JP2000250540A - Musical sound controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily realize tone color changes caused by the reduction in fundamental sounds such as an acoustic piano and an electric piano, with a simple and inexpensive constitution with respect to a keyboard electronic musical instrument. SOLUTION: A storage means is arranged in a filter coefficient computing means 9 to beforehand store filter coefficient corresponding to the frequencies of each sound pitch inputted from a key pressing information generating means 1. While executing filtering computations for the waveform data of a fundamental sound and plural double sounds, filtering coefficients are computed for the waveform data of the fundamental sound and the double sounds, that are specified as the objects of the filtering computation, based on the ratio between the frequencies determined by the frequencies of the inputted pitch and the frequencies determined by the double sounds specified by a double sound specifying means 7 and the frequencies corresponding to the beforehand stored filtering coefficients.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone control device for giving a tone color change to a tone signal.

[0002]

2. Description of the Related Art In an acoustic piano, it is possible to easily produce a tone change in which a fundamental tone is lost as time elapses from the start of sounding. Further, in an electric piano, it is possible to easily create a timbre change in which the volume of a fundamental tone is reduced when a strong touch is made.

[0003]

However, a keyboard electronic musical instrument such as a synthesizer has a problem that it is difficult to produce a tone change like an acoustic piano or an electric piano. For example,
The spectrum of the tone signal of the 440 Hz A4 key is 44
0Hz fundamental, 880Hz 2nd harmonic, 1320Hz 3
Overtones, 1760 Hz fourth harmonics ... In this case, to decrease the gain of the waveform data of the fundamental tone of 440 Hz, a filter coefficient for decreasing the gain of the frequency of 440 Hz is calculated on the waveform data, and the gain of the waveform data of the second harmonic of 880 Hz is decreased. A filter coefficient for lowering the gain at the frequency of 880 Hz is calculated on the waveform data.

[0004] That is, it is necessary to store the filter coefficients by the number of keys and the number of harmonics to the fundamental tone of each key.
For example, in an 88-key keyboard electronic musical instrument, a fundamental tone and an 8
When storing filter coefficients for waveform data up to harmonics, nine filter coefficient parameters are required for each pitch, and a total of 792 filter coefficient parameters are stored in advance. There is a need. For this reason, the storage capacity for storing the parameters of the filter coefficients becomes enormous, which hinders cost reduction and miniaturization.

[0005] Therefore, there has been proposed a method of reducing the number of bandpass filters by using a key follow function. The key follow function is a function of preventing the tone color from changing due to a change in the overtone relationship according to the key number, that is, the pitch, input from the keyboard. The cutoff frequency is changed for each input pitch so that the harmonic relationship does not change. However, in order to reduce only the fundamental or harmonic waveform data specified by the key follow function, it is necessary to clarify the relationship between the key follow data and the parameter of the filter coefficient, and it is difficult for the user to perform this. is there. Also, on the manufacturer side, development time and human resources are required, and sufficient results have not been obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a keyboard electronic musical instrument such as a synthesizer or the like with a simple and inexpensive configuration to easily realize a rich tone change.

[0007]

According to the present invention, there is provided a waveform generating means for generating waveform data of a fundamental tone corresponding to an input pitch and waveform data of a plurality of overtones with respect to the fundamental tone; Harmonic designation means for designating a fundamental tone or one of a plurality of harmonics, a storage means for storing in advance a filter coefficient corresponding to the frequency of each input pitch, and a fundamental tone designated by the harmonic designation means. A filter for performing a filtering operation on the waveform data of the specified fundamental or harmonic generated by the waveform generating means based on a ratio between the frequency of the harmonic and the frequency corresponding to the filter coefficient stored in the storage means. And a filter coefficient calculating means for calculating a coefficient.

According to the present invention, when performing a filtering operation on waveform data of a tone signal composed of a fundamental sound and a plurality of overtones, the frequency of the fundamental sound or the overtone designated as the object of the filtering operation and the filter stored in advance Based on the ratio of the coefficient to the frequency corresponding to the coefficient, a filter coefficient for the waveform data of the fundamental tone or the overtone specified as the target of the filtering operation is calculated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tone control device according to the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a block diagram illustrating a system configuration of a tone control device according to the embodiment. The keyboard information generating means 1 generates a key number, that is, a pitch, of a tone signal input by keyboard performance, and velocity data indicating the strength of key depression. For example, when the A4 key is pressed, pitch (frequency) data and velocity data of 440 Hz are generated. A
When the third key is depressed, pitch data and velocity data of 220 Hz are generated.

