CN110958536A

CN110958536A - Bass loudspeaker box for realizing heart-shaped directional radiation

Info

Publication number: CN110958536A
Application number: CN201911182068.5A
Authority: CN
Inventors: 曾山
Original assignee: Maloney Guangzhou Technology Development Co Ltd
Current assignee: Maloney Guangzhou Technology Development Co Ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-04-03

Abstract

The invention discloses a bass sound box for realizing heart-shaped directional radiation, which comprises a shell, a direct and inverse bass loudspeaker unit and a six-order band-pass bass loudspeaker unit, wherein the direct and inverse bass loudspeaker unit and the six-order band-pass bass loudspeaker unit are arranged in the shell; the acoustic distance between the sound source radiation openings of the two is equal to 1/4 wavelengths of the front cavity tuning frequency of the six-order band-pass type bass loudspeaker unit; the direct-radiation and phase-inversion type bass loudspeaker unit is connected with the six-order band-pass type bass loudspeaker unit in an opposite polarity mode. The direct-injection phase-reversal type loudspeaker unit and the six-order band-pass type loudspeaker unit are combined for use, so that ultralow-frequency heart-shaped directional radiation is realized, a digital signal processor is not required to be used for delay processing, only one path of external power amplifier channel is required, and the complexity and the equipment cost of equipment are greatly reduced.

Description

Bass loudspeaker box for realizing heart-shaped directional radiation

Technical Field

The invention relates to the technical field of directional ultralow frequency sound boxes, in particular to a bass sound box capable of realizing heart-shaped directional radiation.

Background

The conventional bass frequency band wavelength is longer than the sound source size, the radiation pattern often presents spherical pointing, and the existing mode for realizing heart-shaped pointing is of two types, one is: the method of adding a horn to a sound source to realize directional control, however, the relatively practical small horn works in the middle and high frequency band, and in the middle and low frequency band below 500Hz, the size of the horn must be larger than one wavelength (0.686 meter) of 500Hz or larger (the wavelength of 100Hz is 3.43 meters), which makes the method of the horn to control the directional of the low frequency sound source not practical in reality. The second is that: two independent power amplifier channels and two independent digital signal processor channels are needed for time delay processing, for example, patent CN 201315664Y-the technical scheme disclosed by the heart-shaped directional sound box needs to respectively drive the forward speaker unit and the backward speaker unit through two independent driving circuits, and the time delay processing is performed through two independent driving circuits, and two power amplifier channels are needed, so that the sound box structure is complex and the cost is too high.

Disclosure of Invention

In order to overcome the defects of the prior art, one of the objectives of the present invention is to provide a bass sound box for implementing cardioid directional radiation, which implements ultralow frequency cardioid directional radiation by using a direct-and-inverse speaker unit and a six-order band-pass speaker unit in combination, without using a digital signal processor for delay processing, and only needing to connect an external power amplifier channel, thereby greatly reducing the complexity of the device and the device cost.

One of the purposes of the invention is realized by adopting the following technical scheme:

a bass loudspeaker box for realizing heart-shaped directional radiation comprises a shell, and further comprises a direct-phase-inversion type bass loudspeaker unit and a six-order band-pass type bass loudspeaker unit which are arranged in the shell, wherein the direct-phase-inversion type bass loudspeaker unit is positioned in front of the six-order band-pass type bass loudspeaker unit, and the directions of sound source radiation openings of the direct-phase-inversion type bass loudspeaker unit and the six-order band-pass type bass loudspeaker unit are opposite; an acoustic distance between the sound source radiation port of the direct phase reversal woofer unit and the sound source radiation port of the sixth-order band-pass woofer unit is equal to 1/4 wavelengths of a front cavity tuning frequency of the sixth-order band-pass woofer unit; the direct-wave and reverse-wave bass loudspeaker unit is connected with the six-stage band-pass bass loudspeaker unit in a reverse polarity mode.

Furthermore, the direct-radiation phase-inversion type bass loudspeaker unit and the six-order band-pass type bass loudspeaker unit are driven by the single-channel power amplifier driving unit simultaneously.

