 channel C of the assignment memory 8
It is determined whether or not the key-on data is stored in H1 (step 456), and if the key-on data is stored, "1" is added to the note-on count value data ONn (step 458).

Then, the channel number data is set to "1".
Incremented only (step 462) and then 2
After the same processing is performed for channels # 16 to CH2 to CH16, the next processing is performed (step 460). In this way, the number of depressed keys is obtained by counting the number of channels in which the key-on data is stored among the channels 1 to 16. The note-on count value ONn indicating the number of pressed keys is stored in the register 32.

Instead of the processing shown in FIG. 9, an interrupt processing started by a key-on event is provided.
Note-on count value data ON at key-on event
It is also possible to increment n by “1” and decrement the note-on count value data ONn by “1” at the time of a key-off event. Further, the note-on count value ONn may be corrected by addition or multiplication according to the number of reverberation sounds or the number of resonance sounds when the reverberation sound generation processing or the resonance sound generation processing is being performed.

8. Range distribution determination process FIG. 10 is a range distribution determination process (step 500) in FIG.
It is a flowchart of FIG. First, the CPU 5 clears the cumulative distribution coefficient data TEL of the register 34 (step 502) and increments the channel number data n of the register 39 by "1" (step 50).
4). Then, it is determined whether or not the key-on data is stored in the memory area CH1 of one channel (step 506). If the key is on, the key number data KN of the tone of channel 1 is read from the assignment memory 8 (step 508).

Then, the tone range distribution coefficient data EL corresponding to the key number data KN is obtained from the data table 50 (step 510). This data table 5
0 is stored in the RAM 6, for example, data showing the characteristics shown in FIG. 11 is stored. That is,
In the low range where the key number KN is small, the range distribution coefficient EL is large, and as the key number KN becomes larger, that is,
It is a characteristic that the range distribution coefficient EL becomes smaller as the pitch becomes higher.

The acoustic piano has thick and long strings in the low tone range and thin and short strings in the high tone range. For this reason,
Since the low-pitched tone has a long decay time, when the number of simultaneous pronunciations is large, a large number of low-pitched tone sounds are mixed and the tone is often unclear. On the other hand, since the high tone musical sound has a shorter decay time than the low tone musical sound, the musical tone is less obscured even when the number of polyphonic sounds is large. As described above, the data table 50 of FIG. 10 is determined in consideration of the fact that the decay time of the piano sound varies depending on the depressed key range.

The range distribution coefficient EL of FIG. 10 is
The shape is not limited to that shown in FIG.
Any shape such as a character shape, an M shape, a W shape, an N shape, an S shape, and a double mountain shape may be used. The range distribution coefficient EL is
In addition to those according to pitch (key number KN), octave code, tone number TN (tone), touch data,
It may be determined according to the effect data, the sound generation elapsed time, and the performance part. Further, this range distribution coefficient EL is
It may be obtained by addition / subtraction / multiplication of key number KN or the like, or calculation based on a calculation formula.

As described above, when the tone range distribution coefficient data EL corresponding to the key number data KN of channel 1 CH1 is obtained from the data table 50, the obtained tone range distribution coefficient data EL is stored in the register 33.
Then, the range distribution coefficient data EL is read again, and further the cumulative distribution coefficient data TEL is read from the register 34. These are added, and the addition result is stored in the register 34 as new cumulative distribution coefficient data TEL (step 512). On the other hand, if the tone of channel 1 is keyed off, the cumulative distribution coefficient TEL does not change.

The above steps 506 to 512 are similarly performed for the other channels CH2 to CH16 (steps 504 and 514). When the processing for 16 channels is completed, the cumulative distribution coefficient TEL becomes
It is the sum total of the range distribution coefficient EL of the channel where the key is on. Then, the channel number n is reset (step 516) and the process proceeds to the next process.

