JPH08328587A - Acoustic effect device - Google Patents

Abstract

PURPOSE: To provide an acoustic effect device capable of converting an optional interval into an inharmonic interval by adding the multiplication values obtained by multiplying output signals of two phase shifters having a specified phase difference with two output signals of a low frequency oscillator at optional combination. CONSTITUTION: First, second phase shift means 7, 8 having the phase difference of 90 deg. each other are connected in parallel to a band-pass filter 4 through which only a prescribed band of an input signal S2 can be passed. First, second phase shift means output signals S6, S7 respectively outputted from the first, second phase shift means 7, 8 are multiplied respectively with first, second oscillation means output signals S3, S4 respectively outputted from two output terminals with the phases different by 90 deg. from each other of an oscillation means 3 oscillating a frequency smaller than the input signal S2 by an operation means 9 at the prescribed combination. Then, by adding the multiplication values, the optional interval is converted into the inharmonic interval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound effect device, and is suitable for application to, for example, conversion of the pitch of a musical instrument.

[0002]

2. Description of the Related Art Conventionally, as a sound effect device, there is a pitch shifter for converting an echo or a pitch. For example, like a playback device for a back-up orchestra performance without vocals (that is, karaoke), an audio player with a variable speed playback function that allows the tempo, that is, the playback speed to be arbitrarily variable so that the karaoke playback can be performed at the tempo desired by the user. In the signal reproducing device, a pitch converting device is used to perform a pitch converting process so that the pitch of the reproduced audio signal, that is, the pitch, does not change due to the change of the reproducing speed.

[0003]

By the way, when the pitch is converted, the pitch is converted according to the reproduction speed. However, there is a problem that it is difficult for a user to obtain a desired pitch even if the user desires to convert the pitch into a nonharmonic pitch.

The present invention has been made in consideration of the above points, and an object thereof is to propose an acoustic effect device capable of converting an arbitrary pitch into a nonharmonious pitch.

[0005]

In order to solve such a problem, in the present invention, the first and second transfer elements having a phase difference of 90 degrees from each other are provided to a bandpass filter which passes only a predetermined band of an input signal. Phases of the first and second phase shifting means output signals respectively output from the first and second phase shifting means and the oscillating means for oscillating a frequency smaller than the input signal are mutually connected by connecting the phase means in parallel. And a first oscillating means output signal respectively outputted from two output terminals different by 90 degrees from each other by a predetermined combination, and an arithmetic means for adding the multiplied value.

[0006]

The first and second phase difference filters have a phase difference of 90 degrees with each other in the band pass filter that allows only a predetermined band of the input signal to pass.
Of the first and second phase shifting means, which are respectively output from the first and second phase shifting means, and the oscillating means for oscillating a frequency smaller than the input signal. By multiplying the first and second oscillating means output signals respectively output from the two output terminals whose phases are different from each other by 90 degrees in a predetermined combination by the arithmetic means, and adding the multiplied values. , Can convert any pitch into an inharmonic pitch.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a sound effect device 1 of the present invention is shown.
Shows the configuration of. The sound effect device 1 includes an A / D converter 2 for converting an analog signal S1 input from the outside into a digital signal, an oscillator 3 having two output terminals whose phases are different from each other by 90 degrees, three filters 4 to 6, and a band pass filter. It is composed of two phase shifters 7 and 8 connected in parallel to the output terminal of the filter 4 and multipliers 9a and 9b for multiplying two input signals.

The three filters 4 to 6 are band pass filters (hereinafter referred to as BPFs (Band Pass Filters)).
4. Low pass filter (hereinafter LPF)
r)) 5, high-pass filter (hereinafter referred to as HPF (Hi
gh Pass Filter) 6) and divides the digitized input signal S2 into predetermined frequency bands. BPF4 is an audible sound band of 200 [Hz] to 10 [kHz
z] frequency band, LPF5 is 200 [Hz]
It is a filter that passes the following frequency bands. Also,
The HPF 6 is a filter that passes a frequency band of 10 [kHz] or higher.

