Small-size sound-absorbing box

Abstract

The utility model discloses a small size sound attenuation box including box, pickup, sound absorption sharp wedge and diffuser, the box is equipped with the mounting plate, and the mounting plate is equipped with the installation mouth that communicates the inside of box, the pickup is installed in the box and is opposite the installation mouth, the sound absorption sharp wedge is equipped in the inside wall of box, the diffuser is equipped in the inside wall of mounting plate, and the diffusion surface of diffuser faces the installation mouth, and the diffusion surface is evenly distributed with a plurality of convex, through the diffuser with the evenly distributed plurality of convex is directly set in the inside wall of mounting plate and makes its diffusion surface opposite the installation mouth, the loudspeaker is put into the box, and the low frequency sound wave of radiation is just the diffuse reflection of convex structure, destroys the mirror surface reflection condition that small size box parallel wall surface forms, weakens standing wave, sound absorption sharp wedge covers the inside wall of box simultaneously, and the outside noise and residual reflection sound are absorbed, realize low frequency standing wave suppression and wide frequency sound absorption in limited volume, eliminate the sound pressure level fluctuation caused by standing wave peak and valley, guarantee the accuracy of data.

Description

Technical Field

[0001] This utility model relates to the field of electroacoustic device testing equipment, and in particular to a small-sized silencer box. Background Technology

[0002] Speaker testing requires a quiet environment. An anechoic chamber is a sealed enclosure lined with sound-absorbing material to isolate external noise, providing a low-noise environment similar to an anechoic chamber for testing. During testing, the speaker under test is fixed in a preset position within the chamber, and test sounds are played. A measuring microphone inside the chamber collects sound pressure and distortion data, allowing for a quick determination of product quality. However, existing small-sized anechoic chambers have limited internal space, resulting in poor sound absorption and a tendency to generate significant standing waves, affecting the accuracy of low-frequency sound effect test results. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a small-sized anechoic chamber to solve the problem that the poor sound absorption effect and the generation of standing waves in the existing small-sized anechoic chamber affect the accuracy of low-frequency sound effect test results.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a small-sized silencer box, including... The housing is provided with a mounting plate, and the mounting plate has a mounting port that communicates with the interior of the housing. A microphone is installed inside the enclosure and directly opposite the mounting port; Sound-absorbing wedges are provided on the inner side wall of the enclosure; A diffuser is disposed on the inner sidewall of the mounting plate, with the diffusion surface of the diffuser facing the mounting port, and multiple protrusions evenly distributed on the diffusion surface.

[0005] Furthermore, the number of diffusers is multiple.

[0006] Furthermore, the plurality of diffusers are equidistantly distributed around the central axis of the pickup.

[0007] Furthermore, the box body is a regular hexahedron, and the number of diffusers is four, all of which are fan-shaped.

[0008] Furthermore, the sound-absorbing wedge is made of high-density sound-absorbing cotton.

[0009] Furthermore, an elastic vibration isolation layer is provided between the mounting plate and the diffuser.

[0010] Furthermore, each inner wall of the enclosure is provided with the sound-absorbing wedge.

[0011] Furthermore, the tips of the sound-absorbing wedges on two adjacent inner sidewalls of the enclosure are orthogonal to each other.

[0012] Furthermore, the cross-sectional shape of the protrusion is semi-circular.

[0013] Furthermore, the sound-absorbing wedge includes a connected base and a pointed tip, the base being connected to the inner sidewall of the enclosure.