9. Filter Characteristic Determination Level Calculation Processing FIG. 12 is a flowchart of the filter characteristic determination level calculation processing (step 550) in FIG. In this process, a variable called the filter characteristic determination level AL for determining the filter coefficients a1 to an of the digital filter 18 is increased or decreased according to the number of key depressions, the musical range, and the operation of the damper pedal, which are the deciding factors related to the polyphony. To be done. First, C
The note-on count value data O obtained by the note-on count process (step 450) described above by the PU 5.
Nn is read from the register 32 (step 55)
2). Then, this note-on count value data ONn
The filter characteristic determination level AL corresponding to is obtained from the data table 60 and stored in the register 35 (step 556). This data table 60 is the RAM 6
The data is stored in, for example, data showing the characteristics shown in FIG. That is, the filter characteristic determination level AL increases to "1" or more when the note-on count value ONn exceeds the constant value K.

The note-on count value ONn is data indicating the number of pressed keys, and the musical tones of the keys being note-on are sounded at the same time.
Is the number of polyphonic sounds excluding the number of sound effects such as reverberation and resonance. Of course, the number of reverberations may be included. When the number of simultaneous pronunciations exceeds a certain value, the musical sound produced by the sound system 20 begins to become unclear. Therefore, the note-on count value O when this musical sound begins to become unclear
Let Nn be K. The filter characteristic determination level AL
May be obtained by addition, subtraction, multiplication and division of the note-on count value ONn or calculation based on a calculation formula.

When the filter characteristic determination level AL is obtained, the cumulative distribution coefficient TEL is next read from the register 34 (step 556), and the filter characteristic determination level AL is obtained.
(Step 558). This is a coefficient determined according to the note-on count value ONn of the filter characteristic determination level AL, that is, the number of keys on which the note-on is performed, and the coefficient is modified according to the range of the key having the key-on event. This is because As a result, the filter characteristic determination level AL is increased based on the increase in the number of depressed keys and the increase in the number of sounds generated by the musical range. The filter characteristic determination level AL after this correction is again set in the register 3
5 is stored.

As described above, the level control coefficient AL, which is obtained according to the number of keys pressed and corrected according to the range distribution, is further increased or decreased according to the on / off state of the damper pedal. After step 558, the CPU 5 reads the damper pedal on flag DF from the register 30 and determines whether the damper pedal on flag DF is set or reset (steps 560 and 566). Then, the correction constant DK is read from the register 31 (steps 562 and 568). Next, when the damper pedal on flag DF is set, the correction constant DK is added to the filter characteristic determination level AL corrected in step 558 (step 56).
4). When the damper pedal on flag DF is reset, the correction constant DK is subtracted from the filter characteristic determination level AL modified in step 558 (step 570).

In the acoustic piano, when the damper pedal is stepped on (damper pedal is on), the damping time of the musical sound produced when the damper is separated from all the strings becomes long, so that the tone generator 11 uses the damper pedal on flag DF. When is set, processing is performed so that the decay time of the musical tone of the depressed key and the musical tone that is already being sounded becomes long. For this reason, the number of simultaneous sounds increases and the tones to be sounded become unclear. To eliminate this, the filter characteristic determination level AL is corrected by the correction constant DK. Then, when the damper pedal is returned, the correction constant DK increased when the damper pedal is turned on is subtracted. The corrected filter characteristic determination level AL is stored in the register 35 again.

The above steps 558, 564, 57.
The addition / subtraction processing of 0 can be substituted by addition / subtraction multiplication / division, an operation based on an arithmetic expression, a data table read, or the like. Also,
The pedal 10 whose ON / OFF is determined in steps 560 and 566 may be a soft pedal, a sostenuto pedal, a mute pedal, a shifting pedal, a loud pedal, a foot switch, etc., in addition to the damper pedal.

10. Filter Coefficient Determination Process FIG. 14 shows the filter coefficient determination process (step 58 in FIG. 8).
It is a flowchart of (0). In this process, according to the magnitude of the filter characteristic determination level AL determined and corrected in the above-described filter characteristic determination level calculation processing (step 550), the filter coefficients a1 to
An decision is made. First, the CPU 5 reads the filter characteristic determination level AL from the register 35 (step 582).

