JPH08237056A - Amplitude/phase adjustment device - Google Patents

Abstract

PURPOSE: To correct the amplitude and phase characteristic of a speaker by adding a phase adjustment circuit and a level adjustment device to each of plural band pass filters being components of the band characteristic adjustment device so as to adjust both the amplitude and the phase. CONSTITUTION: The device is provided with a 1st band control circuit 21 consisting of a band pass filter 1, a phase adjustment circuit 3 shifting a phase of a signal passing through the band pass filter 1, and a level adjustment device 5 adjusting the output level of the phase adjustment circuit 3, with 2nd, 3rd,..., n-th band control circuits 22, 23,..., 29 each comprising a band pass filter, a phase adjustment circuit and a level adjustment device similarly to the case with the 1st band control circuit 21, and a 1st adder circuit 7 summing outputs of the circuits 21, 22, 23,...29 to provide the amplitude wave form and the phase wave form characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplitude / phase adjusting device capable of correcting amplitude and phase characteristics with respect to frequencies in an arbitrary frequency band.

[0002]

2. Description of the Related Art In a system in which sound waves of opposite phase are radiated from a speaker and noise or sound output from the speaker is controlled by utilizing the interference effect of the sound waves, a sound wave of opposite phase output from a control device is used. , The transfer characteristics such as amplitude and phase rotation are complicatedly affected by electrical, mechanical and acoustic elements unique to each system. When noise or a sound wave output from a speaker is viewed as a positive-phase sound wave, a negative-phase sound wave output from a negative-phase speaker is a positive-phase sound wave whose amplitude or phase transfer characteristics are controlled at an interference point. , Outputs with amplitudes that cancel each other out and must be controlled so that they are synchronized exactly in anti-phase relation, and the system cannot work effectively.

A graphic equalizer has been conventionally known as a typical device for controlling the characteristics of the sound output from a speaker. This uses a large number of band pass filters that can pass only the necessary frequency components, and divides a wide frequency band into small parts,
It is intended to finely control a wide frequency band by independently adjusting the magnitude of the pass band amplitude of each band pass filter.

[0004]

[Problems to be Solved by the Invention]
The equalizer is used for the purpose of correcting the amplitude characteristic with respect to the frequency, and cannot correct the phase characteristic. The phase characteristics of the graphic equalizer, which has been adjusted so that the amplitude characteristics of all bands are flat, show that the input and output signals are in phase at the center frequency with the frequency at the center of the entire band as the boundary, and are lower than the center frequency. Then, as the frequency becomes lower, the phase of the output signal with respect to the input signal gradually advances, and in the band higher than the central frequency, as the frequency becomes higher, the phase of the output signal with respect to the input signal gradually delays. Also, the steeper the attenuation characteristic near the center frequency of each band pass filter, the greater the proportion of the slope of the phase lead and the phase lag with the center frequency as the boundary. Further, if the amplitude characteristic of an arbitrary band pass filter is changed, there arises a problem that the amplitude characteristic and the phase characteristic of other band pass filters are influenced and changed. Therefore, the traditional graphic equalizer
In particular, since there is no degree of freedom regarding the phase characteristics, it cannot be used as a device for adjusting the amplitude and phase characteristics.

In view of the above-mentioned problems, the problem to be solved by the present invention is to add a phase adjusting circuit and a level adjuster to each of a plurality of band pass filters constituting a band characteristic adjusting device, and to adjust the amplitude and the phase. It is an object of the present invention to provide an amplitude / phase adjusting device capable of correcting the amplitude and phase characteristics of the speaker by enabling both adjustments.

[0006]

An amplitude / phase adjusting device according to the present invention solves the above problems and is as follows. That is, in a band characteristic adjusting device that controls the amplitude and phase of a signal that passes through an arbitrary frequency band, a band pass filter 1 having a center frequency corresponding to a shared pass band, and the band pass filter 1 are provided. Phase adjustment circuit 3 for shifting the phase of a passing signal
And a level adjuster 5 for adjusting the level of the output of the phase adjusting circuit 3, and a band pass filter, a phase adjusting circuit, and a level similar to the first band controlling circuit 21. A second, third, ...
.., 29 and the first adder circuit 7 for adding the outputs of the nth band control circuits 22, 23, ... It has characteristics.

