RU2775158C1 - Four-band filter for acoustic system - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention relates to acoustics. The filter for a four-band speaker system contains a low-pass filter LC filter, a low-mid-pass LC filter, a mid-pass filter and a high-pass LC filter, the outputs of which are intended for connecting dynamic heads of the low-frequency, low-mid-frequency, mid-frequency and high-frequency ranges, respectively, while the first input of the four-band filter is connected to the first terminal of the first capacitor and the first terminal of the first inductor, the latter is connected by its second terminal to the first terminal of the low-midrange dynamic head, the first terminal of the low-frequency range dynamic head and the first terminal of the second capacitor, the second terminal of the first capacitor is connected to the first terminal of the third capacitor, the first terminal of the second inductor and the second terminal of the low-frequency range dynamic head, the second capacitor the second output is connected to the first output of the fourth capacitor, the first output of the third inductor and the second output of the low-frequency dynamic head, the second output of the fourth capacitor is connected to the first output of the midrange dynamic head, which is connected by the second output to the first output of the fifth capacitor and to the first output of the sixth capacitor, the second output of the second inductor is connected to the second the output of the third inductor, the second output of the fifth capacitor and to the second input of the four-band filter, the sixth capacitor is connected by its second terminal to the first terminal of the dynamic head of the high-frequency range, which is connected by the second terminal to the second terminal of the third capacitor, while the first, second and third inductors have an equal inductance value, the first, fourth and fifth capacitors have an equal capacitance value, and the capacitance the third capacitor is equal to the capacitance of the sixth capacitor.

EFFECT: simplifying the design, increasing the linearity of the phase-frequency characteristic of the filter while maintaining the uniformity of its amplitude-frequency characteristic.

1 cl, 1 dwg

Description

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

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

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

Closest to the invention in terms of technical essence and achieved technical result is a four-band filter for an acoustic system, containing a low-pass filter LC filter, a low-mid-pass LC filter, a mid-pass LC filter and a high-pass LC filter, the outputs of which are designed to connect dynamic heads, respectively, low-frequency, low-mid-frequency, mid-frequency and high-frequency ranges, see US patent No. 10701487, class. H04R 3/04, publ. 06/10/2020, fig. 5).

This filter allows you to improve the fidelity of sound reproduction, the stability of technical characteristics and provides a more even distribution of loads on each dynamic head. However, this filter has a complex design with the need to use a large number of capacitors and inductors, but it does not provide the necessary linearity of the phase-frequency response.

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

The technical result achieved in the invention lies in the fact that an increase in the linearity of the phase-frequency characteristic of the filter is achieved while maintaining the uniformity of its amplitude-frequency characteristic and simplifying the design of a four-band filter for an acoustic system.

The specified technical problem is solved, and the technical result is achieved due to the fact that the filter for a four-band speaker system contains a low-pass LC filter, a low-mid-frequency LC filter, a mid-frequency filter and a high-frequency LC filter, the outputs of which are designed to connect dynamic heads, respectively, low-frequency, low-mid-frequency, mid-frequency and high-frequency ranges, while the first input of the four-band filter is connected to the first output of the first capacitor and the first output of the first inductor, the latter is connected by the second output to the first output of the dynamic head of the lower-mid-frequency range, the first output of the dynamic head of the low-frequency range and the first output of the second capacitor, the second output of the first capacitor is connected to the first terminal of the third capacitor, the first terminal of the second inductor and the second terminal of the dynamic low-midrange head, the second capacitor is the second terminal is connected to the first terminal of the fourth capacitor, the first terminal of the third inductor and the second terminal of the low-frequency dynamic head, the second terminal of the fourth capacitor is connected to the first terminal of the midrange dynamic head, which is connected by the second terminal to the first terminal of the fifth capacitor and to the first terminal of the sixth capacitor , the second terminal of the second inductor is connected to the second terminal of the third inductor, the second terminal of the fifth capacitor and to the second input of the four-band filter, the sixth capacitor is connected by the second terminal to the first terminal of the dynamic head of the high-frequency range, which is connected by the second terminal to the second terminal of the third capacitor, while the first, second, and third inductors have the same inductance, the first, fourth, and fifth capacitors have the same capacitance, and the third capacitor has the same capacitance as the sixth capacitor.