Next, the filter coefficients a1 to an corresponding to the filter characteristic determination level AL are obtained from the filter coefficient table 70 provided in the RAM 6 (step 584). In the filter coefficient table 70, as shown in FIG. 15, a large number of sets of filter coefficients a1 to an are set according to the magnitude of the filter characteristic determination level AL. The filter coefficients a1 to an obtained from the filter coefficient table 70 are temporarily stored in the filter coefficient register 37.
After being stored in -1 to 37-n, the stored contents of the coefficient memory 21 are rewritten by being sent to the coefficient memory 21.

The digital filter 18 has a filter coefficient a.
By changing 1 to an, an all-pass filter (APF) having a flat frequency characteristic as shown in FIG. 16 (A) changes to a low frequency as shown in FIG. 16 (B) (C) (D). A band elimination filter (BE) having frequency characteristics in which the low and middle frequency bands of the middle frequency band are attenuation regions
It can be changed to F). That is, the smaller the filter characteristic determination level AL, the lower the attenuation rate in the low and middle frequency bands, and the higher the filter characteristic determination level AL, the higher the attenuation rate in the low and middle frequency bands. The filter characteristic of the digital filter 18 changes from the filter characteristic of FIG. 16A to that of FIG.
The filter characteristic of (D) changes in many stages. FIG.
(B) and (C) are filter characteristics at two points in the middle of the change.

Since the musical tone in the low tone range of the acoustic piano contains a lot of low and middle frequency components and has a long decay time, when the number of polyphony is large, the low and middle frequency components are not easily attenuated and are thus produced. Musical sounds may be unclear. Therefore, by attenuating the low and medium frequency components by the digital filter 18, the tones to be sounded are clarified. However, if the low and middle frequency components are attenuated uniformly, the low and middle frequency components may be unnecessarily attenuated when the polyphony is small, resulting in an unnatural musical sound. Decrease the attenuation rate or do not perform the attenuation as appropriate.

As described above, the attenuation rate of the digital filter 18 increases as the filter characteristic determination level AL increases. The filter characteristic determination level AL basically increases with an increase in the number of key presses, because the low and middle frequency components increase with an increase in the number of key presses. In addition, since the lower tone sounds include more low and middle frequency components, and the higher tone sounds include less low and middle frequency components, the tone distribution coefficient EL is determined as shown in FIG.
The filter characteristic determination level AL is corrected so as to increase as the number of tones in the low tone range increases (step 558 in FIG. 12). Furthermore, when the damper pedal is turned on, the decay time of the musical sound produced by the depression of the damper pedal becomes longer, and the low and medium frequency components increase.
The correction constant DK is added to increase the filter characteristic determination level AL (step 564 in FIG. 12).

As described above, in this embodiment, the attenuation rate of the digital filter 18 in the low and middle frequency bands is increased or decreased based on the number of keys pressed, the range of keys pressed, and the on / off state of the damper pedal. Thus, the low and middle frequency components included in the filtered synthetic tone signal SD are controlled to have an appropriate level.

11. Overall Circuit (Second Embodiment) FIG. 17 is an overall circuit in the second embodiment. In this embodiment, the synthesized musical tone signal SD output from the accumulator 17
Is converted into an analog signal by the DA converter 19 and then filtered by the voltage control filter 22. The voltage control filter 22 is an analog filter that can change the filter characteristic of the filter circuit by the variable voltage supplied from the voltage control circuit 23. The voltage control circuit 22 is a circuit that forms and outputs a voltage according to the voltage control data supplied from the CPU 5.

The CPU 5 is similar to that of the above-described embodiment and is shown in FIGS.
The processing of 10 and 12 is executed, and the filter characteristic determination level A
The voltage control data is formed so that the relationship between L and the filter characteristic of the voltage control filter 22 has the relationship shown in FIG. 16 and is supplied to the voltage control circuit 23. This embodiment also exhibits the same effect as the above embodiment. The voltage control filter 22 may be another analog filter, as long as the filter characteristic is variable.