A band control circuit in which the shared pass band is divided into arbitrary octave intervals. Second amplitude / phase adjustment circuit 1 in which the range control circuit is grouped
1 and a second adder circuit 7A for adding the output of the first amplitude / phase adjusting circuit 10 and the output of the second amplitude / phase adjusting circuit 11 to each other. Wavy characteristic of amplitude and wavy characteristic of amplitude of the second amplitude / phase adjusting circuit 11, and wavy characteristic of phase of the first amplitude / phase adjusting circuit 10 and wavy characteristic of phase of the second amplitude / phase adjusting circuit 11. And are averaged respectively.

Further, the first amplitude / phase adjusting circuit 10 described above.
And a second amplitude / phase adjusting circuit 11 are added to a third amplitude / phase adjusting circuit 12, a phase advancing circuit 13 in which the advance of phase increases with an increase in frequency, and a phase deviation due to a change in frequency. The phase distortion with respect to the frequency is corrected by adding the third phase adjusting circuit 14 which does not change the magnitude of the shift.

[0009]

[Function] An arbitrary two adjacent band pass filters are selected from a plurality of band pass filters for dividing an arbitrary frequency band by an octave band, and the one having the lower center frequency is the first band pass filter 1 or the center frequency. The higher one is the second band pass filter 2, and the first and second band pass filters 1 and 2 are provided with the first and second phase adjusting circuits 3 and 4 capable of adjusting the lead phase or the lag phase, respectively. And the first and second level adjusters 5 and 6 capable of adjusting the amplitude level are added,
First and second band pass filter 1 When the first and second phase adjusting circuits 3 and 4 and the first and second level adjusters 5 and 6 are adjusted so as to have an inflection point that changes to a negative value, the amplitude characteristic and the phase characteristic are given wavy characteristics, respectively. To be With respect to the other band pass filters having the side-by-side relationship, by adjusting the respective parts in the same manner as the first and second band pass filters 1 and 2, the center frequency of each band pass filter is adjusted. An output signal having a required amplitude and little phase distortion between the input and output signals can be obtained.

Further, the first and second amplitude / phase adjusting circuits are arranged by arranging a plurality of band control circuits in which the intervals of the center frequencies are set to arbitrary octave intervals in order from the lowest frequency and by alternately allocating the band control circuits into two groups. Amplitude wave characteristics and phase wave characteristics of the first and second amplitude / phase adjusting circuits 10 and 11 by configuring outputs 10 and 11 and adding outputs of the first and second amplitude / phase adjusting circuits 10 and 11 respectively. Can be averaged respectively.

The first amplitude / phase adjusting circuit 10 and the second
The phase characteristic of the averaged output obtained by adding the amplitude / phase adjusting circuit 11 is the change in frequency and the attenuation characteristic in the vicinity of the center frequency of each band control circuit constituting the third amplitude / phase adjusting circuit 12 and , Phase shifts having different characteristics occur depending on the magnitude of the influence exerted by other band control circuits. According to the slope of this phase shift characteristic,
Phase advance circuit 13 in which the phase advance increases with increasing frequency
And the third phase adjusting circuit 14 in which the magnitude of the phase shift does not change due to the change in the frequency, and by correcting the slope of the phase shift characteristic and the phase shift characteristic, distortion due to the phase shift is caused. Can be corrected.

[0012]

Embodiment 1 An amplitude / phase adjusting device of the present invention will be described with reference to FIGS. 1 and 5. FIG. 1 is a block diagram of an amplitude / phase adjuster according to the present invention, FIG. 5 (A) is a waveform diagram showing amplitude wavy characteristics, and FIG. 5 (B) is a waveform diagram showing phase wavy characteristics. In FIG. 1, 1 and 2 are first and second band pass filters, 3 and 4 are first and second phase adjustment circuits, and 5 and 6 are first and second level adjusters, 7
Is a first adder circuit, 8 is an input terminal, 9 is an output terminal,
The portions 21 to 29 surrounded by the dotted line form the first to nth band control circuits. The operation of FIG. 1 will be described below.

First to n-th band control circuits 21 to 21 which are arranged in order from the lowest center frequency and are formed by dividing an arbitrary frequency band into n.
29 is connected to the input terminal 8. First and second
The outputs of the band pass filters 1 and 2 are first and second phase adjusting circuits 3 capable of adjusting the phase to be arbitrarily advanced or delayed without changing the magnitude of the phase shift due to the frequency change. 4 is connected. The outputs of the first and second phase adjusting circuits 3 and 4 are adjusted in level by the first and second level adjusting circuits 5 and 6 and output. First
Band pass filter 1, first phase adjustment circuit 3, first
The level adjuster 5 constitutes the first band control circuit 21, the second band pass filter 2, the second phase adjuster circuit 4, and the second level adjuster 6 constitute the second band control circuit 22. And the outputs of the second band control circuits 21 and 22 are the third, fourth, and fourth band-pass filters, the phase adjustment circuit, and the level adjuster, which are similar to the first and second band control circuits 21 and 22. ..., the n-th band control circuit 23, 2
, ..., 29 and the outputs of the first addition circuit 7 are added together, and the output of the first addition circuit 7 is connected to the output terminal 9.