[0014] The beneficial effects of this utility model are as follows: The small-sized anechoic chamber provided by this utility model directly sets a diffuser with multiple evenly distributed protrusions on the inner wall of the mounting plate, with its diffuser surface facing the mounting opening. Once the speaker is placed in the chamber, the radiated low-frequency sound waves are diffusely reflected by the protruding structure, which destroys the specular reflection conditions formed by the parallel wall surface of the small-sized chamber and weakens the standing waves. At the same time, the sound-absorbing wedges cover the inner wall of the chamber and absorb external noise and residual reflected sound. Thus, low-frequency standing wave suppression and wideband sound absorption are achieved simultaneously within a limited volume, eliminating sound pressure level fluctuations caused by standing wave peaks and valleys, ensuring the accuracy of sound pressure and distortion data collected by the microphone, and solving the problems of poor sound absorption, severe standing waves, and distortion of low-frequency test results in existing small-sized anechoic chambers. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of the small-sized silencer box according to Embodiment 1 of this utility model; Figure 2 This is an exploded view of the small-sized silencer box according to Embodiment 1 of this utility model; Figure 3 This is a schematic cross-sectional view of the small-sized silencer box according to Embodiment 1 of this utility model; Figure 4 This is a schematic diagram of the structure of the diffuser in Embodiment 1 of this utility model; Figure 5 This is a schematic diagram of the sound-absorbing wedge structure of Embodiment 1 of this utility model; Figure 6 This is a cross-sectional structural diagram of the small-sized silencer box in Embodiment 2 of this utility model.

[0016] Label Explanation: 1. Enclosure; 11. Mounting plate; 12. Mounting port; 2. Pickup; 3. Sound-absorbing wedge; 31. Base; 32. Tip; 4. Diffuser; 41. Protrusion; 5. Elastic vibration isolation layer. Detailed Implementation

[0017] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0018] Please refer to Figure 1A small-sized silencer box includes a box body 1, a microphone 2, a sound-absorbing wedge 3, and a diffuser 4. The box body 1 is provided with a mounting plate 11, and the mounting plate 11 is provided with a mounting port 12 communicating with the interior of the box body 1. The microphone 2 is installed inside the box body 1 and faces the mounting port 12. The sound-absorbing wedge 3 is provided on the inner side wall of the box body 1. The diffuser 4 is provided on the inner side wall of the mounting plate 11, and the diffusion surface of the diffuser 4 faces the mounting port 12, and the diffusion surface is evenly distributed with a plurality of protrusions 41.

[0019] As can be seen from the above description, the beneficial effects of this utility model are as follows: by directly setting the diffuser 4 with a plurality of evenly distributed protrusions 41 on the inner sidewall of the mounting plate 11 and making its diffusion surface face the mounting port 12, once the speaker is placed in the box, the radiated low-frequency sound waves are diffusely reflected by the protrusion 41 structure, which destroys the mirror reflection conditions formed by the parallel wall surface of the small-sized box 1 and weakens the standing waves; at the same time, the sound-absorbing wedge 3 covers the inner sidewall of the box 1 to absorb external noise and residual reflected sound, thereby simultaneously achieving low-frequency standing wave suppression and wideband sound absorption within a limited volume, eliminating sound pressure level fluctuations caused by standing wave peaks and valleys, ensuring the accuracy of the sound pressure and distortion data collected by the pickup 2, and solving the problems of poor sound absorption, severe standing waves, and distortion of low-frequency test results in existing small-sized anechoic chambers.

[0020] Please combine Figure 2 Furthermore, the number of diffusers 4 is multiple.

[0021] As can be seen from the above description, setting the number of diffusers 4 to multiple can form multi-directional scattering paths, further disrupting the coherent superposition of a single direction, dispersing the standing wave energy, and making the sound field distribution inside the box 1 more uniform.

[0022] Please combine Figure 2 and Figure 3 Furthermore, the plurality of diffusers 4 are equidistantly distributed around the central axis of the pickup 2.

[0023] As described above, multiple diffusers 4 are equiangularly distributed around the central axis of the pickup 2, forming a rotationally symmetric scattering pattern. This reduces the sound pressure variation caused by the speaker's off-axis installation and improves the consistency of tests across different batches.

[0024] Please combine Figure 2 and Figure 4 Furthermore, the box 1 is a regular hexahedron, and there are four diffusers 4, all of which are fan-shaped.

[0025] As can be seen from the above description, the enclosure 1 is a regular hexahedron and uses four fan-shaped diffusers 4, which can utilize the diagonal space to arrange the maximum diffusion area. The fan-shaped outline matches the corner area, which saves internal space and maintains symmetrical scattering, avoiding local sound pressure concentration.