12. Key event process (third embodiment ) Instead of the tone generation process (step 400), note-on count process (step 450), range distribution discrimination process (step 500), and filter characteristic determination level calculation process (step 550). The key event process (step 800) shown in FIG. 18 may be executed. In this process, the CPU 5 determines whether there is a key-on event or a key-off event (step 8).
02, 810). At the time of a key-on event, a key-on event process (step 804) is executed next. Next, the tone parameters are the tone generator 11 (sound source LS
I) is loaded (step 806). The musical tone parameters are envelope level data EN, target level data TL stored in the envelope memory 15, speed data SP, musical tone waveform data MW stored in the musical tone waveform memory 13, and the like. When these parameters are read out, a tone generation process (step 808) is performed next. In this pronunciation processing, the target level data TL,
Speed data SP, envelope level data EN,
A tone signal is formed based on the tone waveform data MW and sent to the accumulator 17. The tone generator LSI is an LSI inside the tone generator 11.

On the other hand, when there is a key-off event, the damper pedal on flag DF is followed by step 810.
Is set (step 81).
2). Then, if the damper pedal on flag DF is set, the process proceeds to other processing (step SJ). When the damper pedal on flag DF is reset, the damper pedal is not depressed, so
The tone of the key that had the key-off event is transferred to the release phase. This is because the release level target level data TL and the speed data SP are read from the envelope memory 15 and the tone generator L in the tone generator 11 is read.
This is performed by the process of loading the SI (step 81).
4). Then, the key-off event process is executed (step 816).

The above key-on event process is a process as shown in FIG. First, the note-on count value ONn is incremented (step 820). Then, the range distribution determination processing (step 500) of FIG. 10 is performed, and the range distribution coefficient EL corresponding to the range of the key having the key-on event is obtained (step 822).
Then, the note-on count value ONn and the range distribution coefficient E
The filter characteristic determination level AL is determined by L and L (step 824). This filter characteristic determination level A
For L, for example, a standard parameter constant TAL is determined in advance, and the standard parameter constant TAL is calculated by modifying the note-on count value ONn and the range distribution coefficient EL, or ONn and EL are used as parameters. It is determined by the process of reading from the data table. The range distribution constant EL acts in the direction of increasing the standard parameter TAL at the key-on event. The determined filter characteristic determination level AL is stored in the register 35.

FIG. 20 is a flowchart of the key-off event process. First, the note-on count value ONn is decremented (step 830). And FIG.
Zero range distribution discrimination processing (step 500) is performed,
A range distribution coefficient EL corresponding to the range of the key having the key-off event is obtained (step 832). Then, the filter characteristic determination level AL is determined by the note-on count value ONn and the range distribution coefficient EL (step 834). At the time of this key-off event, the range distribution coefficient EL acts in the direction of decreasing the standard parameter TAL. This determined filter characteristic determination level AL is stored in the register 35.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the spirit of the present invention. For example, in the above-described embodiment, the filter characteristic determination level AL is determined based on the number of keys pressed, the range of the key that was on / off, and the on / off of the damper pedal. It may be determined based only on the pitch range or pitch and only on / off of the damper pedal. Also, the number of keys pressed and the range or pitch, the number of keys pressed and the damper pedal on / off,
It may be determined based on the range or pitch and on / off of the damper pedal. This is because they are all related to the increase / decrease in the polyphony.

In the note-on count process (step 450) of FIG. 9, the number of channels in which the key-on data is stored is counted (step 45).
6) Then, as shown in FIG. 21, the number of channels in which the data being sounded is stored may be counted (step 470). As a result, it is possible to perform control in consideration of the number of simultaneous sounds when there is a musical sound to be sounded even if the key is not pressed. This is because, depending on the model, one key may use a plurality of channels, and the number of channels used may change depending on the tone color setting (for example, piano, organ, harpsichord, etc.).

