JPH07199920A - Electronic keyed instrument - Google Patents

Abstract

PURPOSE:To provide the device capable of enhancing the low-pitched sound reproducing acoustic pressure without damaging a sense of movement of orientation of an acoustic image due to the key touching position. CONSTITUTION:Left and right independent sound source signals (a) and (b) are mixed by a mixer 6 and are filtered by a low pass filter 7 which allows only the sound source signal having the low-pitched sound reproducing limit frequencies or lower of speakers to pass through, and signals (e) equally divided as signals of two systems are generated by a divider 9. Meanwhile, sound source signals (a) and (b) branched in the preceding stage of the mixer 6 are filtered by high-pass filters 8a and 8b to obtain signals (f) and (g) having frequencies higher than low-pitched sound reproducing limit frequencies, and these signals are mixed with signals having frequencies lower than low-pitched sound reproducing limit frequencies from the divider 9 by remixers 10a and 10b to obtain signals (h) and (i). Signals (h) and (i) are amplified by a stereo amplifier 3 and are emitted as sounds from speakers 4a and 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic keyboard instrument having an increased bass reproduction sound pressure.

[0002]

2. Description of the Related Art In recent years, electronic keyboard musical instruments, like acoustic keyboard musical instruments, have a left and right independent (hereinafter referred to as stereo) sound source signal in order to produce a sound from the vicinity of a depressed key. Stereo amplifier is abbreviated), and the method of playing with speakers placed on the left and right ends of the main body is increasing.

An example of a conventional electronic piano will be described below with reference to FIGS. 2, 3 and 4. FIG. 2 is a partial sectional view showing the structure of a conventional electronic piano. In FIG. 2, 1 is a keyboard, 2 is a sound source containing a stereo music signal, 3 is a stereo amplifier, 4a and 4b are speakers, and 5 is a control microcomputer.

The operation of the electronic piano constructed as above will be described below. First, when one of the keys on the keyboard 1 is pressed, the information is input to the microcomputer 5, and the microcomputer 5 extracts the stereo sound source signal corresponding to the keystroke position from the sound source and sends it to the stereo amplifier 3. The sound source signal amplified by the amplifier is sent to the speakers 4a and 4b and is sounded.
FIG. 3 is a signal block diagram and a signal waveform diagram of a conventional electronic piano. For the sound source, a signal for each scale from the left-most low-pitched key to the right-most trebled key, and the sound image is localized on the left for low-pitched keys, in the center for mid-tone keys, and on the right for high-tone keys. Thus, the left and right signal levels are set. In the figure,
Symbols a and b are signal waveform diagrams showing the waveforms of the sound source signals flowing in the circuit when a low-pitched key is pressed, where a is a left signal and b is a right signal. The vertical axis of the signal waveform diagram represents the amplitude, and the horizontal axis represents the time. A waveform having a large amplitude and time represents a low tone, and a waveform having a small amplitude and time represents a high tone. FIG. 4 is a reproduction sound pressure frequency characteristic diagram and an impedance characteristic diagram of the speaker. The vertical axis represents the sound pressure emitted from the speaker, and the horizontal axis represents the frequency input to the speaker. In the figure, fo is the bass reproduction limit frequency of the speaker,
A frequency lower than this indicates a frequency at which the reproducible sound pressure sharply decreases. Generally, the electronic piano uses a speaker having a small diameter so as to make the speakers 4a and 4b, which are not present in the acoustic piano, conspicuous in order to approximate the form of the acoustic piano.

[0005]

However, in the above-mentioned conventional configuration, since the signal level on the left side is high at the time of low-pitched keying on the left end, the power load on the amplifier and the speaker on the left side is large, and the bass sound is generated on the small-diameter speaker. Since the reproduction limit frequency is high, there is a problem that the volume of low sounds is insufficient.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an electronic keyboard instrument having an increased bass reproduction sound pressure.

[0007]

In order to achieve this object, the electronic keyboard musical instrument of the present invention separates a sound source signal below the bass reproduction limit frequency of a speaker from two left and right system signals, and after mixing, It has a configuration in which a circuit for uniformly returning to a system signal is provided.