Furthermore, the direct-and-reverse-phase type bass speaker unit and the six-order band-pass type bass speaker unit are connected in parallel in an antipolar manner, and the single-channel power amplifier driving unit is electrically connected with the direct-and-reverse-phase type bass speaker unit and the six-order band-pass type bass speaker unit respectively.

Further, the direct-and-reverse-phase type bass speaker unit and the six-order band-pass type bass speaker unit are connected in series in a reverse polarity manner, the single-channel power amplifier driving unit is electrically connected to the direct-and-reverse-phase type bass speaker unit and the direct-and-reverse-phase type bass speaker unit is connected to the six-order band-pass type bass speaker unit, or the single-channel power amplifier driving unit is electrically connected to the six-order band-pass type bass speaker unit and the six-order band-pass type bass speaker unit is connected to the direct-and-reverse-phase type bass speaker unit.

Further, the direct phase inversion type woofer unit has two.

Further, the six-order band pass type woofer unit has two.

Compared with the prior art, the invention has the beneficial effects that:

the bass sound box for realizing cardioid directional radiation is used by combining the direct-phase-reversal type loudspeaker unit and the six-order band-pass type loudspeaker unit, and the acoustic distance between the sound source radiation port of the direct-phase-reversal type bass loudspeaker unit and the sound source radiation port of the six-order band-pass type bass loudspeaker unit is adjusted to be equal to 1/4 wavelengths of front cavity tuning frequency of the six-order band-pass type bass loudspeaker unit, so that sound waves on the back side of the bass sound box are offset, sound waves on the front side are superposed, and further, ultralow-frequency cardioid directional radiation is realized; the bass sound box for realizing heart-shaped directional radiation does not need to use a digital signal processor for time delay processing, only needs to be externally connected with one path of power amplifier channel, and greatly reduces the complexity of equipment and the equipment cost.

Drawings

FIG. 1 is a schematic structural view of a bass sound box for realizing cardioid directional radiation according to the present invention;

fig. 2 is a waveform diagram of sound waves emitted by the direct-and-inverse speaker unit and the six-step band-pass speaker unit respectively at a position 8 meters in front of the bass sound box for realizing cardioid directional radiation when the bass sound box provided by the invention is at 50 Hz;

FIG. 3 is a waveform diagram of the bass sound box for realizing cardioid directional radiation according to the present invention after mixing the sound waves of the direct-and-inverse speaker unit and the six-order band-pass speaker unit at 8 meters in front of the sound box at 50 Hz;

fig. 4 is a waveform diagram of sound waves emitted by the direct-and-inverse speaker unit and the six-step band-pass speaker unit respectively at a position 8 meters ahead of the bass loudspeaker box for realizing cardioid directional radiation when the bass loudspeaker box provided by the invention is at 80 Hz;

FIG. 5 is a waveform diagram of the bass sound box for realizing cardioid directional radiation according to the present invention after mixing the sound waves of the direct and inverse speaker unit 8 meters in front of the sound box and the six-step band-pass speaker unit at 80 Hz;

fig. 6 is a waveform diagram of sound waves emitted by the direct-and-inverse speaker unit and the six-step band-pass speaker unit respectively at 8 meters in front of the bass sound box for realizing cardioid directional radiation according to the present invention at 100 Hz;

FIG. 7 is a waveform diagram of the bass sound box for realizing cardioid directional radiation according to the present invention after mixing the sound waves of the direct and inverse speaker unit 8 meters in front of the sound box and the six-step band-pass speaker unit at 100 Hz;

fig. 8 is a waveform diagram of sound waves emitted by the direct-and-inverse speaker unit and the six-order band-pass speaker unit respectively at a position 8 meters behind the bass loudspeaker box for realizing cardioid directional radiation when the bass loudspeaker box provided by the invention is at 50 Hz;

fig. 9 is a waveform diagram of sound waves emitted from the direct-and-inverse speaker unit and the six-order band-pass speaker unit respectively at a position 8 meters behind the bass sound box for realizing cardioid directional radiation at 80Hz according to the present invention;

fig. 10 is a waveform diagram of sound waves emitted from the direct-and-inverse speaker unit and the six-step band-pass speaker unit respectively at 8 meters behind the bass sound box for realizing cardioid directional radiation according to the present invention at 100 Hz;