Further, the filter characteristic determination level AL is not limited to the one determined by the relationship like the data table 60 shown in FIG. For example, as shown by D1 and D2 in FIG. 22, the relationship may be such that it increases in a curve when the note-on count value ONn is a certain value K or more.
As shown in D3, D4, and D5 of No. 2, the relationship may be such that the constant value P increases in a curved or linear manner as the note-on count value ONn increases.

Further, in the above-mentioned embodiment, the electronic musical instrument for simulating the generated sound of the acoustic piano has been described, but the present invention can be applied to the electronic musical instrument for generating the generated sound of instruments other than the piano. In this case, the keyboard 1 may be replaced by an electronic string instrument, an electronic wind instrument (lead) instrument, an electronic percussion (pad) instrument, a computer keyboard, or the like. The correction of the filter characteristic determination level AL based on the ON / OFF state of the damper pedal can be applied to the case where a generated sound of an instrument having a damper function such as a marimba is generated in addition to the piano.

Furthermore, in the above-described embodiment, the electronic musical instrument that performs the process of generating the sound effect such as the reverberation sound generating process and the resonance sound generating process is shown, but the electronic musical instrument that does not perform these processes may be used. In this case, at least the key-on number is detected and the filter characteristic determination level AL is determined.

Further, even if the key of the keyboard 1 is turned off by turning on the damper pedal, the key off event process is not performed, and the number of simultaneously sounded notes, that is, the note-on count value data ONn is prevented from decreasing, and by turning off the damper pedal, Key off event processing of the key that was off while the damper pedal was on
For the first time, the note-on count value data ONn may match the number of ON keys. In this case, the mute processing of FIG. 1 of Japanese Patent Application No. 3-85225, the overall processing of FIG.
The process shown in the flowchart of the panel process of FIG. 7 is C
This is performed by PU5.

It goes without saying that a digital filter and an analog filter may be combined. Further, the frequency characteristic of the filter circuit is not limited to the characteristic having the attenuation band in the low and middle frequency band as described above, and a high pass filter, a low pass filter or a band pass filter, and a plurality of attenuation bands in different frequency bands are provided. It may be a band cutoff filter provided. Further, instead of the filters 18 and 22, a circuit for changing the frequency characteristic of the musical tone signal, such as an equalizer IC or a brilliance circuit using an analog circuit, may be used.

The digital filter 18 has a CP
It may be a digital filter configured by software executed by the CPU or DSP in the U5 or tone generator 11. In this case, the accumulator 1
An input interface for inputting the synthesized tone signal SD output from the CPU 7 to the CPU 5 and the like and an output interface for supplying the synthesized tone signal SD after the filtering process from the CPU 5 to the DA converter 19 are provided. The digital filter configured by this software can change not only the filter coefficient but also the filter configuration by switching between FIR and IIR or changing the order.

In the above embodiment, the filter characteristic is determined according to the level of the filter characteristic determination level.
However, the present invention is not limited to this. For example, based on determinants related to increase / decrease in the number of simultaneous sounds, such as the number of keys pressed, the range or pitch of the tones to be sounded, on / off of an effect adding device such as a damper pedal, It may be determined according to the calculation result of a predetermined calculation formula (may be a calculation circuit), or appropriate filter characteristics may be determined from a preset data table.

Further, in each of the above-described embodiments, the same processing can be performed by replacing the tone range (key number data KN) with pitch, tone color (tone number data TN) or touch data. In this case, the range distribution coefficient EL of FIG. 11 becomes a pitch distribution coefficient, a tone color distribution coefficient, or a touch distribution coefficient.

[0075]

As described above, according to the present invention, the number of key-on, the range or pitch of the key-on / off, or the number of simultaneous sounds such as on / off of the damper or the increase / decrease of the number of simultaneous sounds are determined. A factor is detected, and the filter characteristic of the filter means for filtering the synthesized tone signal is appropriately variably set based on the determinant. As a result, when the polyphony is increased, the frequency component of the specific band in the musical tone to be pronounced is attenuated to prevent the musical tone from being unclear, and when the polyphony is reduced, the musical tone to be sounded is reduced. By stopping or suppressing the attenuation operation of the frequency component of the specific band, it is possible to generate a natural musical sound without a feeling of strangeness.