[0026] Furthermore, the sound-absorbing wedge 3 is made of high-density sound-absorbing cotton.

[0027] As described above, high-density sound-absorbing cotton, as a wedge material, has a characteristic impedance close to that of air, which can efficiently inject sound energy and convert it into heat, reduce multiple reflections in the mid-to-low frequency range, and lower the background noise inside the enclosure.

[0028] Please combine Figure 6 Furthermore, an elastic vibration isolation layer 5 is provided between the mounting plate 11 and the diffuser 4.

[0029] As described above, an elastic vibration isolation layer 5 is provided between the mounting plate 11 and the diffuser 4 to block the transmission of speaker vibration to the solid wall of the enclosure, suppress structural sound radiation, and avoid interference of vibration modes with sound pressure testing.

[0030] Please combine Figure 2 and Figure 3 Furthermore, each inner sidewall of the enclosure 1 is provided with the sound-absorbing wedge 3.

[0031] As described above, all inner walls of the enclosure 1 are equipped with sound-absorbing wedges 3 to eliminate exposed reflective surfaces, form continuous sound-absorbing boundaries, enhance overall sound insulation and sound absorption capabilities, and prevent external noise transmission and multiple internal reflections.

[0032] Please combine Figure 2 and Figure 3 Furthermore, the tips of the sound-absorbing wedges 3 on the two adjacent inner sidewalls of the housing 1 are orthogonal to each other.

[0033] As described above, the wedge tips of adjacent walls are orthogonal to each other, cutting off the mirror reflection paths of three pairs of parallel walls, disrupting the conditions for establishing axial standing waves, and making the peak-valley distribution of the low-frequency sound field tend to be flat.

[0034] Please combine Figure 4 Furthermore, the cross-sectional shape of the protrusion 41 is semi-circular.

[0035] As described above, the cross-section of protrusion 41 adopts a semi-circular profile with continuous surface curvature and no sharp edges. It can maintain smooth scattering within a large incident angle range, reduce directional fluctuations caused by edge diffraction, and improve diffusion uniformity.

[0036] Please combine Figure 3 and Figure 5 Furthermore, the sound-absorbing wedge 3 includes a connected base 31 and a pointed tip 32, wherein the base 31 is connected to the inner sidewall of the housing 1.

[0037] As described above, the wedge consists of two parts: a base 31 and a tip 32. The base 31 is thick and the tip is thin, forming a gradually changing impedance interface. This allows sound waves to gradually enter the high-loss material from the air, reducing interface reflection and expanding the low-frequency sound absorption range. At the same time, the base 31 provides sufficient rigidity to support the stability of the tip shape.

[0038] Embodiment 1 of this utility model is as follows: Please refer to Figure 1 A small-sized anechoic chamber is suitable for loudspeaker acoustic testing scenarios that are sensitive to space, tempo, and cost, such as the end of a production line, a laboratory, or a repair shop. It can provide a test space with low standing waves and low background noise for miniature loudspeakers, receivers, and headphone drivers with a diameter of less than 150mm without building a full-size anechoic chamber, meeting the needs for rapid online detection and quality judgment of sound pressure level, frequency response, and distortion.

[0039] Specifically, the small-sized silencer box includes a housing 1, a microphone 2, a sound-absorbing wedge 3, and a diffuser 4. The housing 1 is provided with a mounting plate 11, which has a mounting opening 12 communicating with the interior of the housing 1. The microphone 2 is installed inside the housing 1 and faces the mounting opening 12. The sound-absorbing wedge 3 is located on the inner sidewall of the housing 1. The diffuser 4 is located on the inner sidewall of the mounting plate 11, with its diffusion surface facing the mounting opening 12, and the diffusion surface is evenly distributed with multiple protrusions 41. It can be understood that by directly mounting the diffuser 4 with the evenly distributed multiple protrusions 41 on the mounting plate 11... The inner wall is aligned with the mounting port 12. Once the speaker is placed inside the enclosure, the radiated low-frequency sound waves are diffusely reflected by the protrusion 41 structure, which disrupts the mirror reflection conditions formed by the parallel wall of the small-sized enclosure 1 and weakens the standing waves. At the same time, the sound-absorbing wedge 3 covers the inner wall of the enclosure 1 to absorb external noise and residual reflected sound. Thus, low-frequency standing wave suppression and wideband sound absorption are achieved simultaneously within a limited volume, eliminating sound pressure level fluctuations caused by standing wave peaks and valleys, ensuring the accuracy of sound pressure and distortion data collected by the pickup 2, and solving the problems of poor sound absorption, severe standing waves, and distortion of low-frequency test results in existing small-sized anechoic chambers.

