RU2243627C2 - Method for distributing signals among loudspeakers - Google Patents

Abstract

FIELD: radio engineering; domestic and professional sound-reproducing equipment.

SUBSTANCE: input audio signal of 30 - 20 000 Hz is divided in active filters into low-, intermediate-, and high-frequency signals; low- and high-frequency signals are summed up, intermediate-frequency signal and sum of low- and high-frequency signals are passed through two amplifiers whereupon amplified intermediate-frequency signal is supplied to intermediate-frequency loudspeaker while sum of low- and high-frequency signals is conveyed through passive low- and high-pass filters to low- and high-frequency loudspeakers. Spacing of frequencies supplied to passive filters in decade enables suppression of other-band channel by minimum 20 dB.

EFFECT: eliminated intermodulation and nonlinear distortions caused by loudspeaker interactivity near branching point.

1 cl, 1 dwg

Description

The invention relates to radio engineering and is intended for use in sound reproducing equipment, household and professional.

The most common method for separating signals between loudspeakers is known, when, after the amplifier, the signals are fed through passive filters to low-frequency (LF), mid-frequency (MF) and high-frequency (HF) loudspeakers. [1] In this case, non-linear distortions occur in the speakers caused by the interactivity of the speakers near the separation point. In addition, power losses are inevitable in passive filter components.

The closest in technical essence and the achieved result is a two-way amplification method [2], which eliminates non-linear distortions caused by the interactivity of the speakers near the separation point. The signals after separation on the active filter on the LF / MF and HF are fed to different amplifiers. After that, the signals are fed to the woofer / midrange loudspeaker and the tweeter. The combination of the LF and MF signals on one LF / MF loudspeaker makes it wideband, which inevitably leads to the appearance of intermodulation distortions in the signal. [2].

The objective of the proposed technical solution is to create a method for distributing signals between speakers, which eliminates intermodulation distortion and non-linear distortion caused by the interactivity of the speakers near the separation point.

The problem is solved by the method of distributing signals between the speakers, in which the input signal is separated in the active filter, amplified and fed to the speakers, while the input sound signal (30-20000 Hz) in the active filter is divided into low-frequency, mid-frequency and high-frequency signals, low-frequency and the high-frequency signals are summed, the mid-frequency signal and the summed low-frequency and high-frequency signals are amplified by two amplifiers, after which the mid-frequency signal is fed to the midrange kogovoritel, and the summed low frequency with the high frequency signal through a passive filter LF and HF fed to the LF and RF speakers.

The spacing of frequencies applied to passive filters in a decade allows to suppress a signal of another range of at least 20 dB, even when using first-order filters.

Thus, the proposed method for distributing signals between loudspeakers, in comparison with the known ones, provides a reduction in non-linear and intermodulation distortions.

The use of the proposed technical solution in sound reproducing equipment allows to improve the sound quality, especially in the mid-frequency range, in which the sensitivity of hearing is maximum. [3].

The essence of the proposed technical solution is illustrated in FIG. 1, which shows a block diagram of the distribution of signals between the speakers, where 1 is an active low-pass filter, 2 is an active low-pass filter, 3 is an additional function filter, 4 is an additional function filter, 5 is an adder low frequencies (LF) and high frequencies (HF), 6 - amplifier, 7 - amplifier, 8 - mid-range speaker (MF), 9 - passive low-pass filter (LF), 10 - low-frequency speaker (LF), 11 - passive high-pass filter (HF), 12 - high-frequency loudspeaker stot (HF), 13 - active high-pass filter unit, 14 - active medium-frequency filter unit, a - first input of an additional function filter 3, b - second input of an additional function filter 3, c - first input of an additional function filter 4, d - the second filter input of the additional function 4, e is the first input of the adder 5, g is the second input of the adder 5.

The block diagram for implementing the proposed method is connected as follows. The output of the active low-pass filter 1 is connected to the input b of the filter of the additional function 3 and constitutes the active high-pass filter block 13, the output of which is connected to the input g of the adder 5. The output of the active low-pass filter 2 is connected to the input d of the filter of the additional function 4 and constitutes the active block a medium-pass filter 14, the output of which is connected to the input of an amplifier 6, the output of which is connected to a mid-range loudspeaker 8. The output of an active low-pass filter 2 is connected to the input e of the adder 5, the output of which the second is connected to the input of the amplifier 7. The output of the amplifier 7 through a passive low-pass filter 9 is connected to the woofer LF 10, and through a passive high-pass filter (HF) 11, is connected to the loudspeaker of the high frequencies (HF) 12.

The method is as follows. The input sound signal (30-20000 Hz) is fed to the input of the active high-pass filter unit 13, where the signal is separated and fed simultaneously to the active low-pass filter 1 and to the input a of the filter of the additional function 3. From the output of the active low-pass filter 1, the signal ( 30-3000 Hz) fed to the input b of the filter of the additional function 3 of the active high-pass filter unit 13, the output of which the RF signal (3000-20000 Hz) is fed to the input g of the adder 5. From the output of the active low-pass filter 2, the low-frequency signal (30- 300 Hz) are fed to the input d of the filter of additional function 4, from the output which the MF signal (300-3000 Hz) is fed to the input of the amplifier 6, and from it to the MF loudspeaker 8, which improves the sound quality in the mid-frequency range. From the output of the active low-pass filter 2, the low-frequency signal (30-300 Hz) is fed to the input e of the adder 5, the output of which the total low-frequency and high-frequency signal with a frequency span of a decade (300-3000 Hz) is fed to the input of the amplifier 7, the output signal of which separated by passive filters LF 9 and HF 11 and served respectively on the LF loudspeaker 10 and HF loudspeaker 12, while providing a reduction in non-linear and intermodulation distortion.

Sources of information

1. The journal "Sound engineer", No. 6, 2000, p. 37.

2. The journal "Sound engineer", No. 6, 2000, p. 5-6.

3. The journal "Sound Engineer". No. 9, 2001, p. 3-9.

Claims (2)

1. A method of distributing signals between loudspeakers, in which the input signal of 30-20000 Hz is separated in active filters into low-frequency, mid-frequency and high-frequency signals, amplified and fed to loudspeakers, characterized in that the low-frequency and high-frequency signals are summed, the mid-frequency signal and the summed low-frequency signal the high-frequency signal is amplified on two amplifiers, after which the mid-frequency signal is fed to the loudspeaker for reproducing medium frequencies, and the summed low-frequency signal With the high-frequency signal, passive low-pass and high-pass filters are fed to the speakers for reproducing low and high frequencies. 2. The method according to claim 1, characterized in that the summed low-frequency with high-frequency signal is fed to an amplifier with a frequency spacing of 300-3000 Hz per decade.