Low-howling microphone

Abstract

A low-howling microphone relates to the technical field of audio instruments and comprises a shell and a sound pick-up, a first sound insulation plate and a second sound insulation plate are arranged in an inner cavity of the shell, the inner cavity of the shell is divided into three cavities by the first sound insulation plate and the second sound insulation plate, and the three cavities are a sound pick-up cavity, a first tuning cavity and a second tuning cavity respectively. Wherein the pickup cavity and the first tuning cavity are separated by a first sound insulation plate, and the first tuning cavity and the second tuning cavity are separated by a second sound insulation plate; the pickup is mounted in the pickup cavity, and a pickup hole is formed in the bottom of the pickup cavity; a first tuning hole is formed in the first sound insulation plate, first tuning paper is arranged on the first sound insulation plate, and the first tuning hole is covered with the first tuning paper; a plurality of second tuning holes are formed in the second sound insulation plate, a plurality of pieces of second tuning paper are arranged on the second sound insulation plate, and the second tuning holes are covered with the second tuning paper respectively.

Description

Technical Field

[0001] The present invention relates to the technical field of audio equipment, and in particular to the technology of a low-howling microphone. Background Art

[0002] A microphone is an energy conversion device that converts sound signals into electrical signals. When a microphone is used in a small space, the sound from the sound source is picked up by the pickup and then transmitted to the speaker, which then outputs the sound. However, the sound waves output by the speaker are reflected by obstacles such as the human body, the product's own structure, and walls, and are picked up again by the microphone, and then transmitted to the speaker by the microphone to produce sound. After multiple cycles, howling will occur, affecting the user experience. Summary of the invention

[0003] In view of the defects existing in the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a low-howling microphone which can effectively avoid howling.

[0004] In order to solve the above technical problems, the present invention provides a low-howling microphone, including a housing and a pickup, characterized in that:

[0005] A first sound insulation board and a second sound insulation board are provided in the inner cavity of the shell, and the inner cavity of the shell is divided into three chambers by the first sound insulation board and the second sound insulation board, and the three chambers are respectively a sound pickup chamber, a first tuning chamber and a second tuning chamber, wherein the sound pickup chamber and the first tuning chamber are separated by the first sound insulation board, and the first tuning chamber and the second tuning chamber are separated by the second sound insulation board; the pickup is installed in the sound pickup chamber, and a sound pickup hole is provided at the bottom of the sound pickup chamber; a first tuning hole is provided on the first sound insulation board, and a first tuning paper is provided on the first sound insulation board, and the first tuning paper covers the first tuning hole; a plurality of second tuning holes are provided on the second sound insulation board, and a plurality of second tuning papers are provided on the second sound insulation board, and each second tuning paper covers each second tuning hole respectively.

[0006] The low-howling microphone provided by the present invention uses a sound insulation board to divide the inner cavity of the microphone into three chambers, one of which forms a Helmholtz cavity. The resonance peak formed by the Helmholtz cavity can offset the howling resonance peak, thereby effectively preventing the microphone from generating howling. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is an exploded view of the structure of a low-howling microphone according to an embodiment of the present invention;

[0008] Figure 2 is a front view cutaway diagram of a low-howling microphone according to an embodiment of the present invention;

[0009] Figure 3 4 is an analog diagram of an equivalent circuit of a low-howling microphone according to an embodiment of the present invention. DETAILED DESCRIPTION

[0010] The following is a further detailed description of an embodiment of the present invention in conjunction with the accompanying drawings, but this embodiment is not intended to limit the present invention. All similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The commas in the present invention all represent the relationship of and.

[0011] like Figure 1-Figure 2 As shown, a low-howling microphone provided by an embodiment of the present invention comprises a housing and a pickup 3, wherein the housing is composed of an upper housing 11 and a lower housing 12;

[0012] A first sound insulation board 21 and a second sound insulation board 22 are provided in the inner cavity of the shell, and the inner cavity of the shell is divided into three chambers by the first sound insulation board 21 and the second sound insulation board 22, and the three chambers are respectively a sound pickup chamber 4, a first tuning chamber 5 and a second tuning chamber 6, wherein the sound pickup chamber 4 and the first tuning chamber 5 are separated by the first sound insulation board 21, and the first tuning chamber 5 and the second tuning chamber 6 are separated by the second sound insulation board 22; the pickup 3 is installed in the sound pickup chamber 4, and a sound pickup hole 41 is provided at the bottom of the sound pickup chamber 4; a first tuning hole 211 is provided on the first sound insulation board 21, and a first tuning paper 212 is provided on the first sound insulation board 21, and the first tuning paper 212 covers the first tuning hole 211; a plurality of second tuning holes 221 are provided on the second sound insulation board 22, and a plurality of second tuning papers 222 are provided on the second sound insulation board 22, and each second tuning paper 222 covers each second tuning hole 221 respectively.