Further, according to the present invention, the ambiguity of the musical tone is removed by attenuating the frequency component of the specific band. Therefore, the envelope shape of the musical tone signal is deformed or each musical tone to be sounded is generated. Since the time and decay time are not changed, the note length does not change and accurate performance can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is an overall circuit diagram of the electronic musical instrument of the first embodiment.

FIG. 3 is a diagram showing an assignment memory 8.

FIG. 4 is a diagram showing a register group and a data table.

FIG. 5 is a diagram showing a flowchart of overall processing.

FIG. 6 is a diagram showing a flowchart of pedal event processing.

FIG. 7 is a diagram showing a flowchart of a musical sound generation process.

FIG. 8 is a diagram showing a flowchart of filter control processing.

FIG. 9 is a diagram showing a flowchart of a note-on count process.

FIG. 10 is a diagram showing a flowchart of a range distribution determination process.

FIG. 11 is a diagram showing a range distribution coefficient table.

FIG. 12 is a diagram showing a flowchart of a filter characteristic determination level calculation process.

FIG. 13 is a diagram showing a filter characteristic determination level table 60.

FIG. 14 is a diagram showing a flowchart of filter coefficient determination processing.

FIG. 15 is a diagram showing a filter coefficient table 70.

FIG. 16 is a diagram showing a relationship between a filter characteristic determination level and a filter characteristic.

FIG. 17 is a diagram showing an overall circuit of a second embodiment.

FIG. 18 is a diagram showing a flowchart of key event processing.

FIG. 19 is a diagram showing a flowchart of key-on event processing of the third embodiment.

FIG. 20 is a diagram showing a flowchart of key-off event processing.

FIG. 21 is a view showing a flowchart of another example of the note-on count processing.

22 is a diagram showing another example of the filter determination level table 60. FIG.

[Explanation of symbols]

M1 ... Musical sound generation instruction means, M2 ... Musical sound signal generation means, M
3 ... Filter means, M4 ... Determinant detection means, M5 ... Filter control means, 1 ... Keyboard, 5 ... CPU, 8 ... Assignment memory, 10 ... Pedal, 11 ... Tone generator, 14 ... Envelope generator, 15 ... Envelope memory , 16 ... Multiplier, 17 ... Accumulator, 18
... Digital filter, 19 ... DA converter, 20 ... Sound system, 21 ... Coefficient memory, 22 ... Voltage control filter, 23 ... Voltage control circuit, 30-37 ... Register, 4
0, 50, 60, 70 ... Data table.

Claims (7)

[Claims] 1. A plurality of tone generation instruction means for instructing the generation of a tone, a tone signal generation means for generating a tone signal according to each instruction of the plurality of tone generation instruction means, and the tone signal generation means. The filter means for filtering the generated tone signal has a variable filter characteristic, the determinant detecting means for detecting the determinant for determining the filter characteristic of the filter means, and the determinant detecting means for detecting the determinant. A frequency characteristic control device for a musical tone signal, comprising: a filter control means for variably setting a filter characteristic of the filter means based on a determinant. 2. The frequency characteristic control device for musical tone signals according to claim 1, wherein said determinant detecting means detects the number of musical tone generation instructing means instructed. 3. The frequency characteristic control device for a musical tone signal according to claim 1, wherein said determinant detecting means detects a musical range or pitch of said designated musical tone generation instructing means. 4. The frequency characteristic control device according to claim 1, wherein the determinant detecting means detects whether the damper pedal is on or off. 5. The frequency characteristic control device for musical tone signals according to claim 1, wherein the filter means is a digital filter. 6. The frequency characteristic control device for musical tone signals according to claim 1, wherein said filter means is an analog filter. 7. A frequency characteristic control device for musical tone signals according to claim 1, wherein said filter means attenuates frequency components in a specific band.