From the wide band signal input to the signal input terminal 8, the first to nth band control circuits 21 to 29
Only the frequency components required by the respective band control circuits are allowed to pass, and the signals whose phase shifts and amplitude levels have been adjusted of the respective band pass signals are added and synthesized by the first adding circuit 7 to obtain an arbitrary frequency band. The amplitude and phase of
It outputs from the output terminal 9 as a signal adjusted independently, respectively.

The transfer function of the amplitude / phase adjusting device of the present invention is F, and the first to nth band control circuits 21 to 2 forming F are formed.
If the transfer functions of 9 are F _{1 to} F _n , respectively, the signal input to the input terminal 8 and output from the signal output terminal 9 is
Passes through the first band control circuit 21 The amplitude magnitude and phase deviation angle of the signal passing through the nth band control circuits 22 to 29 are faxed. It can be expressed as.

[0016] Crossover between adjacent band control circuits of the nth band control circuits 21 to 29 Add a vector to each band control circuit as a factor,
Each band control circuit The magnitude of the frequency deviation generated between the maximum frequency and α _{1 to} α _n is Adjust each part so that Further, between the adjacent band control circuits, which are adjacent to each other, similarly to the case between the first and second band control circuits 21 and 22, it is possible to obtain an output signal having wavy characteristics in amplitude and phase by sequentially performing the adjustment. it can.

A signal having a flat amplitude characteristic is applied to the amplitude / phase adjusting device of the present invention set as described above. Assuming that the amplitude and phase changes with the frequency as a parameter between the two band control circuits, the frequency is swept along the axis of ordinate and the phase shift on the axis of abscissa indicating the left side of the phase shift and the right side of the phase shift. , Rotate right while increasing the frequency while making a small rotation

As described above, in the amplitude / phase adjusting device of the present invention, the amplitude becomes maximum in the vicinity of each center frequency of a plurality of band control circuits provided in an arbitrary band,
By adjusting so that a signal whose phase deviation becomes an inflection point at the center frequency is obtained, amplitude and phase characteristics are given to the amplitude and phase, respectively. It is possible to reduce the influence given as a vector in the vicinity of the center frequency of the control circuit and to add a certain limit to the magnitude of the phase shift.

Second Embodiment A second embodiment according to the present invention will be described with reference to FIG. Figure 2
6A is a block diagram of an amplitude / phase adjusting device formed by combining two sets of amplitude / phase adjusting circuits in which the amplitude wavelike characteristic and the phase wavelike characteristic complement each other. FIG. 6A shows the first amplitude / phase adjusting circuit 10. Of the second amplitude / phase adjusting circuit 11 (dotted line), and FIG. 6B shows the third amplitude / phase adjusting circuit 12.
6C is a waveform diagram showing the phase wavy characteristic of the first amplitude / phase adjusting circuit 10 (solid line) and a waveform diagram showing the phase wavy characteristic of the second amplitude / phase adjusting circuit 11 ( FIG. 6D is a waveform diagram showing the phase shift of the third amplitude / phase adjusting circuit 12 (dotted line). The same parts as those in FIG. 1 are designated by the same reference numerals. In FIG. 2, 7A and 7B, 7C
Are second, third and fourth adder circuits, and 10 and 11, 12 are first, second and third amplitude / phase adjusting circuits. The operation of FIG. 2 will be described below.

