JPS6238340Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a graphic equalizer that can automatically perform compensation operations according to the acoustic characteristics of a reproduction system including a sound field.

Generally, a graphic equalizer is used to compensate for the characteristics of a sound reproduction device such as audio equipment, including the sound field used. Conventionally, when using such a device, it has been difficult to accurately grasp the transmission frequency characteristics of the reproduction system, so for example, music has been reproduced and a graphic equalizer has been operated to a position that seems to have flat characteristics.
However, in such cases, since the system relies on the user's sense of hearing, objective evidence is lacking, and it is extremely difficult to perform accurate compensation.

In some cases, the transmission characteristics of the reproduction system are measured using a pink noise generator, spectrum analyzer, band filter, level meter, etc., and a graphic equalizer is operated based on the results to perform compensation. However, such a method requires a large number of expensive equipment and requires a large number of measurement operations, so it is not common.

Therefore, the first system that can automatically perform compensation operations according to the acoustic characteristics of the reproduction system including the sound field.
A graphical equalizer as shown in the figure has been considered. In the figure, 1 is a line input terminal, 2 is a microphone input terminal, and one of these terminals is switched off and selected by a first switch 3, and is inputted to an equalizer amplifier 4. Then, the output of the equalizer amplifier 4 is outputted to the output terminal 6 via the second switch 5. Note that this output terminal 6 is connected to, for example, an input terminal of an output amplifier (not shown). Also the second
The switch 5 selects either the output of the equalizer amplifier 4 or the pink noise generated by the pink noise generator 7. Then, a plurality of resonant circuits 8 whose resonance points are set at double frequency series are inserted into the negative feedback circuit of the equalizer amplifier 4, and the feedback ratio of each resonant circuit 8 is controlled to obtain desired frequency characteristics. ing.

Reference numeral 9 denotes a plurality of band filters provided corresponding to each resonance frequency of the resonance circuit 8, and selects and extracts the signal applied via the first switch 3 for each band. The output signal of the bandpass filter 9 is then applied to a drive circuit 10 and displayed on a display 11 according to its level. Further, the output signal of the bandpass filter 9 is applied via a third switch 12 to an analog-to-digital converter (referred to as an A/D converter) 13 for digital conversion. This digital signal is then processed by a microprocessor (CPU).
(abbreviated as ) to 14 bus lines. The CPU calculates the digital signal using software preset in the memory 15, and supplies the compensation signal to a digital-to-analog converter (hereinafter referred to as a D/A converter) 16 for analog conversion. This analog signal is applied to the resonance circuit 8 corresponding to the frequency of the band filter 9 through the switch 12, and the amount of feedback is controlled by electronic or mechanical means such as a servo motor according to the amount of compensation. .

The present invention relates to an improvement of the fader volume position control mechanism for setting the frequency characteristics in the above-mentioned graphic equalizer.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the block diagram shown in FIG. 2, which shows only one of the plurality of fader volumes. In Fig. 2, reference numeral 21 is a double volume, one of which 21a is a fader volume for setting frequency characteristics, and the other 21b is a position detection volume for detecting the position of the slider of the fader volume 21a. be. A DC voltage is applied to both ends of the position detection volume 21b, and a voltage V ₁ corresponding to the position of the slider is obtained from the slider, and this voltage is applied to one input of the comparator 22. A microprocessor (hereinafter abbreviated as CPU) 23 supplies a multi-bit digital signal D that increases or decreases sequentially to a D/A converter 24 for analog conversion, for example, according to a preset program.
This converted output V ₂ is applied to the other input of the comparator 22. Then, in the comparator 22, the values of both input signals V ₁ and V ₂ are compared and the matching signal is sent to the CPU 2.
Give to 3. Therefore, from this coincidence signal, a digital signal D corresponding to the value of the voltage _V1 of the slider of the position detection volume 21b is obtained. Therefore, this digital signal D, for example,
By storing it in the memory of the CPU 23, the position of the position detection volume 21b can be indirectly stored.

On the other hand, in a configuration in which the slider of the dual volume 21 can be driven by the motor 25 or the like, the rotation control of the motor 25 may be performed from the CPU 23 via the motor drive circuit 26. In this way, the position of the slider of the double volume 21 can be controlled in accordance with the digital signal D of the CPU 23.

With such a configuration, for example, when the fader volume 21a is now driven to the position of pre-stored data or data obtained as a calculation result, the digital signal D corresponding to this position is sent.
It is given from the CPU 23 to the A/D converter 24. Then, the output V ₂ of the A/D converter 24 and the voltage V ₁ of the slider of the position detection volume 21b are compared by the comparator 22, and the motor drive circuit 26 is activated by the output signal of the CPU 23 so that the two match. The position of the slider of the double volume 21 can be controlled by driving the motor 25 via the motor 25.

That is, according to the above embodiment, the position of the fader volume 21a can be detected and its contents can be stored as a digital signal, and the position of the fader volume 21a can be controlled according to the stored digital signal or appropriate calculation results. be able to.

It goes without saying that the CPU 23 in the above embodiment can be used in common, for example, in a graphic equalizer as shown in FIG. 1 by programming it to also perform arithmetic processing on the output level of each band filter. be.

Therefore, by using one of the two volumes for position detection, position detection and position control can be performed digitally with a simple configuration, and these positions can be stored or reproduced digitally.

Note that the present invention is not limited to the above-mentioned embodiments, and for example, as shown in FIG. 3, a window comparator 27 that obtains a comparison output within a predetermined upper and lower limit range may be used as the comparator 22. . In this way, it is possible to accurately convert analog signals and digital signals, and in particular, there is an advantage that accurate signal conversion can be performed even against mechanical system operation delays, overshoots, etc.

As detailed above, the present invention provides a position detection volume that is linked to a fader volume that sets frequency characteristics for each of the plurality of resonant frequencies. The signal is given to a comparator and compared with the analog output of the digital-to-analog converter, and the above-mentioned digital and analog outputs are adjusted so that the contents match.
A microprocessor is provided for supplying sequentially changing digital signals to the analog converter or for controlling the operating positions of the fader volume and the position detection volume. Therefore, it is possible to provide a graphic equalizer that can digitally detect the position of the fader volume or control the position according to the stored contents with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a graphic equalizer, FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a block diagram showing another embodiment of the present invention. 21...Double volume, 22...Comparator, 2
3...Microprocessor, 24...Digital
Analog converter, 25... motor, 26... motor drive circuit.

Claims (1)

[Claims for Utility Model Registration] (1) In an equalizer amplifier having a plurality of resonant circuits, the characteristics of which are increased or decreased for each resonant frequency of the resonant circuit according to a set value set by a fader volume, Comparison of a position detection volume that outputs an analog signal according to the operating position in conjunction with the fader volume, a comparator that compares the position detection volume and the respective outputs of the digital/analog converter, and this comparator. and a microprocessor for supplying sequentially changing digital signals to the digital-to-analog converter or controlling the operating positions of the fader volume and the position detecting volume so that the outputs match the contents thereof. Graphic equalizer. (2) A graphical equalizer according to claim 1 of the utility model registration, characterized in that a window type comparator having set values at upper and lower limits is used as the comparator.