JPH0635463A - Electronic musical instrument - Google Patents

Abstract

PURPOSE:To possess a musical sound which reaches a listener of desired frequency characteristics in spite of the transmission characteristics of outside environment. CONSTITUTION:A musical sound signal generation part 3 generates a musical sound signal corresponding to a timbre and a pitch name which are specified. Then a filter 7 controls the frequency characteristics of the musical sound signal on the basis of set parameters and a speaker 11 outputs the output signal of the filter as a musical sound. A microphone 12 reinputs a musical sound after its frequency characteristics vary owing to the outside environment and converts it into a signal. A data supply part 5 supplies data regarding the desired frequency characteristics to an arithmetic part 6. The arithmetic part 6 calculates and generates parameters controlling the frequency characteristics of the filter 7 from the data and the signal from the microphone 12. Consequently, the filter 7 controls the frequency characteristics of the outputted musical sound signal so that variation caused by indoor environment is compensated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument in which, for example, the frequency characteristic of a musical tone becomes a desired frequency characteristic depending on the environment.

[0002]

2. Description of the Related Art Conventionally, an electronic musical instrument having a built-in speaker and having functions such as an equalizer and an effector is known. In this electronic musical instrument, the frequency characteristic of the musical sound to be output can be freely changed by adjusting and setting various parameters such as an equalizer.

By the way, when the listener (performer) is away from the speaker, the musical sound that reaches the listener's ear is not limited to that directly coming from the speaker, but also is reflected at the wall in the room and has a specific frequency. Some bands are amplified or attenuated. In other words, the frequency characteristic of the musical sound produced by the speaker changes depending on the external environment such as the indoor environment before reaching the listener's ear. Therefore,
The listener will hear a musical tone having a frequency characteristic different from that actually output from the speaker. Therefore, in order to correct the change in the frequency characteristic of the musical sound, the listener adjusts various parameters such as an equalizer in advance so that the frequency characteristic of the musical sound reaching the ear becomes a desired one.

[0004]

However, every time there is a change in the listening environment or a change in the external environment such as a movement of the installation location, it is necessary to adjust the musical tone to have a desired frequency characteristic. In this case, since the listener has to reset various parameters, there is a problem that a great deal of time and effort is required. The present invention has been made in view of the above problems, and an object of the present invention is to control the frequency characteristic of a musical tone signal to be output so as to compensate for the frequency characteristic variation due to the environment, and to generate a musical tone that reaches a listener. The purpose is to provide an electronic musical instrument that satisfies the requirements.

[0005]

In order to solve the above-mentioned problems, the present invention provides a tone signal generating means for producing a predetermined tone signal and a filter for filtering the tone signal with a characteristic defined by a filter coefficient. Means, an output means for outputting a musical sound based on the musical sound signal filtered by the filter means, an input means for inputting the musical sound by the output means and converting it into a signal, and at least one data regarding a desired frequency characteristic. One or more storage means for selectively supplying the data, and a filter for arithmetically generating the filter coefficient from the data supplied from the storage means and the signal from the input means and supplying the filter coefficient to the filter means. And a control means.

[0006]

According to the above-mentioned structure, the musical tone output by the output means is taken in again by the input means and converted into a signal after the frequency characteristic is changed by the external environment. The filter control means controls the filter means by arithmetically generating a filter coefficient from the signal and the data of the storage means so as to compensate the transfer characteristic between the output means and the input means. Based on this filter coefficient, the filter means changes the frequency characteristic of the tone signal. Further, it is possible to control a musical tone reaching the listener to have a desired frequency characteristic by pre-storing a plurality of data indicating the desired frequency characteristic in the storage means and selecting the data. Become.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the electrical configuration of the electronic musical instrument of this embodiment. In this figure, reference numeral 1 denotes a keyboard device composed of a keyboard and switches corresponding to each key, etc., and detects the release of a key operated by a performer, and detects a signal key-on KON corresponding to a key press or a key release. A corresponding key-off KOFF, a signal key code KC indicating a pitch corresponding to a key depression, etc. are generated.