The waveform generating means 2 reads out the waveform data from the waveform memory 3 based on the pitch data from the keyboard information generating means 1. Since the waveform memory 3 stores the PCM waveform data corresponding to the timbre, the PCM waveform data corresponding to the set timbre is read out based on the pitch data, and is read as the waveform data of the fundamental tone and a plurality of harmonics. Output to the filter operation means 4. For example, when the pitch data of the fundamental tone is A4, the spectrum of the waveform data read from the waveform memory 3 is as shown in FIG. When the pitch data of the fundamental tone is A3, the spectrum of the waveform data read from the waveform memory 3 is as shown in FIG. 2 and 3, the horizontal axis represents frequency, and the vertical axis represents gain.

In FIG. 1, a filter operation means 4 performs a filtering operation on the waveform data output from the waveform generation means 2 and outputs the result to a volume operation means 5. The sound volume calculating means 5 calculates the sound volume at the start of sound generation based on the velocity data from the key press information generating means 1, and controls the sound volume after the sound generation is started based on the envelope data from the sound volume envelope setting means 6. (Not shown).

The overtone designating means 7 designates a fundamental tone or an arbitrary harmonic by a number. “1” is a fundamental tone, “2” is a number that designates a second harmonic, and “3” is a number that designates a third harmonic. In this embodiment, “1” is set in advance, and the fundamental tone is designated. The multiplier 8 multiplies the frequency data from the key press information generating means 1 by the data from the overtone specifying means 7 and inputs the result to the filter coefficient calculating means 9. In this case, the data from the overtone specifying means 7 is "1".
(Fundamental tone) ”, the frequency data of the fundamental tone of the depressed key is directly input to the filter coefficient calculating means 9.

The filter coefficient calculating means 9 stores filter coefficient parameters corresponding to the frequency of the inputted pitch. Further, a gain parameter is input from the filter gain specifying means 10 to the filter coefficient calculating means 9. The gain parameter in this case is "-
6 db ", and a parameter for reducing the gain of the waveform data to １ ／ is set. Therefore, as shown in FIG. 4, a parameter of a filter coefficient for lowering the gain of the waveform data of the designated frequency is output from the filter coefficient calculating means 9, and is input to the filter calculating means 4.

Next, the operation of the tone control device in the embodiment will be described. For example, when the key A4 is depressed by playing the keyboard, data of a frequency of 440 Hz is input to the filter coefficient calculating means 9 from the key pressing information generating means 1 via the multiplier 8. Filter coefficient calculation means 9
Performs an operation of 440 Hz / 440 Hz = 1, and inputs the filter coefficient parameters shown in FIG. 4 to the filter operation means 4 based on the stored filter coefficient parameters and the gain parameter of “−6 db”.

In this case, the filter operation means 4 includes:
The spectrum of the waveform data A4 shown in FIG. As a result, the spectrum of the waveform data input from the filter calculation means 4 to the volume calculation means 5 is a spectrum in which the gain of the waveform data of the fundamental tone of 440 Hz is reduced to half as shown in FIG.

When the key A3 is depressed by the keyboard performance, the key depression information generation means 1 passes through the multiplier 8 to
Data having a frequency of 0 Hz is input to the filter coefficient calculating means 9. The filter coefficient calculating means 9 is 220 Hz / 4
By performing an operation of 40 Hz = １ ／, a new filter coefficient parameter is calculated based on the stored filter coefficient parameter, and the calculated filter coefficient parameter and a gain parameter of “−6 db” are used.
The parameters of the filter coefficients shown in FIG.

In this case, the filter operation means 4 includes:
The spectrum of the waveform data of A3 shown in FIG. As a result, the spectrum input from the filter operation means 4 to the volume operation means 5 is as shown in FIG.
As shown in (2), the spectrum has a waveform in which the gain of the waveform data of the fundamental tone at 220 Hz has been reduced by half.