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

This 4-band filter has a combined series-parallel LC circuit, where the amplitude-frequency characteristic (AFC) is distinguished and the phase-frequency characteristic (PFC) is phased in the ranges of low frequencies (LF), low-mid frequencies (LF), medium frequencies (MF) and high frequencies (HF). In this case, the sum of the selected signals is equal to the input voltage signal.

The four-band filter includes a series circuit LF - HF and a series circuit LF - MF. These circuits are interdependent, the signal to the dynamic head of the midrange passes through the dynamic head of the low frequency and is also reproduced by it. The bass and bass drivers have a common coil L1. The dynamic heads of the treble and midrange have a common pass capacitor C2.

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

As a result, the first capacitor of the low-pass LC filter is pass-through for HF to the dynamic head of the high-frequency range, and also shunts the dynamic heads, respectively, LF, LF and MF.

The sixth and third capacitors of the LC high-pass filter are pass-through for high frequencies and bypass the low, low and mid frequencies.

The first inductor of the LC high-pass filter is a pass-through for LF, LF and MF and a shunt for HF.

The fourth capacitor of the mid-range frequency filter is a pass-through for the midrange and a shunt for the high-frequency, low-frequency and low-frequency frequencies.

The second inductor of the LC filter is pass-through for LF and shunt LF, and the third inductor of the LC low-pass filter is pass-through for LF and shunt LF and MF, and the fifth capacitor is pass-through for HF and MF.

In this case, the inductance value of the first, second and third inductors have an equal inductance value (L1=L2=L3).

The first, fourth and fifth capacitors have an equal capacitance value (C1=C4=C5), and the capacitance of the third capacitor is equal to the capacitance of the sixth capacitor (C3=C6).

This improves the range response and consistency of the dynamic heads.

Thus, the second, fourth and fifth capacitors filter the signal to the dynamic head of the mid-frequency range (MF), and the dynamic head of the lower-mid-frequency range (LF) simultaneously reproduces the MF signal.

The dynamic head of the high-frequency range (HF) is connected in series with symmetrical filtering by the third and sixth capacitors (C3=C6).

Also, the dynamic heads one of the low-frequency range (LF) and the second of the low-mid-frequency range (LF) with an equal value of the inductance of the inductors (L1=L2=L3) create an overall harmony (quality) of reproduction in the entire low-frequency range and the lower part of the mid-frequency range.

Thus, the four-band speaker filter described above is universal for any speaker systems (car, home, concert, and similar speakers.

The drawing shows a schematic diagram of a filter for a four-way speaker system.

A four-band filter for an acoustic system contains a low-pass LC filter, a low-mid-pass LC filter, a mid-pass filter, a high-pass LC filter, the outputs of which are designed to connect dynamic heads, respectively, low-frequency, low-mid-frequency, mid-frequency and high-frequency ranges.

The first input 1 of the four-band filter is connected to the first output of the first capacitor 2 and the first output of the first inductor 3, the latter is connected by the second output to the first output of the dynamic head 4 of the low-mid frequency range, the first output of the dynamic head 5 of the low-frequency range and the first output of the second capacitor 6, the second output of the first capacitor 2 is connected to the first output of the third capacitor 7, the first output of the second inductor 8 and the second output of the dynamic head 4 of the low-mid-frequency range, the second output of the second capacitor 6 is connected to the first output of the fourth capacitor 9, the first output of the third inductor 10 and the second output of the dynamic head 5 low-frequency range, the second output of the fourth capacitor 9 is connected to the first output of the dynamic head 11 of the mid-frequency range, which is connected by the second output to the first output of the fifth capacitor 12 and to the first output of the sixth capacitor 13.

The second output of the second inductor 8 is connected to the second output of the third inductor 10, the second output of the fifth capacitor 12 and to the second input 14 of the four-band filter.

