RU2820881C1 - Four-band filter for acoustic system - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: filter for acoustic system contains four filters, outputs of which are intended for connection of loudspeakers. Low-pass filter consists of first, second and third inductance coils, high-low-pass filter consists of fourth inductance coil, medium-pass filter consists of seven, first-seventh capacitors, and high-pass filter consists of fifteen, eighth-twenty-second capacitors. First output of dynamic head of low-low-frequency range is connected to second output of first inductance coil, which first output is connected to the second inductance coil second output, and its first output is connected to the "plus" at the filter input, second output of dynamic head of low-low-frequency range is connected to the first output of the third inductance coil, and its second output is connected to "minus" at the input to the filter. First output of the high-low-frequency range speaker is connected to the second output of the fourth inductance coil, the first output of the fourth inductance coil is connected to the "plus" at the input to the filter, and second output of dynamic head of high-low frequency range is connected to "minus" at input to filter, first-fourth capacitors are connected in series, wherein first output of first capacitor is connected to the plus at input to filter, and the second output of the fourth capacitor is connected to the first output of the dynamic head of the medium-frequency range, the fifth-seventh capacitors are connected in series.

EFFECT: high linearity of the phase-frequency characteristic of the device while maintaining uniformity of its amplitude-frequency characteristic and simplifying the design.

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Description

The invention relates to radio engineering and can be used in acoustic systems of household or professional sound-reproducing equipment.

A four-band device for an acoustic system is known, containing a low-frequency LC filter, a mid-frequency LC filter and two parallel high-frequency LC filters, the outputs of which are designed to connect dynamic heads of low-frequency, mid-frequency and two high-frequency ranges (see international application WO 81/00947, class . H04R 3/12, published 04/02/1981, fig.

This device has a simple design, but does not provide the required sound quality in the low-frequency range, which is due to the fact that it does not provide signal separation at low frequencies during playback, which leads to blurred localization of apparent sound sources.

The closest to the invention in technical essence and the achieved technical result is a filter for an acoustic system containing a low-low-pass filter, a high-low-pass filter, a mid-frequency filter and a high-frequency filter, and the output of these filters is connected to the dynamic heads, respectively, low-low-frequency, high-frequency -low-frequency, mid-frequency and high-frequency ranges (see US patent No. 10701487, class H04R 3/14, published 06/10/2020, Fig. 5).

This device improves the accuracy of sound reproduction, the stability of technical characteristics and ensures a more even distribution of loads on each dynamic head. However, it has a complex design with the need to use a large number of capacitors and inductors, but this does not ensure the necessary linearity of the phase-frequency characteristic.

The technical problem to be solved by the present invention is to overcome the above-mentioned disadvantages.

The technical result is that an increase in the linearity of the phase-frequency response of the device is achieved while maintaining the uniformity of its amplitude-frequency response and simplifying the design.

The specified technical problem is solved, and the technical result is achieved due to the fact that the four-band filter for the acoustic system contains a low-low-pass filter, a high-low-pass filter, a mid-frequency filter and a high-frequency filter, the outputs of which are intended for connecting dynamic heads, respectively, low-low-frequency, high-frequency low-frequency, mid-frequency and high-frequency ranges, the low-pass filter consists of the first, second and third inductors, the high-low-pass filter consists of the fourth inductor, the mid-pass filter consists of seven, first to seventh, capacitors, and the high-pass filter consists of fifteen, eighth-twenty-second, capacitors, while the first terminal of the dynamic head of the low-low frequency range is connected to the second terminal of the first inductor, the first terminal of which is connected to the second terminal of the second inductor, and its first terminal is connected to the “plus” at the input filter, the second terminal of the dynamic head of the low-low frequency range is connected to the first terminal of the third inductor, and its second terminal is connected to the “minus” at the input to the filter, while the first terminal of the dynamic head of the high-low frequency range is connected to the second terminal of the fourth inductor, the first terminal of the fourth inductor is connected to the “plus” at the input to the filter, and the second terminal of the dynamic head of the high-low frequency range is connected to the “minus” at the input to the filter, the first to fourth capacitors are connected in series, and the first terminal of the first capacitor is connected to the “plus” at the input to the filter, and the second terminal of the fourth capacitor is connected to the first terminal of the mid-range dynamic head, the fifth-seventh capacitors are connected in series, with the first terminal of the fifth capacitor connected to the second terminal of the mid-range dynamic head, and the second terminal of the seventh capacitor is connected to the minus "at the input to the filter, the eighth - fifteenth capacitors are connected in series, while the second output of the fifteenth capacitor is connected to the first output of the dynamic head of the high-frequency range, and the first output of the eighth capacitor is connected to the “plus” at the input to the filter, the sixteenth to twenty-second capacitors are connected in series , while the second terminal of the twenty-second capacitor is connected to the second terminal of the dynamic head of the high-frequency range, and the first terminal of the sixteenth capacitor is connected to the “minus” at the input to the filter, and the inductance values of the first, second and third inductors are equal, and the capacitance values of the first-seventh coils are equal capacitors and are equal to the capacitance values of the eighth to twenty-second capacitors.