FIG. 11 is a waveform diagram of the bass loudspeaker enclosure of the present invention for achieving cardioid directional radiation after mixing of the direct and inverse speaker units and the six-step bandpass speaker units at 8 meters behind the enclosure at 50, 80, and 100Hz, respectively;

FIG. 12 is a graph of frequency response at 8 meters front and back of a woofer implementing cardioid directional radiation provided by the present invention simulated using EASE FOCUS 3 acoustic simulation software;

FIG. 13 is a schematic diagram of sound wave radiation at 100Hz of a bass enclosure using EASE FOCUS 3 acoustic simulation software to simulate the heart-shaped directional radiation provided by the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

Referring to fig. 1, a bass loudspeaker box for realizing cardioid directional radiation includes a casing, a stainless steel screen is further disposed on a surface of the casing, and further includes a direct-phase-inversion type bass loudspeaker unit and a sixth-order band-pass type bass loudspeaker unit disposed in the casing, wherein the direct-phase-inversion type bass loudspeaker unit is located in front of the sixth-order band-pass type bass loudspeaker unit, and directions of sound source radiation ports of the direct-phase-inversion type bass loudspeaker unit and the sixth-order band-pass type bass loudspeaker unit are opposite; an acoustic distance between the sound source radiation port of the direct phase reversal woofer unit and the sound source radiation port of the sixth-order band-pass woofer unit is equal to 1/4 wavelengths of a front cavity tuning frequency of the sixth-order band-pass woofer unit; the direct-wave and reverse-wave bass loudspeaker unit is connected with the six-stage band-pass bass loudspeaker unit in a reverse polarity mode.

As a preferred embodiment, the direct and inverse bass loudspeaker unit and the six-order band-pass bass loudspeaker unit are driven by the single-channel power amplifier driving unit at the same time. Through increasing single channel power amplifier drive unit, make this bass speaker become active audio amplifier, need not external power amplifier drive.

In a preferred embodiment, the direct-phase and inverse-phase bass speaker unit and the six-order band-pass bass speaker unit are connected in parallel with each other in an inverse polarity manner, and the single-channel power amplifier driving unit is electrically connected to the direct-phase and inverse-phase bass speaker unit and the six-order band-pass bass speaker unit, respectively. In addition, as a modified embodiment, the direct-phase-inversion type woofer unit and the sixth-order band-pass type woofer unit may also be connected in series with reversed polarity, the single-channel power amplifier driving unit is electrically connected to the direct-phase-inversion type woofer unit and the direct-phase-inversion type woofer unit is connected to the sixth-order band-pass type woofer unit, or the single-channel power amplifier driving unit is electrically connected to the sixth-order band-pass type woofer unit and the sixth-order band-pass type woofer unit is connected to the direct-phase-inversion type woofer unit.

In a preferred embodiment, the direct and phase inversion type woofer unit has two, and the six-step band pass type woofer unit has two. The direct and inverse bass speaker unit and the six-stage band pass bass speaker unit may be one each, or two or more each.

Referring to fig. 1, a direct-phase bass speaker unit is set as a, a sixth-order bandpass bass speaker unit is set as B, an acoustic distance between radiation ports of the two speaker units AB is 0.86 m (equal to 1/4 wavelength of front cavity tuning frequency of the sixth-order bandpass bass speaker unit), a phase from a sound emitted by a to a position 8 m in front of the bass loudspeaker box is Φ FA, and a phase from a to a position 8 m behind the bass loudspeaker box is Φ RA; the phase from the sound emitted by B to the position 8 meters in front of the bass sound box is phi FB, and the phase from the sound emitted by B to the position 8 meters behind the bass sound box is phi RB.

When the acoustic distance L between them is 0.86 m, the original phases of a and B are different by 1/4 wavelengths, the phase of the direct and inverse bass speaker unit a is 0 degree at 100Hz, and when the tuning frequency of the front cavity of the six-order band-pass bass speaker unit B is 100Hz, the phase of the six-order band-pass bass speaker unit B at 100Hz is 90 degrees, that is, 90 degrees phase shift. Furthermore, the drive signal for the B cell is 180 degrees out of phase with respect to the drive signal for the a cell, since the a, B cells are connected with opposite polarity.

