sound box

Abstract

The application belongs to the field of sound boxes and relates to a sound box. The sound box comprises a sound box body and an acoustic superstructure unit. The sound box body comprises a box body and a loudspeaker. A resonance cavity is formed in the box body. An installation hole is formed in the box body and communicates with the resonance cavity. The loudspeaker is installed at the installation hole to block the installation hole and close the resonance cavity. The acoustic superstructure unit forms a back cavity. A through hole is formed in the acoustic superstructure unit and communicates with the back cavity and the resonance cavity. The through hole of the acoustic superstructure unit is adjacent to an antinode position of a standing wave that causes abnormal peaks or abnormal valleys, and is used for smoothing the abnormal peaks or abnormal valleys caused by the standing wave. The sound box can reduce the negative influence of the standing wave of the sound box without increasing the volume of the sound box.

Description

Technical Field

[0001] This invention belongs to the field of speaker technology, and in particular relates to a speaker capable of smoothing the peak or valley values ​​of standing waves. Background Technology

[0002] Standing waves typically exist within the resonant cavity of a speaker enclosure. These waves can cause sound pressure levels to increase or decrease at certain frequencies, preventing the speaker from reproducing sound smoothly and evenly at those frequencies. Strong standing waves can create peaks and troughs, making the sound, which should be smooth, sound muddy or humming, affecting the expressiveness of musical details and thus reducing the speaker's sound quality. Therefore, minimizing the negative impact of standing waves is of great importance.

[0003] Existing technologies for reducing the negative impact of speaker standing waves include optimizing speaker cabinet manufacturing and lining the interior of the cabinet with sound-absorbing materials. Speaker cabinet manufacturing optimization includes avoiding integer multiples between the internal dimensions of the cabinet and the wavelength of low-frequency sound waves, using non-parallel walls and complex internal structures, and manufacturing speaker systems with bass reflex ports or passive radiators. However, these optimization techniques increase the complexity of speaker manufacturing, making tuning more difficult, and typically increase the speaker's size, affecting its aesthetics. Lining the interior of the cabinet with sound-absorbing materials increases the speaker's weight and size, affecting its low-frequency response and the long-term stability of its sound quality. Summary of the Invention

[0004] The purpose of this invention is to provide a speaker that addresses the problem that existing technologies for reducing the negative effects of speaker standing waves typically increase the speaker's size.

[0005] To solve the above-mentioned technical problems, on the one hand, the present invention provides a speaker, including a speaker body and an acoustic superstructure unit. The speaker body includes a cabinet and a speaker. A resonant cavity is formed in the cabinet. A mounting hole communicating with the resonant cavity is opened on the cabinet. The speaker is installed at the mounting hole to block the mounting hole, thereby sealing the resonant cavity.

[0006] The acoustic superstructure unit has a back cavity, and the acoustic superstructure unit has a through hole communicating with the back cavity. The through hole is also communicating with the resonant cavity. The through hole of the acoustic superstructure unit is adjacent to the antinode of the standing wave that causes abnormal peak or abnormal valley values, and is used to smooth the abnormal peak or abnormal valley values ​​caused by the standing wave.

[0007] According to an embodiment of the present invention, when a standing wave in the resonant cavity of the speaker body causes abnormal peaks or valleys in the speaker's sensitivity, an acoustic superstructure composed of at least one acoustic superstructure unit can be provided within the resonant cavity. The through-holes of the acoustic superstructure unit are positioned corresponding to the antinodes of the standing wave. Through the interaction between the acoustic superstructure and the resonant cavity, the abnormal peaks or valleys generated by the standing wave in the speaker body are smoothed. This speaker can reduce the negative impact of speaker standing waves without increasing the speaker's volume. Furthermore, the presence of the acoustic superstructure can also improve the stiffness of the speaker body, reducing the risk of noise generated by speaker vibration.

[0008] Optionally, there may be multiple abnormal peaks or valleys, and each abnormal peak or valley corresponds to at least one acoustic superstructure unit.