Thus, the device includes four parallel circuits, namely two inductive ones, which form the LLF and VLF filters, and two capacitive ones, which form the midrange and high-pass filters, which are harmonized with each other in terms of parameters and directivity, and the dynamic heads of the LLF and VLF do not have common coils inductance, and the HF and MF dynamic heads do not have common pass-through capacitors.

The above, combined with the fact that the device has a parallel structure, and parallel installed inductors and capacitors in the filters, respectively, have the same inductance and capacitance, increases the range output and consistency of operation of the LLF and VLF dynamic heads, as well as the midrange and high-frequency dynamic heads.

This solution allows you to expand the frequency range (AFC) of the system and achieve phase consistency (PFC).

Thus, to the dynamic head of the high-frequency range (HF), the signal is filtered by series-connected capacitors from seven to fifteen and from sixteen to twenty-second, to the dynamic head of the mid-frequency range (MF), the signal is filtered by series-connected capacitors from first to fourth and from fifth to seventh, and to the dynamic head of the high-low frequency range (HLF) the signal is filtered by the fourth coil and to the dynamic head of the low-low frequency range (LF) the signal is filtered by the first and second inductors connected in series and the third inductor.

As a result, the dynamic heads of the LLF and VLF ranges create an overall harmony (quality) of reproduction in the entire range of low frequencies, and the dynamic heads of the midrange and HF ranges create an overall harmony (quality) of reproduction in the entire range of mid and high frequencies.

As a result, an increase in the linearity of the phase-frequency response of the device is achieved while maintaining the uniformity of its amplitude-frequency response, providing the required separation (AFC) and matching (PFC) of the dynamic heads.

Thus, the device is universal for any acoustic systems (car, household, concert and similar acoustic systems).

The drawing shows a schematic diagram of the device.

The filter for the acoustic system contains a low-low-pass filter (LPF), a high-low-pass filter (HLF), a mid-frequency filter (MF) and a high-frequency filter (HF), the outputs of which are intended for connecting dynamic heads 1, 2, 3 and 4, respectively, low-low-frequency, upper-low-frequency, mid-frequency and high-frequency ranges.

The low-pass filter consists of the first 5, second 6 and third 7 inductors.

The high-low-pass filter consists of a fourth inductor 8.

The mid-pass filter consists of the first 9, second 10, third 11, fourth 12, fifth 13, sixth 14 and seventh 15 capacitors.

The high-pass filter consists of eighth 16, ninth 17, tenth 18, eleventh 19, twelfth 20, thirteenth 21, fourteenth 22, fifteenth 23, sixteenth 24, seventeenth 25, eighteenth 26, nineteenth 27, twentieth 28, twenty-first 29 and twenty-second 30 capacitors.

The first output of the dynamic head of the low-low frequency range 1 is connected to the second output of the first inductor 5, the first output of which is connected to the second output of the second inductor 6, and its first output is connected to “plus” 31 at the input to the filter, the second output of the dynamic head is lower -low-frequency range 1 is connected to the first terminal of the third inductor 7, and its second terminal is connected to “minus” 32 at the input to the filter.

The first terminal of the dynamic head of the high-low frequency range 2 is connected to the second terminal of the fourth inductor 8, the first terminal of the fourth inductor 8 is connected to the “plus” 31 at the input to the filter, and the second terminal of the dynamic head of the high-low frequency range 2 is connected to the “minus” 32 at the inlet to the filter.

The first 9, second 10, third 11 and fourth 12 capacitors are connected in series, with the first output of the first capacitor 9 connected to the “plus” 31 at the input to the filter, and the second output of the fourth capacitor 12 connected to the first output of the mid-range dynamic head 3. The fifth 13, sixth 14 and seventh 15 capacitors are connected in series, with the first terminal of the fifth capacitor 13 connected to the second terminal of the mid-range dynamic head 3, and the second terminal of the seventh capacitor 15 is connected to minus 32 at the input to the filter.

The eighth 16, ninth 17, tenth 18, eleventh 19, twelfth 20, thirteenth 21, fourteenth 22 and fifteenth 23 capacitors are connected in series. The second terminal of the fifteenth capacitor 23 is connected to the first terminal of the dynamic head of the high-frequency range 4, and the first terminal of the eighth capacitor 16 is connected to “plus” 31 at the input to the filter. The sixteenth 24, seventeenth 25, eighteenth 26, nineteenth 27, twentieth 28, twenty-first 29 and twenty-second 30 capacitors are connected in series, with the second terminal of the twenty-second 30 capacitor connected to the second terminal of the dynamic head of the high-frequency range 4, and the first terminal of the sixteenth capacitor 24 connected to minus 32 at the filter inlet.