Through the above structural arrangement, the sound obtained at 8 meters in front of the bass sound box should be obtained by superposing the unit a and the unit B, and the following is a calculation example under each frequency of the low frequency band:

1. at 50HZ, Φ FA is 0 degrees, and 50HZ phase Φ RA of sound of B unit 8 meters in front of the bass sound box is: 180 degrees (reverse polarity connection) +45 degrees (delay time 2.5 milliseconds due to 0.86 m difference in acoustic distance between units) +45 degrees (phase shift due to the sixth-order band-pass woofer unit) + 270 degrees, and the phase difference between the two is: 270 degrees-0 degrees 270 degrees, signals at the same level that are 270 degrees out of phase are superimposed with 3.01 DB.

2. At 80HZ, Φ FA is 0 degrees, and 80HZ phase Φ RA from the sound of B unit to 8 meters in front of the bass speaker is: 180 degrees (reverse polarity connection) +72 degrees (delay time 2.5 milliseconds due to 0.86 m difference in acoustic distance between units) +72 degrees (phase shift due to the sixth-order band bass speaker unit) × 324 degrees, and the phase difference between the two is: 324 degrees-0 degrees-324 degrees with the same level signals that are 324 degrees out of phase are superimposed by 5.58 DB.

3. At 100HZ, Φ FA is 0 degrees, and 100HZ phase Φ RA of sound of B unit 8 meters in front of the bass sound box is: 180 degrees (reverse polarity connection) +90 degrees (delay 2.5 ms due to 0.86 m difference in acoustic distance between units) +90 degrees (phase shift due to the sixth-order bandpass woofer unit), which is 360 degrees, that is, two sounds are superimposed in phase at 6.02 DB.

While the sounds emitted by the front and rear units at a position 8 meters behind the bass group should cancel each other, the following is a calculation example of different frequencies in the low frequency band:

1. at 50HZ, the phase Φ RA at which the sound from unit a reaches 8 meters behind the bass group should be: if 0 degrees +45 degrees (2.5 ms delay caused by 0.86 m difference in acoustic distance between units) is 45 degrees, the phase Φ RB at which the sound emitted from the B unit reaches the next 8 m should be: 180 degrees (reverse polarity connection) +45 degrees (phase shift generated by the six-order general bass speaker unit) — 225 degrees, 225-45 degrees-180 degrees, the two sounds are 180 degrees out of phase, and the sound level after the two sounds are mixed is ∞.

2. At 80HZ, the phase Φ RA at which the sound from unit a reaches 8 meters behind the bass group should be: if 0 degrees +72 degrees (delay 2.5 ms caused by 0.86 m difference in acoustic distance between units) is 72 degrees, the phase Φ RB at which the sound emitted by the B unit reaches the next 8 m should be: 180 degrees +72 degrees (the phase shift generated by the six-order general bass loudspeaker unit) is 252 degrees, 252 degrees-72 degrees is 180 degrees, the phases of the two sounds are 180 degrees, and the sound level after the two sounds are mixed is- ∞.

3. At 100HZ, the phase Φ RA at which the sound from unit a reaches 8 meters behind the bass group should be: when the 0 degree +90 degree (2.5 ms delay caused by 0.86 m difference in acoustic distance between units) is 90 degree, the phase Φ RB at which the sound emitted from the B unit reaches the next 8 m should be: 180 degrees +90 degrees (the phase shift generated by the six-order general bass loudspeaker unit) is 270 degrees, 270 degrees-90 degrees is 180 degrees, the phases of the two sounds are 180 degrees, and the sound level after the two sounds are mixed is- ∞.

The following is a list of calculation results of the previously described calculation examples at the respective frequencies

At each of the above frequencies, the waveforms of the sounds emitted from the a unit and the B unit at 8 meters before and after the bass box and the waveforms after the sounds are mixed are shown in fig. 2 to 11.