The sixth capacitor 13 is connected by the second output to the first output of the dynamic head 15 of the high-frequency range, which is connected by the second output to the second output of the third capacitor 7.

The first 3, the second 8 and the third 10 inductors have an equal inductance value.

The first 2, fourth 9 and fifth 12 capacitors have an equal capacitance, and the capacitance of the third capacitor 7 is equal to the capacitance of the sixth capacitor 13.

In the above-described filter, the LC low-pass filter for the low-frequency driver 5 separates signals with frequencies below 400 Hz as signals supplied to the low-frequency driver 5, and signals with frequencies above 400 Hz as described above are not passed by this. filter. To do this, the low-frequency signal passes through the first inductor 3, the dynamic head 5 of the low-frequency range and the third inductor 10. The low-frequency signals are shunted by the first capacitor 2.

The LC high-pass filter for the high-frequency driver 15 separates signals with frequencies above 5-6 kHz as signals for the dynamic head 15, for which the high-frequency signal passes through the first capacitor 2, the third capacitor 7, the high-frequency driver 15 and the sixth capacitor 13 and further through the fifth capacitor 12. Signals with frequencies below 5-6 kHz are not passed through this filter. High-frequency signals are shunted by the first inductor 3.

The total range of signals that are suppressed by the low-pass and high-pass LC filters ("extended midrange") is wider than the operating frequency band that can be reproduced qualitatively by the midrange dynamic head 11. To do this, the lower part of the mid-frequency range in total with the mid-frequency range is reproduced by the dynamic head 4 of the lower-mid-frequency range, which allows the mid-frequency range to pass through it and at the same time, by means of the second inductor 8, to shunt the low-frequency and high-frequency ranges. The "extended" mid-frequency signal, which is not reproduced by the dynamic heads 5 and 15, passes through the first inductor 3, the dynamic head 4 of the low-mid range and the second inductor 8, shunting the low-frequency signal. At the same time, the "extended" mid-frequency signal passes after the first inductor 3 and further through the second capacitor 6, shunting the low-frequency signal, the fourth capacitor 9, shunting the lower part of the "extended" mid-frequency range, the dynamic head 11 of the mid-frequency range and then passes to the second input 14 through the fifth capacitor 12, wherein the fifth capacitor 12 shunts the low frequency signal. Thus, the midrange driver 11 receives a signal corresponding to the midrange.

As a result, the linearity of the phase-frequency characteristic of a four-band filter, 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 playing various sounds, which as a result improves the quality of reproduction of various kinds of sounds by the above-described four-band acoustic system.

Claims (1)

A four-band filter for an acoustic system, containing a low-pass filter LC filter, a low-mid-pass LC filter, a mid-pass filter and a high-pass LC filter, the outputs of which are designed to connect dynamic heads, respectively, low-frequency, low-mid-frequency, mid-frequency and high-frequency ranges, characterized in that the first input of a four-band filter is connected to the first output of the first capacitor and the first output of the first inductor, the latter is connected by the second output to the first output of the dynamic head of the low-mid range, the first output of the dynamic head of the low frequency range and the first output of the second capacitor, the second output of the first capacitor is connected to the first output of the third capacitor, the first the output of the second inductor and the second output of the dynamic head of the low-mid-frequency range, the second capacitor is connected by the second output to the first output of the fourth capacitor, the first the output of the third inductor and the second output of the dynamic head of the low-frequency range, the second output of the fourth capacitor is connected to the first output of the dynamic head of the mid-frequency range, which is connected by the second output to the first output of the fifth capacitor and to the first output of the sixth capacitor, the second output of the second inductor is connected to the second output of the third inductor, the second terminal of the fifth capacitor and to the second input of the four-band filter, the sixth capacitor is connected by the second terminal to the first terminal of the dynamic head of the high-frequency range, which is connected by the second terminal to the second terminal of the third capacitor, while the first, second and third inductors have an equal value inductance, the first, fourth and fifth capacitors have an equal value of capacitance, and the capacitance of the third capacitor is equal to the capacitance of the sixth capacitor.

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