Reference numeral 2 is an operation panel for setting tone colors and rhythms. On the operation panel 2, as shown in FIG.
Rhythm selecting switches 2 _{1 to} 2 ₃ , rhythm start / stop instructing switch 2 ₄ and timbre selecting switches 2 ₅ to 2 ₈ are provided respectively. The indicated signal is generated.
That is, these signals are START / STOP corresponding to a rhythm start / stop instruction, a tone color code TC indicating a tone color to be sounded, and a genre code JC corresponding to a rhythm type.

Returning to FIG. 1 again. Reference numeral 3 is a tone signal generation unit that generates tone signals of tone pitches corresponding to the key code KC and tone colors corresponding to the tone color code TC in accordance with the key-on KON and the key-off KOFF. Supply to one input terminal of S. Meanwhile, 4 is a rhythm signal generating unit, when it is instructed rhythm started by the switch 2 _4, and generates a rhythm signal corresponding to a genre code JC, supplied to the other input terminal of the adder S.

In the adder S, the tone signal and the rhythm signal are added and supplied to the following input terminals. These input terminals are the input terminal B of the data supply unit 5, the arithmetic unit 6, the filter 7, and the selector 8. Where adder S
Let x (n) be the result of addition (n represents the time slot numbers 0, 1, 2, ... Corresponding to the sampling period). The data supply unit 5 stores the ideal frequency characteristic of the musical sound heard by the listener for each genre selectable on the operation panel 2, and has, for example, a filter, and the genre code JC is added to the addition result x (n). Frequency characteristic based on the calculated signal d (n).
Supply to. Here, the ideal frequency characteristic for each genre is, for example, preferably a uniform characteristic over the entire range in the case of jazz, and a characteristic in which the high range is emphasized in the case of rock. Say etc.

The arithmetic unit 6 is composed of an adder, a parameter supplying unit and an estimated value giving unit, which will be described later, and its internal configuration changes depending on the operating state. The arithmetic unit 6 generates an error signal e described below from the signals supplied to the respective input terminals by these respective units, and the filter 7 is generated based on the error signal e.
And outputs a signal SLTA for controlling the selection of the selector 8. The filter 7 controls the frequency characteristic of the addition result x (t) based on the multiplication coefficient, and supplies this output signal to the arithmetic unit 6 and the input terminal A of the selector 8.

The selector 8 selects one of the data supplied to the input terminals A and B based on the signal SLTA supplied to the select terminal SA and outputs it. The signal SLTA is "1". At this time, the input terminal A is selected. The output of the selector 8 is the D / A conversion unit 9
After being converted into an analog signal by, the signal is amplified by the amplifier 10 and output as a musical sound through the speaker 11. The musical sound from the speaker 11 is converted into an electric signal by the microphone 12, is amplified by the amplifier 13, is further converted into a digital signal by the A / D converter 14, and is supplied to the calculator 6. Here, the microphone 12 is installed in a place for listening to a musical sound.

Next, the detailed structure of the filter 7 will be described with reference to FIG.
Will be described with reference to. In this figure, D is a delay element that delays the input data by one sampling cycle. Here, when m is a positive integer, the delay elements D are cascade-connected (m-1) as shown in this figure, and a general delay result x (n-i) (i = 0).
.About.m-1) are respectively supplied to the multipliers M _i . Then, each of the multipliers M _{0 to} M _{m− 1} multiplies the coefficients w (0) to w (m−1) supplied from the calculation unit 8, respectively. The multiplication results of the multipliers M _{0 to} M _m-1 are added by the adder A and supplied as the signal y (n) of the filter 7. In the structure of such a filter 7,
The signal y (n) is given by the following equation.

[0014]

[Equation 1]

That is, in the filter 7, the coefficient w (0)
By changing w (m-1), the addition result x
The frequency characteristic of (n) can be changed.

Next, the operation of this embodiment will be described. First, in this embodiment, the transfer characteristic H between the speaker 11 and the microphone 12 is calculated to obtain the estimated characteristic H '. After that, in the embodiment, the tone characteristic output from the speaker 11 is provided with the inverse characteristic of the estimated characteristic H'in advance to compensate for the change in the frequency characteristic due to the external environment. These will be described in detail below.