BPF 4, LPF 5, and HPF 6 are connected in parallel to the output terminal of the A / D converter 2 of the acoustic effect device 1. Further, the phase shifters 7 and 8 are provided at the output end of the BPF 4.
Are connected in parallel, and multipliers 9a and 9b are connected to the phase shifters 7 and 8, respectively. This phase shifter 7 and 8
Have a phase difference of 90 degrees from each other. 50 [Hz]
The low-frequency oscillator 3 that self-oscillates the frequency of has two output terminals 3a and 3b whose phases are different by 90 degrees,
One of the output signals S3 and S4, S3 or S4
Is input to the multiplier 9a, while S4 or S3 is input to the multiplier 9b.
A switch unit 10 for inputting to the input is provided. At this time, the destination of the output signals S3 and S4 from the oscillator 3 is controlled by the control unit 11.

The multipliers 9a and 9b are connected to the adder 12, and are connected to the integrator 14 via the HPF 13 of DC (Direct Current) cut. This integrator 14 is
The C-cut HPF 13, LPF 5, and HPF 6 are connected in parallel, and the operation result signal S 5 is transferred to the D / A converter 1
It is designed to output via the 5.

In the above configuration, when the input signal S1 from the outside is transmitted to the acoustic effect device 1, the input signal S1 is converted into the digital signal S2 by the A / D converter 2 and converted into BPF4, LPF5, HPF6. Sent. The digital signal S2 passes the frequency band of 200 [Hz] or less by the LPF 5, passes the frequency band of 10 [kHz] or more by the HPF 6, and is output to the integrator 14, respectively. The digital signal S2 passes through the BPF 4 only in the frequency band of 200 [Hz] to 10 [kHz], which is an audible sound band, and is output to the phase shifters 7 and 8, respectively.

Output signals S6 and S7 from the two phase shifters 7 and 8 having a phase difference of 90 degrees with each other are transmitted to multipliers 9a and 9b, respectively. Further, the two output signals 3a and 3b obtained by the oscillator 3 are transmitted to the multiplier 9a by the control signal from the control unit 11 which is sent to the switch unit 10. , The other 3b or 3a is transmitted to the multiplier 9b. At this time, each of the two signals input to each of the multipliers 9 a and 9 b is multiplied and output to the adder 12, respectively. The output signal S8 from the adder 12 is transmitted to the integrator 14 via the HPF 13. The integrator 14 has a HPF 13,
The signals input from the LPF 5 and the HPF 6 are calculated, and the signal S5 of the calculation result is output as an analog signal via the D / A converter 15.

Here, a concrete example of conversion of frequency components will be described. The two phase shifters 7 and 8 have a phase difference of 90 degrees with each other. Therefore, the input signal S1 from the outside is
If in (ω _in t), the output signal S6 of the phase shifter 7 can be expressed as sin (ω _in t + p) due to the phase shift by the phase shifter. Further, the output signal S7 of the phase shifter 8 is
It can be represented by cos (ω _in t + p) with a phase difference of degrees. At this time, if the two output signals S3 and S4 of the low frequency oscillator 3 are sin (ω _L t), cos (ω _L t), respectively, when down, the output signal S8 from the adder 12 is

[Equation 1] And is converted into a frequency lower by the angular frequency ω _L of the low frequency oscillator 3.

If the same condition is met, the adder 12
The output signal S8 from

[Equation 2] And is converted into a frequency higher by the angular frequency ω _L of the low frequency oscillator 3. Incidentally, this up / down is determined by controlling the switch unit 10 arranged at the output end of the oscillator 3 by the control unit 11.

Specific examples of frequency components shifted by up / down at this time are shown in FIGS. 2 (A) to 2 (C). 2A shows the frequency components of the input signal S1, and FIGS. 2B and 2C show the frequency components after shifting due to down and up. First, the frequency component of the input signal S1
200 [Hz], 300 [Hz] ... 600 [Hz] (Fig. 2
(A)). Here, when the frequency of the input signal S1 is set to a frequency lower than 60 [Hz], the frequency component of the output signal S8 is as shown in FIG.
As shown in (B), 140 [Hz], 240 [Hz] ... 540
It becomes [Hz]. Here, usually, the harmony of the pitch is established by the harmonic relationship, but the frequency component after frequency down is obtained by subtracting 60 [Hz] from each frequency component before down, so the harmonic relationship is Can be said to have collapsed.