In this case, the inductance values of the first 5, second 6 and third 7 inductors are equal.

The capacitance values of the first 9, second 10, third 11, fourth 12, fifth 13, sixth 14 and seventh 15 capacitors are equal.

The capacitance values of the eighth 16, ninth 17, tenth 18, eleventh 19, twelfth 20, thirteenth 21, fourteenth 22, fifteenth 23, sixteenth 24, seventeenth 25, eighteenth 26, nineteenth 27, twentieth 28, twenty-first 29 and twenty-second 30 capacitors are equal .

In this device, the low-frequency filter is represented by the first inductor 5 and the second inductor 6 and the third inductor 7, intended for the dynamic head 1 of the low-low frequency range, which selects signals with frequencies below 200 Hz, i.e. for the lower part of the low-frequency range, and signals with a frequency below 200 Hz are not reproduced by the dynamic head 1 LLF.

Signals with frequencies above 200 Hz, as described above, are not passed by this filter formed by the first 5, second 6 and third 7 inductors, and the high-low-pass filter formed by the fourth inductor 8 does not pass signals below 200 Hz.

High-pass filter consisting of eighth 16, ninth 17, tenth 18, eleventh 19, twelfth 20, thirteenth 21, fourteenth 22, fifteenth 23, sixteenth 24, seventeenth 25, eighteenth 26, nineteenth 27, twentieth 28, twenty-first 29 and twenty the second 30 capacitors are intended for the dynamic head of the high-frequency range 4 and select signals with frequencies above 5-6 kHz, for which the high-frequency signal passes in series through capacitors from the eighth capacitor 16 to the fifteenth capacitor 23 and the dynamic head of the high-frequency range 4 and then passes in series through capacitors with twenty-second 30 to sixteenth capacitor 24. Signals with frequencies below 5-6 kHz are not passed by this filter.

Mid-range signals are passed through a mid-frequency filter formed by the first 9, second 10, third 11, fourth 12, fifth 13, sixth 14 and seventh 15 capacitors and are reproduced by the dynamic head of the mid-range 3.

Thus, the dynamic head of the mid-frequency range 3 receives a signal corresponding only to the mid-frequency range.

As a result, the linearity of the phase-frequency response of the device while maintaining the uniformity of its amplitude-frequency response makes it possible to improve the quality of the stereo effect, reduce the inaccuracy in the perception of the position of sound sources and reduce distortion when reproducing various sounds, which as a result improves the quality of reproduction of various types of sounds.

Claims (1)

A four-band filter for an acoustic system, containing a low-low-pass filter, a high-low-pass filter, a mid-frequency filter and a high-frequency filter, the outputs of which are intended for connecting dynamic heads, respectively, of the low-low-frequency, upper-low-frequency, mid-frequency and high-frequency ranges, characterized in that the low-frequency the low-pass filter consists of the first, second and third inductors, the high-low-pass filter consists of the fourth inductor, the mid-pass filter consists of seven, first-seventh capacitors, and the high-pass filter consists of fifteen, eighth-twenty-second capacitors, with In this case, the first output of the dynamic head of the low-low frequency range is connected to the second terminal of the first inductor, the first output of which is connected to the second terminal of the second inductor, and its first output is connected to the “plus” at the input to the filter, the second output of the dynamic head of the low-low frequency range connected to the first terminal of the third inductor, and its second terminal is connected to the “minus” at the input to the filter, while the first terminal of the dynamic head of the high-low frequency range is connected to the second terminal of the fourth inductor, the first terminal of the fourth inductor is connected to the “plus” at the input to the filter, and the second output of the dynamic head of the high-low frequency range is connected to the “minus” at the input to the filter, the first through fourth capacitors are connected in series, and the first output of the first capacitor is connected to the “plus” at the input to the filter, and the second output of the fourth capacitor is connected to the first terminal of the dynamic head of the mid-frequency range, the fifth-seventh capacitors are connected in series, while the first terminal of the fifth capacitor is connected to the second terminal of the dynamic head of the mid-frequency range, and the second terminal of the seventh capacitor is connected to the “minus” at the input to the filter, the eighth-fifteenth the capacitors are connected in series, with the second terminal of the fifteenth capacitor connected to the first terminal of the dynamic head of the high-frequency range, and the first terminal of the eighth capacitor is connected to the “plus” at the input to the filter, the sixteenth to twenty-second capacitors are connected in series, with the second terminal of the twenty-second capacitor connected to the second terminal of the dynamic head of the high-frequency range, and the first terminal of the sixteenth capacitor is connected to the “minus” at the input to the filter, and the inductance values of the first, second and third inductors are equal, the capacitance values of the first-seventh capacitors are equal and the capacitance values of the eighth-twenty-second are equal capacitors.

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