First, in order to estimate the transfer characteristic H, the arithmetic unit 6 sets the signal SLTA to "0" and causes the selector 8 to select the input terminal B. At this time, in the present embodiment, as the addition result x (n), a musical tone signal by a keyboard performance or an automatic rhythm is used. This is because the keyboard performance sound or the automatic rhythm sound can be generated over a wide frequency band. For example, a noise generator may be provided and a white noise signal having a flat characteristic over the entire frequency band may be used. FIG. 2 shows the configuration of FIG. 1 in this state, in particular, the latter part after the adder S is simplified, and for convenience of explanation, a part where the frequency characteristic does not change (selector 8, D / A converter 9, amplifier 10). , 13, and the A / D converter 14) are omitted. The same parts as those in FIG. 1 are designated by the same reference numerals.

As shown in the figure, when the input terminal B is selected by the selector 8, the addition result x (n) is supplied to the filter 7 and the arithmetic unit 6 and is sounded by the speaker 11. At this time, if the signal taken in by the microphone 12 is h (n), this signal h
(N) is obtained by adding the transfer characteristic H to the addition result x (n).

Next, the calculation section 6 calculates an error signal e in the adder 61, which is e = h (n) -y (n), and supplies it to the parameter supply section 62. The transfer characteristic H can be estimated by setting the combination of the multiplication coefficients w (i) of the filter 7 such that the error signal e is minimized. In general, the error signal e
In order to minimize the square of, the filter coefficient w ′ (i) to be newly supplied may be calculated by an adaptive process using the least square method (LMS method), that is, by using the following equation. It is known.

[0020]

[Equation 2] However, i = 0 to m-1

In this equation, μ is a coefficient that determines the speed of convergence of the multiplication coefficient w (i). For example, when the value of the coefficient μ is very small, it converges to the minimum point without vibration in the adaptation process, but the adaptation speed becomes slow. On the other hand, the coefficient μ
If the value of is very large, overshoot may occur at each step in the adaptation process and diverge, but the adaptation speed becomes faster. The value of such coefficient μ is set to an appropriate value by a switch volume or the like not shown. Although the addition result x (n) input to the parameter supply unit 62 is sequentially stored in x (n-i), each delay result of the filter 7 may be used. In this way, the set of multiplication coefficients w (i) of the filter 7 that minimizes the error signal e is stored in the storage unit (not shown) in the calculation unit 6, and the transfer characteristic H is estimated. The estimated characteristic of the transfer characteristic H thus estimated is H '.

After the completion of the estimation of the transfer characteristic H, the arithmetic unit 6 sets the signal SLTA to "1" to cause the selector 8 to select the input terminal A. At this time, as the addition result x (n), the addition signal of the rhythm sound by the rhythm signal generator 4 and the tone signal generator 3 is used. That is, a normal performance sound is used. FIG. 3 is a simplified version of the configuration of FIG. 1 in this state, and the same parts as those in FIG. 1 are designated by the same reference numerals. As shown in this figure, the addition result x (n) is
It is supplied to the filter 7, the calculation unit 6, and the data supply unit 5. The addition result x (n) supplied to the data supply unit 5 is given a frequency characteristic corresponding to the genre code JC supplied from the operation panel 2 to the data supply unit 5, and added as a target signal d (n). Is supplied to one input end of the container 61. Here, when the frequency characteristic corresponding to the genre code JC is D, d (n) is d (n) = D · x (n).

The addition result x supplied to the filter 7
A predetermined frequency characteristic is given to (n), and the signal y
It is output as (n). The signal y (n) is output by the filter 7, the frequency characteristics thereof are changed by the external environment, and the signal y (n) is captured by the microphone 12 as the signal h (n). That is, the signal h (n) is obtained by adding the transfer characteristic H to the output signal y (n) of the filter 7, and therefore h (n) = H · x (n).

Further, in the adder 61, an error signal e of e = h (n) -d (n) is calculated and supplied to one input end of the parameter supply unit 62.

On the other hand, to the addition result x (n) supplied to the parameter supply unit 62, the above-mentioned estimated characteristic H'of the transfer characteristic H is added by the estimated value addition unit 63 composed of a filter, for example. . Here, the signal to which the estimated characteristic H ′ is added is x ′ (n). Parameter supply unit 62
Calculates a coefficient w ′ (i) that minimizes the square of the error signal e from the error signal e and the signal x ′ (n), and supplies the coefficient w ′ (i) to each multiplier of the filter 7.