[0020] The frequency bands are divided in such a manner that the respective passbands are equally octave-spaced, and the second, third, and fourth adder circuits 7A, 7B, and 7C are
The first adder circuit 7 is configured. First to eighth band control circuit 2
1 to 28 are assigned to the first, third, fifth and seventh band control circuits 21, 2
3, 25, 27 and second, fourth, sixth, eighth band control circuit 2
Alternately divided into 2, 24, 26, and 28 to form two sets of groups, and the groups are added by the third adder circuit 7B and the fourth adder circuit 7C, respectively, and the first amplitude / phase adjustment circuit 10 and the second The amplitude / phase adjusting circuit 11 is configured, and the output of the first amplitude / phase adjusting circuit 10 and the output of the second amplitude / phase adjusting circuit 11 are connected to the second adding circuit 7A.
The third amplitude / phase adjusting circuit 12 is configured by adding

Here, the attenuation characteristics near the center frequency of the band control circuits 21 to 28 forming the first and second amplitude / phase adjusting circuits 10 and 11 and the first to eighth band control circuits 2 are described.
The interval of division by the octave band, which is the pass band shared by 1 to 28, is appropriately determined, and the first and second amplitude
The amplitude wavy characteristics (FIG. 6A) and the phase wavy characteristics (FIG. 6) of the corresponding frequency bands of the phase adjustment circuits 10 and 11 are shown.
(C)) so that the relationship with
And the outputs of the second amplitude / phase adjusting circuits 10 and 11 to the second
When added by the adder circuit 7A, the added output is vector-combined and averaged to obtain the output of the first adder circuit 7 (see FIG. 6).
(B) and (C), which are output as signals having stable amplitude and phase characteristics with little amplitude variation with respect to frequency and little phase deviation variation.

Third Embodiment A third embodiment will be described with reference to FIG. FIG. 3 is a block diagram of a circuit for correcting the slope of the phase shift characteristic and the phase shift of the amplitude / phase adjusting device according to the present invention by the phase correction circuit. FIG. 7A shows the correction of the slope of the phase shift. FIG. 7B is a waveform diagram showing the correction of the phase shift. The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals.
In FIG. 3, 13 is a phase advancing circuit, 14 is a third phase adjusting circuit, and a portion 15 surrounded by a dotted line indicates a phase correction circuit. The phase advancing circuit 13 in which the advance of the phase increases with the increase of the frequency is connected to the third phase adjusting circuit 14 in which the magnitude of the phase deviation does not change due to the change of the frequency, and the phase advancing circuit 13 and the third phase adjusting circuit 13 are connected. The phase adjusting circuit 14 constitutes a first phase correcting circuit 15, and the first phase correcting circuit 15 is inserted between the input terminal 8 and the third amplitude / phase adjusting circuit 12.

The frequency showing the maximum value of the amplitude in each band control circuit of the third amplitude / phase adjusting circuit 12 is the third amplitude / phase adjusting circuit 12.
Depending on the factor of the entire system by the phase adjusting circuit 12, there are slight deviations from the center frequency of each band control circuit to α _{1 to} α _n , respectively. The phase deviation corresponding to this minute deviation is θ.
When _{α1 ~θ αn, α 1 ~α n} and through? _{[alpha] 1} through?
_αn has the frequency at the low frequency side as the frequency becomes lower, the frequency becomes lower, the phase advances, and at the high frequency side, the frequency becomes higher as the frequency increases, with the central frequency of the entire system as the boundary. The phase shifts in the direction of delaying, and the magnitude of the shift is such that the shift directions of the low frequency side and the high frequency side are opposite to each other with the center frequency as the boundary. Have an equal relationship.

[0024] It is shown that the phase delay increases as the frequency increases. Where the frequency increase It is corrected so that the magnitude of the phase shift does not change even if the number changes (see FIG. Therefore, the third phase adjusting circuit 14 that does not change the magnitude of the phase shift due to the change in frequency delays the phase of the entire system by θ (FIG. 7B). It is possible to obtain a signal having a characteristic that the phase distortion is small with respect to the frequency change.

Fourth Embodiment A fourth embodiment will be described with reference to FIG. FIG. 4 is a block diagram of a circuit for subdividing and correcting the range of phase correction of the amplitude / phase adjusting device according to the present invention. The same parts as those in FIGS. 1, 2 and 3 are designated by the same reference numerals. . Hereinafter, FIG. 4 will be described. 16 is a second phase correction circuit, 17 and 1
Reference numerals 8 and 19 denote low, middle, and high band control circuit groups formed by dividing an arbitrary band into three groups for low, middle, and high bands. Amplitude / phase adjuster circuit when the phase shift slope in the central midrange is relatively small compared to the low range and high range, and the proportion of the phase shift slope is different from that in the low range and high range. This is an example, and the same correction as in the third embodiment is performed only for the low-frequency control circuit group 17 and the high-frequency control circuit group 19 to eliminate the variation in the magnitude of the phase shift between the bands. It is possible to obtain a signal having a characteristic that the phase distortion is small with respect to the frequency change.