Similarly, when any other key n is depressed by playing the keyboard, the spectrum data of the fundamental tone having the frequency f corresponding to the key n is input to the filter coefficient calculating means 9. The filter coefficient calculating means 9 calculates fHz / 440 Hz =
The f / 440 calculation is performed to calculate new filter coefficient parameters based on the stored filter coefficient parameters, and the calculated filter coefficient parameters and the gain parameter of “−6 db” are calculated by the filter calculation means. Enter 4

As described above, in the above-described embodiment, the filter coefficient calculating means 9 is provided with the storage means for storing in advance the filter coefficients corresponding to the frequencies of the respective pitches inputted from the key press information generating means 1. When performing a filtering operation on waveform data of a tone signal composed of a fundamental sound and a plurality of overtones, the ratio of the frequency of the fundamental sound or the overtone designated as the target of the filtering operation to the frequency corresponding to the filter coefficient stored in advance. , A filter coefficient for the waveform data of the fundamental tone or the overtone specified as the target of the filtering operation is calculated. Therefore,
In a keyboard electronic musical instrument such as a synthesizer, a rich and varied timbre can be easily realized with a simple and inexpensive configuration.

In this case, the filter coefficient calculating means 9 is configured to calculate a filter coefficient at which the gain of the waveform data of the fundamental tone decreases with time. With such a configuration, it is possible to easily realize a timbre change, such as an acoustic piano, in which a fundamental tone escapes with a simple and inexpensive configuration.

Alternatively, in this case, the filter coefficient calculation means 9 is configured to calculate a filter coefficient in which the gain of the waveform data of the fundamental tone changes according to the velocity data of the tone signal. With such a configuration, it is possible to easily realize a tone color change in which the volume of the fundamental tone is reduced at the time of a strong touch such as an electric piano with a simple and inexpensive configuration.

In the above embodiment, the filter coefficient for reducing the gain of the fundamental tone waveform data is calculated. However, the waveform data to be subjected to the filtering operation is not limited to the fundamental tone. That is, the overtone specifying means 7
Can specify not only the fundamental tone but also an arbitrary harmonic, so that the filtering operation can be performed on the waveform data of the specified harmonic, and the gain can be arbitrarily controlled by the filter gain specifying means 10.

[0023]

According to the present invention, when performing a filtering operation on the waveform data of a tone signal composed of a fundamental sound and a plurality of harmonics, the frequency of the fundamental sound or the overtone designated as the target of the filtering operation is stored in advance. The filter coefficient for the waveform data of the fundamental tone or the overtone specified as the target of the filtering operation is calculated based on the ratio of the filter coefficient to the frequency corresponding to the filter coefficient. Therefore, in a keyboard electronic musical instrument such as a synthesizer, a rich tone change can be easily realized by a simple and inexpensive configuration.

[Brief description of the drawings]

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

FIG. 2 is a view showing a spectrum of an A4 tone signal output from the waveform generating means of FIG. 1;

FIG. 3 is a view showing a spectrum of an A3 tone signal output from the waveform generating means of FIG. 1;

FIG. 4 is a waveform diagram of a band-pass filter for an A4 tone signal input to the filter operation means of FIG. 1;

FIG. 5 is a view showing a spectrum of an A4 tone signal output from the filter operation means of FIG. 1;

FIG. 6 is a waveform diagram of a band-pass filter for an A3 tone signal input to the filter operation means of FIG. 1;

FIG. 7 is a view showing a spectrum of an A3 tone signal output from the filter operation means of FIG. 1;

[Explanation of symbols]

 1 Key press information generating means 4 Filter calculating means 7 Overtone specifying means 9 Filter coefficient calculating means

Claims (3)

[Claims] 1. A waveform generating means for generating waveform data of a fundamental tone corresponding to an inputted pitch and waveform data of a plurality of harmonics for the fundamental tone, and one of a fundamental tone or a plurality of harmonics according to an inputted pitch. Harmonic designation means for designating the frequency, a storage means for storing in advance filter coefficients corresponding to the frequencies of the respective pitches to be inputted, and a frequency of the fundamental tone or harmonic designated by the harmonic designation means and the storage means. Filter coefficient calculation means for calculating a filter coefficient for performing a filtering calculation on the waveform data of the designated fundamental tone or harmonic generated from the waveform generation means based on a ratio of the stored filter coefficient to a frequency corresponding to the stored filter coefficient. And a musical tone control device comprising: 2. The filter coefficient calculating means according to claim 1, wherein said filter coefficient calculating means calculates a filter coefficient with which a decrease in gain of said fundamental tone waveform data increases with time.
A musical tone control device according to claim 1. 3. The tone control device according to claim 1, wherein said filter coefficient calculating means calculates a filter coefficient in which a gain of the waveform data of the fundamental tone changes according to velocity data of the tone signal. .