[0040] More specifically, in the actual testing process, the miniature speaker to be tested is mounted on a test fixture, which is provided with a sound output channel that simulates the installation environment of the miniature speaker. By installing the test fixture at the mounting port 12 of the mounting plate 11 and connecting the sound output channel with the inside of the enclosure 1, the miniature speaker is activated and the sound of the miniature speaker is collected by the microphone 2.

[0041] Please combine Figure 2 , Figure 3 and Figure 4In this embodiment, the number of diffusers 4 is multiple, thus forming multi-directional scattering paths, further disrupting the coherent superposition in a single direction, dispersing the standing wave energy, and making the sound field distribution within the enclosure 1 more uniform. Specifically, the multiple diffusers 4 are equiangularly distributed around the central axis of the pickup 2, thus forming a rotationally symmetric scattering pattern, reducing sound pressure changes caused by off-axis installation of the loudspeaker, and improving the consistency of tests across different batches. More specifically, the enclosure 1 is a regular hexahedron (e.g., Figure 2 As shown), there are four diffusers 4, and the shape of each of the four diffusers 4 is fan-shaped (as shown). Figure 4 As shown in the image, the enclosure 1 is a regular hexahedron with four fan-shaped diffusers 4. This allows for maximum diffusion area utilization by arranging diagonal spaces. The fan-shaped outlines match the corner areas, saving internal space while maintaining symmetrical scattering and avoiding localized sound pressure concentration. For more details, please refer to [the image / document / reference]. Figure 4 The cross-sectional shape of the protrusion 41 is semi-circular. The surface curvature of the semi-circular contour is continuous and there are no sharp edges. It can maintain smooth scattering within a large incident angle range, reduce directional fluctuations caused by edge diffraction, and improve diffusion uniformity.

[0042] In addition, in some other embodiments, the number of diffusers 4 may be one, the shape of diffusers 4 may be semi-circular, semi-elliptical, etc., and the shape of the box 1 may be other polyhedra, which will not be described in detail here.

[0043] Please combine Figure 3 and Figure 5 The sound-absorbing wedge 3 includes a connected base 31 and a pointed tip 32. The base 31 is connected to the inner wall of the housing 1. The wedge is composed of two sections: the base 31 and the pointed tip 32. The base 31 is thick and the pointed tip is thin, forming an impedance gradient interface, which allows sound waves to gradually enter the high-loss material from the air, reducing interface reflection and expanding the low-frequency sound absorption range. At the same time, the base 31 provides sufficient rigidity to support the stability of the pointed tip shape.

[0044] Specifically, in this embodiment, the base 31 and the tip 32 have the same material density. The sound-absorbing wedge 3 is a one-piece structure, and the material of the sound-absorbing wedge 3 is high-density sound-absorbing cotton. As a wedge material, high-density sound-absorbing cotton has a characteristic impedance close to that of air, which can efficiently inject sound energy and convert it into heat, reduce multiple reflections at mid- and low frequencies, and reduce the background noise inside the enclosure. Specifically, the high-density sound-absorbing cotton has a surface density of not less than 0.8 kg / m³. 2 Sound-absorbing cotton.

[0045] In other embodiments, the base 31 and the tip 32 may have different material densities. Specifically, the base 31 may be made of high-density glass wool (80-100 kg / m³). 3To provide high acoustic impedance, the tip 32 may be made of low-density glass wool (30-40 kg / m²). 3 Maintaining a gradual transition allows for a reduction in overall volume while ensuring sound absorption.