Similarly, the frequency of the input signal S1 is set to 100 [H
z] When the frequency is high, the frequency components of the output signal S8 are 300 [Hz] and 400 [Hz] as shown in FIG.
...... It becomes 600 [Hz]. In this case as well, the frequency component after frequency up is obtained by adding 100 [Hz] to each frequency component before up, so it can be said that the harmonic relationship for maintaining the harmony of the pitch is broken. Therefore, the sound effect device 1 of the present invention
Thus, the pitch of the input signal S1 can be converted into a nonharmonic pitch by converting the pitch in the audible sound band.

According to the above configuration, the band pass filter 4
Audible sound band (200 [Hz] to 10 [kHz]
z]) only the signal component is extracted, and phase shifters 7 and 8 having a phase difference of 90 degrees from each other in the pass band.
Of the low frequency oscillator 3 and an output signal of the low frequency oscillator 3 multiplied by an arbitrary combination are added to convert the frequency component in the form of a sum difference, so that the pitch of the input signal S1 is It can be converted into a harmonious pitch.

In the above embodiment, the analog signal S1 input from the outside is digitally converted by the A / D converter 2 and then transmitted to the band filters 4 to 6, but the present invention is not limited to this. Not limited to this, a digital signal from an external digital sound signal input means or the like may be directly transmitted to the band filter.

In the above embodiment, the low frequency oscillator 3 which self-oscillates at a frequency of 50 [Hz] is used. However, the present invention is not limited to this, and a frequency oscillator other than 50 [Hz] can be used. good. The oscillator at this time is not limited to a self-oscillating oscillator, but may be an oscillator controlled by hardware.

Further, in the above-mentioned embodiment, the acoustic effect device 1 in which the HPF 13 for DC cutting is connected to the output end of the adder 12 has been described, but the present invention is not limited to this, and the HPF 13 is excluded. It may be a sound effect device.

Further, in the above-mentioned embodiment, the one used for the conversion of the pitch of the musical instrument has been described, but the present invention is not limited to this and can be applied to the conversion of the pitch other than the musical instrument.

[0023]

As described above, according to the present invention, first and second phase shifting means having a phase difference of 90 degrees from each other are connected in parallel to a band pass filter which passes only a predetermined band of an input signal. However, the first and second phase means output signals respectively output from the first and second phase shift means and the oscillating means for oscillating a frequency smaller than the input signal have a mutual phase of 90 degrees.
The first and second oscillating means output signals respectively output from two different output terminals are multiplied by a predetermined combination by the calculating means, and the multiplication values are added to obtain an arbitrary pitch. It is possible to realize a sound effect device that can convert the sound into an inharmonic pitch.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram showing frequency examples before and after shifting by the acoustic effect device of the present invention.

[Explanation of symbols]

1 ... Sound effect device, 2 ... A / D converter, 3 ...
Oscillator, 4 ... BPS, 5 ... LPF, 6,13 ... H
PF, 7, 8 ... Phase shifter, 9a, 9b ... Multiplier, 10
...... Switch section, 11 ...... Control section, 12 ...... Adder, 1
4 ... integrator, 15 ... D / A converter.

Claims (3)

[Claims] 1. An oscillating means for arranging two output terminals whose phases are different from each other by 90 degrees and oscillating a frequency smaller than an input signal, and a first and a first means which are connected in parallel and have a phase difference of 90 degrees from each other. Second phase shifting means, first and second phase shifting means output signals respectively output from the first and second phase shifting means, and first output points respectively from two output ends of the oscillating means. And a calculation means for multiplying the output signals of the second oscillating means by a predetermined combination and adding the multiplied values, respectively. 2. A bandpass filter for passing only a predetermined band of an input signal, first and second phase shift means connected in parallel to the bandpass filter and having a phase difference of 90 degrees with each other, and Oscillation means for arranging two output terminals having phases different by 90 degrees and oscillating a frequency smaller than the input signal, and first and second phase shifts output from the first and second phase shift means, respectively. And means for multiplying the means output signal and the first and second oscillating means output signals respectively output from the two output terminals of the oscillating means by a predetermined combination, and adding the multiplied values. A sound effect device. 3. The sound effect device according to claim 2, wherein the band pass filter passes only an audible sound band.