The method for calculating the sound intensity after mixing the sounds emitted by the unit A and the unit B is as follows:

the conversion formula of the phase and the time delay is as follows: phase angle time 360 the same delay is different for different frequencies and phase angles, for example: the phase angle of 2.5 milliseconds for 50HZ is: 50 x 0.0025 x 360 x 45 degrees, the phase angle for 2.5 milliseconds for 80HZ is: 80 × 0.0025 × 360 × 72 degrees, the phase angle of 2.5 milliseconds for 100HZ is: 100 x 0.0025 x 360 x 90 degrees.

Two audio signals of the same level or sounds of the same sound pressure are mixed with each other, and a phase angle difference between them may cause superposition or cancellation, and the calculation formula is:

DB ═ 10 (LOG (0.0000000001+2 (1+ COS (RADIANS)))),

for example: phase difference of 0 degree, DB number of sound pressure increase is: 10 LOG (0.0000000001+2 (1+ COS4.71) — 6.02DB, phase difference of 180 degrees, DB number of sound pressure increase of 10 LOG (0.0000000001+2 (1+ COS3.14) — infinity DB), phase difference of 270 degrees, DB number of sound pressure increase of 10 LOG (0.0000000001+2 (1+ COS4.71) — 3.01 DB), phase difference of 360 degrees, DB number of sound pressure increase of 10 LOG (0.0000000001+2 (1+ COS6.28) — 6 DB), phase difference of 324 degrees, DB number of sound pressure increase of 10 LOG (0.00000000000001 +2 (1+ COS5.65) — 5.58 DB.

Fig. 12 is a frequency response diagram of 8 meters before and after a bass sound box for realizing heart-shaped directional radiation, which is simulated by using the sense FOCUS 3 acoustic simulation software, and it can be seen from the diagram that the average sound pressure difference of the bass frequency bands at the same distance before and after can reach more than 20dB, thereby effectively realizing the directional control of bass. Fig. 13 is a schematic view of sound wave radiation at 100Hz of a bass sound box for realizing heart-shaped directional radiation provided by the present invention simulated by using ear FOCUS 3 acoustic simulation software, and it can be seen from the figure that the sound wave radiation of the bass sound box provided by the present invention is heart-shaped.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. A bass loudspeaker box for realizing heart-shaped directional radiation comprises a shell and is characterized by further comprising a direct-phase-inversion type bass loudspeaker unit and a six-order band-pass type bass loudspeaker unit which are arranged in the shell, wherein the direct-phase-inversion type bass loudspeaker unit is positioned in front of the six-order band-pass type bass loudspeaker unit, and the directions of sound source radiation openings of the direct-phase-inversion type bass loudspeaker unit and the six-order band-pass type bass loudspeaker unit are opposite; an acoustic distance between the sound source radiation port of the direct phase reversal woofer unit and the sound source radiation port of the sixth-order band-pass woofer unit is equal to 1/4 wavelengths of a front cavity tuning frequency of the sixth-order band-pass woofer unit; the direct-wave and reverse-wave bass loudspeaker unit is connected with the six-stage band-pass bass loudspeaker unit in a reverse polarity mode.

2. The bass loudspeaker of claim 1, further comprising a single channel power amplifier driver unit, wherein the direct and inverse bass speaker unit and the six-order bandpass bass speaker unit are simultaneously driven by the single channel power amplifier driver unit.

3. The bass loudspeaker of claim 2, wherein the direct and inverse bass loudspeaker unit and the six-stage bandpass loudspeaker unit are connected in parallel with each other in an inverse polarity manner, and the single-channel power amplifier driving unit is electrically connected to the direct and inverse bass loudspeaker unit and the six-stage bandpass loudspeaker unit, respectively.

4. The woofer of claim 2 that realizes cardioid directional radiation wherein the direct and inverse woofer unit is in inverse polarity series with the sixth-order band-pass woofer unit, the single channel power amplifier drive unit is electrically connected to the direct and inverse woofer unit and the direct and inverse woofer unit is connected to the sixth-order band-pass woofer unit, or the single channel power amplifier drive unit is electrically connected to the sixth-order band-pass woofer unit and the sixth-order band-pass woofer unit is connected to the direct and inverse woofer unit.

5. The bass loudspeaker of claim 1, wherein there are two of the direct phase reversal woofer units.

6. The bass loudspeaker of claim 5, wherein there are two of the six-step bandpass woofer units.