[0013] In the embodiment of the present invention, the number of the second tuning holes 221 and the number of the second tuning papers 222 are both two. In other embodiments of the present invention, the number of the second tuning holes and the second tuning papers may be more than two.

[0014] The working principle of the embodiment of the present invention is as follows:

[0015] The acoustic volume of the pickup cavity 4 is defined as C a1 , the sound quality of the sound pickup hole 41 is defined as M a1 , the acoustic resistance of the sound pickup hole 41 is defined as R a1 ;

[0016] The acoustic capacity of the first tuning cavity 5 is defined as C a2 , the sound quality of the first tuning hole 211 is defined as M a2 The acoustic resistance of the first tuning hole 211 is defined as R a2 ;

[0017] The acoustic capacity of the second tuning cavity 6 is defined as C a3 The sum of the sound masses of the second tuning holes 221 is defined as M a3 The sum of the acoustic resistances of the second tuning holes 221 is defined as Ra3 ;

[0018] The pressure of the sound wave input to the microphone through the pickup hole is defined as F:

[0019] F=P a ×S

[0020] Where P a is the sound pressure of the sound wave input to the microphone through the pickup hole, S is the flow area of ​​the pickup hole;

[0021] According to the structure of the microphone, it can be concluded Figure 3 The microphone equivalent circuit analogy diagram and the microphone's acoustic capacitance C are shown. a , sound quality M a Harmonic resistance R a :

[0022] C a =C a1 +C a2 +C a3

[0023]

[0024]

[0025] The acoustic impedance of the microphone is:

[0026] Z a =R′ a +jX′ a

[0027]

[0028]

[0029]

[0030]

[0031] In the formula, Z a is the acoustic impedance of the sound wave input into the sound chamber through the sound pickup hole, R' a is the acoustic impedance of the sound wave input into the sound pickup cavity through the sound pickup hole, jX' a V is the acoustic impedance of the sound wave input into the sound chamber through the sound pickup hole. a is the vibration amplitude of the sound wave input into the pickup cavity through the pickup hole, f is the center frequency of the sound wave input into the pickup cavity through the pickup hole, ω is the angular frequency of the pickup cavity when it vibrates, and ω1 is the angular frequency of the first tuning cavity when it vibrates.

[0032] The sound wave is transmitted into the pickup cavity 4 through the pickup hole 41, and then transmitted into the first tuning cavity 5 through the first tuning hole 211 and the first tuning paper 212, and then transmitted into the second tuning cavity 6 through each second tuning hole 221 and each second tuning paper 222, wherein the first tuning cavity 5 forms a damping space, and the second tuning cavity 6 forms a Helmholtz cavity.

[0033] Due to the effect of the Helmholtz cavity, after the sound enters the pickup cavity 4, the air pressure in the pickup cavity 4 rises instantly and then drops instantly, forming a resonance peak. The center frequency of the resonance peak can be adjusted by adjusting the volume of the pickup cavity 4, and the height and width of the resonance peak can be adjusted by adjusting the volume of the first tuning cavity 5, the number of tuning holes and the thickness (specifications) of the tuning paper. When designing a microphone, selecting appropriate volumes of the pickup cavity 4 and the first tuning cavity 5 can enable the resonance peak formed by the Helmholtz cavity to offset the howling resonance peak formed during the voice transmission process. Finally, the low howling sound wave is transmitted to the speaker (not shown) through the pickup 3.

Claims

1. A low-howling microphone, comprising a housing and a pickup (3), characterized in that: A first sound insulation board (21) and a second sound insulation board (22) are provided in the inner cavity of the shell. The inner cavity of the shell is divided into three chambers by the first sound insulation board (21) and the second sound insulation board (22). The three chambers are respectively a sound pickup chamber (4), a first sound tuning chamber (5) and a second sound tuning chamber (6). The sound pickup chamber (4) and the first sound tuning chamber (5) are separated by the first sound insulation board (21), and the first sound tuning chamber (5) and the second sound tuning chamber (6) are separated by the second sound insulation board (22). The pickup (3) is installed in the sound pickup chamber (4). A sound pickup hole (41) is provided at the bottom of the cavity (4); a first tuning hole (211) is provided on the first sound insulation board (21), and a first tuning paper (212) is provided on the first sound insulation board (21), and the first tuning paper (212) covers the first tuning hole (211); a plurality of second tuning holes (221) are provided on the second sound insulation board (22), and a plurality of second tuning papers (222) are provided on the second sound insulation board (22), and each second tuning paper (222) covers each second tuning hole (221).

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