[Equation 3]

Accordingly, the characteristic of the filter 7 is D /
Since it is H ′, the output signal y (n) is y (n) = (D / H ′) · x (n). Further, y (n) output from the speaker 11
Is given a transfer characteristic H, the signal h (n) captured by the microphone 12 is as follows: h (n) = H · y (n) = H · (D / H ′) · x (n) Become. If the transfer characteristic H is accurately estimated as described above, then H / H'≈1, and therefore h (n) ≈D · x (n) ≈d (n). Further, in order to bring H / H ′ close to 1, it can be realized by increasing the number of connections of the delay element D, appropriately setting the value of μ, and the like.

Therefore, the musical tone reaching the microphone 12 has a frequency characteristic D corresponding to the genre code JC in the addition result x (n) regardless of the transfer characteristic H due to the external environment.
Will be given. That is, the musical sound heard by the performer has a desired frequency characteristic D.

The following modifications are possible in the above embodiment. Although the above-described embodiment has a monaural structure, it may have a stereo structure with two speakers and two microphones as shown in FIG. 6 (1). In this figure, x
Each of _R (n) and x _L (n) is the addition result x in FIG.
(N) is distributed for R and L channels,
x _R (n) is the filter 7 _RR , 7 _RL , and x _L (n)
Are supplied to the filters 7 _LR and 7 _LL , respectively. The filter 7 _RR gives an inverse characteristic of the transfer characteristic H _RR from the speaker 11R to the microphone 12R. Similarly, the filter 7 _RL has a transfer characteristic H _RL from the speaker 11R to the microphone 12L, and the filter 7 _LR has a transfer characteristic H _RL. The filter 7 _LL of the transfer characteristic H _LR from the speaker 11L to the microphone 12R gives each reverse characteristic of the transfer characteristic H _LL from the speaker 11L to the microphone 12L. And the adder SR
In, the outputs of the filters 7 _RR and 7 _LR are added, and the addition result is sounded from the speaker 12R. Similarly,
The outputs of the filters 7 _LR and 7 _LL are added in the adder SL, and the addition result is sounded from the speaker 12L. When the filters 7 _RR , 7 _RL , 7 _LR and 7 _LL and the transfer characteristics H _RR , H _RL , H _LR and H _LL are configured to correspond to each other as in the above-described embodiment, the musical sound is stereo. be able to.

The frequency characteristics described above correspond to the genre code JC and are fixed, but may be set arbitrarily by the performer. Further, a plurality of items may be set so that a desired item may be selected.

[0030]

As described above, according to the present invention,
The filter means controls the frequency characteristic of the musical tone signal so as to compensate for the frequency characteristic variation due to the indoor environment, so that it is possible to provide an electronic musical instrument in which the musical tone reaching the listener has a desired frequency characteristic. is there.

[Brief description of drawings]

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

FIG. 2 is a schematic block diagram for explaining the operation of the embodiment.

FIG. 3 is a schematic block diagram for explaining the operation of the embodiment.

FIG. 4 is a plan view showing a detailed configuration of an operation panel 2 in the embodiment.

FIG. 5 is a block diagram showing a detailed configuration of a filter 7 in the embodiment.

FIG. 6 is a block diagram showing a main configuration of a modified example of the present invention.

[Explanation of symbols]

3 ... Musical sound signal generating section (musical sound signal generating means), 5 ... Data supplying section (target value supplying means), 6 ... Calculation section (filter controlling means), 7 ... Filter (filtering means), 11
...... Speaker (output means), 12 ... Microphone (input means)

Claims (1)

[Claims] 1. A tone signal generating means for generating a predetermined tone signal, a filter means for filtering the tone signal with a characteristic defined by a filter coefficient, and a tone signal filtered by the filter means. Output means for outputting a musical sound, input means for inputting a musical sound by the output means and converting it into a signal, storage means for storing at least one or more data relating to desired frequency characteristics and selectively supplying the data An electronic musical instrument comprising: a filter control unit that calculates and generates the filter coefficient from the data supplied from the storage unit and the signal from the input unit and supplies the filter coefficient to the filter unit.