[0008]

With this configuration, the bass signal is amplified by the two systems of stereo amplifiers and reproduced by the two speakers, so that the bass reproduction sound pressure can be increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a signal block and signal waveform diagram of an electronic keyboard instrument according to a first embodiment of the present invention. In FIG. 1, 6 is a mixer that mixes left and right signals, 7 is a low-pass filter that allows only signals having a frequency below the bass reproduction limit (hereinafter abbreviated as fo) of the speaker to pass, and 8
a and 8b are high-pass filters that pass only signals of frequency fo or higher, 9 is a divider that evenly divides signals of two systems, 1
Reference numerals 0a and 10b denote remixers for mixing the signal from the divider 9 and the signals from the high pass filters 8a and 8b.

The operation of the electronic piano configured as described above will be described with reference to the signal waveform chart of each branch point when a low-pitched key is pressed. The signals a and b that have entered the mixer 6 are added together and become c, which is filtered by the low-pass filter 7 into only signals having a frequency lower than the fo frequency and becomes d, and the signal is evenly divided by the divider 9 to become e. On the other hand, the signals a and b branched in the preceding stage of the mixer 6 are filtered by the high-pass filters 8a and 8b into only signals having a frequency higher than the fo frequency to become f and g, and the signals from the divider 9 from the divider 9 are remixed by the remixers 10a and 10b. It is mixed with a signal having a frequency lower than the frequency, resulting in h and i. h and i are amplified by the stereo amplifier 3 and sounded as sounds from the speakers 4a and 4b.

As described above, since the signals of the fo frequency or lower are shared and amplified by the two systems of amplifiers, the utilization efficiency of the amplifiers is increased, and the sound is reproduced by two speakers, so that the reproduction sound pressure of the low frequency is increased. You can It is generally known that low frequency sounds have no sense of localization. The sound source signal at the time of low-pitched key typing has a large left-side signal so that the sound image is localized to the left, but localization is determined by sounds above the fo frequency, and localization below the fo frequency gives a sense of localization. Because there is no
Even if reproduced from the speakers at both ends, the sound image is not centered.

As described above, according to this embodiment, two independent sound source signals and a sound source signal having a bass reproduction limit frequency of the speaker or less are separated from the two sound source signals and mixed, and then two sound source signals are mixed. By providing a circuit for uniformly returning to the signal of, the electronic keyboard musical instrument with high bass reproduction sound pressure can be constructed.

In the embodiment, the two-system mixed signal equally divided by the divider 8 is mixed with the original signal. However, a higher effect can be obtained by amplifying the mixed signal and then mixing it with the original signal. It goes without saying that you can get it.

[0014]

As described above, according to the present invention, two independent sound source signals and a sound source signal having a bass reproduction limit frequency of a speaker or less are separated from the two sound source signals and mixed,
By providing a circuit that returns signals to two systems evenly, it is possible to realize an excellent electronic keyboard instrument capable of increasing the bass reproduction sound pressure without impairing the sense of localization of the sound image depending on the keystroke position.

[Brief description of drawings]

FIG. 1 is a signal block and signal waveform diagram of an electronic keyboard instrument according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing the structure of a conventional electronic piano.

FIG. 3 is a signal block diagram and signal waveform diagram of a conventional electronic piano.

[Fig. 4] Playback sound pressure frequency characteristic diagram and impedance characteristic diagram

[Explanation of symbols]

 1 keyboard 2 sound source 3 stereo amplifier 4a, 4b speaker 5 microcomputer 6 mixer 7 low-pass filter 8a, 8b high-pass filter 9 divider 10a, 10b remixer

Claims (1)

[Claims] 1. A circuit for separating left and right independent two-system sound source signals and a sound source signal below a bass reproduction limit frequency of a speaker from the two-system sound source signals, mixing them, and then uniformly returning to the two-system signals. An electronic keyboard instrument that is characterized by