[0046] Please combine Figure 2 and Figure 3 Each inner wall of the enclosure 1 is provided with a sound-absorbing wedge 3, which reduces the exposure of the reflective surface, forms a continuous sound-absorbing boundary, enhances the overall sound insulation and sound absorption capacity, and prevents external noise transmission and multiple internal reflections. Specifically, the tips of the sound-absorbing wedges 3 on two adjacent inner walls of the enclosure 1 are orthogonal to each other, which can cut off the mirror reflection path of three pairs of parallel walls, destroy the conditions for the establishment of axial standing waves, and make the peak and valley distribution of the low-frequency sound field tend to be flat.

[0047] Please refer to Figure 6 The second embodiment of this utility model is a further improvement on the first embodiment. In this second embodiment, an elastic vibration isolation layer 5 is provided between the mounting plate 11 and the diffuser 4. The elastic vibration isolation layer 5 is used to block the transmission of speaker vibration to the solid wall of the enclosure, suppress structural sound radiation, and avoid interference of vibration mode on sound pressure test.

[0048] Specifically, the elastic vibration isolation layer 5 can be made of materials such as natural rubber, nitrile rubber, neoprene rubber, polyurethane elastomer, mixed-cell polyurethane foam, microporous EPDM, TPE or fabric-reinforced rubber pads, and can be used alone or in combination depending on the load-bearing capacity, thickness and environmental requirements.

[0049] In summary, the small-sized anechoic chamber provided by this utility model directly sets a diffuser with multiple evenly distributed protrusions on the inner wall of the mounting plate, with its diffusion surface facing the mounting opening. Once the speaker is placed inside the chamber, the radiated low-frequency sound waves are diffusely reflected by the protruding structure, disrupting the specular reflection conditions formed by the parallel walls of the small-sized chamber and weakening the standing waves. At the same time, the sound-absorbing wedges covering the inner wall of the chamber absorb external noise and residual reflected sound, thereby simultaneously achieving low-frequency standing wave suppression and wideband sound absorption within a limited volume. This eliminates sound pressure level fluctuations caused by standing wave peaks and valleys, ensuring the accuracy of sound pressure and distortion data collected by the microphone, and solving the problems of poor sound absorption, severe standing waves, and distorted low-frequency test results in existing small-sized anechoic chambers.

[0050] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A small-sized silencer box, characterized in that, include The housing is provided with a mounting plate, and the mounting plate has a mounting port that communicates with the interior of the housing. A microphone is installed inside the enclosure and directly opposite the mounting port; Sound-absorbing wedges are provided on the inner side wall of the enclosure; A diffuser is disposed on the inner sidewall of the mounting plate, with the diffusion surface of the diffuser facing the mounting port, and multiple protrusions evenly distributed on the diffusion surface.

2. The small-sized silencer box according to claim 1, characterized in that, The number of diffusers is multiple.

3. The small-sized silencer box according to claim 2, characterized in that, The multiple diffusers are equidistantly distributed around the central axis of the microphone.

4. The small-sized silencer box according to claim 2, characterized in that, The box is a regular hexahedron, and there are four diffusers, each of which is fan-shaped.

5. The small-sized silencer box according to claim 1, characterized in that, The sound-absorbing wedge is made of high-density sound-absorbing cotton.

6. The small-sized silencer according to claim 1, characterized in that, An elastic vibration isolation layer is provided between the mounting plate and the diffuser.

7. The small-sized silencer according to claim 1, characterized in that, Each inner wall of the enclosure is provided with the sound-absorbing wedge.

8. The small-sized silencer box according to claim 7, characterized in that, The tips of the sound-absorbing wedges on the two adjacent inner sidewalls of the enclosure are orthogonal to each other.

9. The small-sized silencer box according to claim 1, characterized in that, The cross-sectional shape of the protrusion is semi-circular.

10. The small-sized silencer according to claim 1, characterized in that, The sound-absorbing wedge includes a connected base and a pointed tip, the base being connected to the inner wall of the enclosure.

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