[0026]

According to the present invention, a plurality of band pass
By adding a phase adjustment circuit and a level adjuster to each filter and giving amplitude wavy characteristics and phase wavy characteristics, it is possible to obtain an amplitude / phase adjusting device capable of adjusting both amplitude and phase, and It is possible to obtain an amplitude / phase adjusting device having stable amplitude and phase characteristics with little variation in amplitude and phase with respect to frequency by combining two sets of amplitude / phase adjusting circuits having mutually complementary phase wave characteristics. Further, if the phase is corrected by the phase advancing circuit 13 in which the phase advance becomes large as the frequency increases and the third phase adjusting circuit 14 in which the magnitude of the phase shift does not change due to the frequency change, the entire system is It is possible to obtain an amplitude / phase adjusting device with little phase distortion to the extent that phase delay is not a problem in practical use. Therefore, when the amplitude / phase adjusting device of the present invention is used, it is possible to finely adjust the amplitude and the phase of each band control circuit, which does not require an enormous amount of time and labor for the adjusting work.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an amplitude / phase adjusting device of the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment.

FIG. 3 is a block diagram showing a configuration of a third embodiment.

FIG. 4 is a block diagram showing a configuration of a fourth embodiment.

FIG. 5A is a waveform diagram showing amplitude wavy characteristics. FIG. 7B is a waveform diagram showing a phase wave characteristic.

FIG. 6A is a waveform diagram showing amplitude wavy characteristics of the first and second amplitude / phase adjusting circuits. FIG. 7B is a waveform diagram showing the output of the third amplitude / phase adjustment circuit. FIG. 6C is a waveform diagram showing the phase wavy characteristics of the first and second amplitude / phase adjusting circuits. (D) A waveform diagram showing the phase shift of the third amplitude / phase adjustment circuit.

FIG. 7A is a waveform diagram showing correction of the slope of the phase shift. FIG. 6B is a waveform diagram showing the correction of the phase shift.

[Explanation of symbols]

1, 2 1st, 2nd band pass filter 3, 4, 14 1st, 2nd, 3rd phase adjustment circuit 5, 6 1st, 2nd level adjuster 7 1st addition circuit 7A, 7B, 7C 2nd, 3rd, 4th addition circuit 8 Input terminal 9 Output terminal 10, 11, 12 1st, 2nd, 3rd amplitude / phase adjustment circuit 13 Phase advance circuit 15, 16 1st, 2nd phase correction circuit 17 Low band control circuit group 18 Middle band control circuit group 19 High band control circuit group 21-29 1st to n-th band control circuit

Claims (3)

[Claims] 1. In a band characteristic adjusting device for controlling the amplitude and phase of a signal passing through an arbitrary frequency band, a band pass filter (1) having a center frequency corresponding to a shared pass band, and the band pass filter (1). Pass filter (1)
Adjustment circuit (3) that shifts the phase of the signal that passes through
And a level adjuster (5) for adjusting the level of the output of the phase adjusting circuit (3), a first band control circuit (21)
, And the second, third, ..., Nth band control circuit (22), which is composed of a band pass filter, a phase adjustment circuit, and a level adjuster like the first band control circuit (21).
(23), ..., (29) and a first adding circuit (7) for adding the outputs, and the amplitude characteristic and the phase characteristic with respect to the frequency have an amplitude wavy characteristic and a phase wavy characteristic, respectively. Amplitude / phase adjustment device characterized by. 2. A band formed by dividing a shared pass band into octave intervals. .. a second amplitude / phase adjusting circuit (11) having a band control circuit as a group, the output of the first amplitude / phase adjusting circuit (10) and the second amplitude / phase adjusting circuit (1)
1) and a second adder circuit (7A) for adding the output of the first amplitude / phase adjusting circuit (10) and the amplitude of the second amplitude / phase adjusting circuit (11). And the wavy characteristic of the phase of the first amplitude / phase adjusting circuit (10) and the wavy characteristic of the phase of the second amplitude / phase adjusting circuit (11) are averaged. The amplitude / phase adjusting device according to item 1. 3. A third amplitude / phase adjustment circuit (12) formed by adding the first amplitude / phase adjustment circuit (10) and the second amplitude / phase adjustment circuit (11) to increase the frequency. With the addition of a phase advancing circuit (13) that leads to a large phase advance and a third phase adjusting circuit (14) that does not cause a change in the phase deviation due to a change in frequency, The amplitude / phase adjusting device according to claim 1 or 2, wherein distortion is corrected.