[0009] Optionally, the acoustic superstructure unit corresponding to the same abnormal peak or valley has the same size parameters.

[0010] Optionally, the first-order acoustic mode frequency of the acoustic superstructure unit is equal to the standing wave frequency that causes the corresponding abnormal peak or valley.

[0011] Optionally, the first-order acoustic mode frequency of each of the acoustic superstructure units is determined based on the size of the through-hole and the size of the back cavity.

[0012] Optionally, the acoustic superstructure unit is further provided with an extension tube, which is located in the back cavity, and one end of the extension tube is connected to the resonant cavity through the through hole, and the other end of the extension tube is connected to the back cavity.

[0013] Optionally, at least a portion of the extension tube extends in a straight line, or at least a portion of the extension tube extends in a curve.

[0014] Optionally, a partition plate is provided in the back cavity, the partition plate extends spirally in the back cavity to form a spiral channel in the back cavity, and one end of the spiral channel communicates with the through hole.

[0015] Optionally, a layered plate is also provided in the back cavity. The layered plate is arranged perpendicularly to the partition plate and divides the spiral channel into a first channel and a second channel. One end of the first channel is connected to the through hole, and the layered plate has a notch so that the other end of the first channel is connected to one end of the second channel.

[0016] Optionally, the acoustic superstructure unit and the housing are integrally formed. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the speaker provided in Embodiment 1 of the present invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of a Helmholtz resonance acoustic superstructure unit in the mid-curved back cavity;

[0019] Figure 3 yes Figure 2 Mid-section view;

[0020] Figure 4 yes Figure 2 Another cross-sectional view;

[0021] Figure 5 This is another schematic diagram of the curled-back cavity Helmholtz resonance acoustic superstructure unit provided in Embodiment 1 of the present invention;

[0022] Figure 6 This is another schematic diagram of the curled-back cavity Helmholtz resonance acoustic superstructure unit provided in Embodiment 1 of the present invention;

[0023] Figure 7 yes Figure 1 A flowchart illustrating the manufacturing process of a speaker.

[0024] Figure 8 This is a comparison chart of the sensitivity curve of the speaker provided in Embodiment 1 of the present invention and the sensitivity curve of an existing speaker;

[0025] Figure 9 This is a schematic diagram of the speaker provided in Embodiment 2 of the present invention;

[0026] Figure 10 yes Figure 9 Schematic diagram of the acoustic superstructure unit of the middle extension tube;

[0027] Figure 11 yes Figure 9 Cross-sectional view of the acoustic superstructure unit of the middle extension tube;

[0028] Figure 12 yes Figure 9 A flowchart illustrating the manufacturing process of a speaker.

[0029] Figure 13 This is another schematic diagram of the extension tube acoustic superstructure unit provided in Embodiment 2 of the present invention;

[0030] Figure 14 This is another schematic diagram of the extension tube acoustic superstructure unit provided in Embodiment 2 of the present invention;

[0031] Figure 15 This is a schematic diagram of the coiled extension tube acoustic superstructure unit provided in Embodiment 3 of the present invention;

[0032] Figure 16This is a schematic diagram of the coiled back cavity extension tube acoustic superstructure unit provided in Embodiment 4 of the present invention;

[0033] Figure 17 This is a schematic diagram of the coiled back cavity coiled extension tube acoustic superstructure unit provided in Embodiment 5 of the present invention;

[0034] Figure 18 This is a schematic diagram of the coiled back cavity perforated plate acoustic superstructure unit provided in Embodiment Six of the present invention.

[0035] The reference numerals in the accompanying drawings are as follows:

[0036] 1. Acoustic superstructure; 11. Acoustic superstructure unit; 111. Back cavity; 112. Extension tube; 113. Through hole; 114. Centerline; 115. Partition plate; 116. Layered plate;

[0037] 2. Box housing; 21. Resonance cavity;

[0038] 3. Speaker. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship between the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0042] Example 1

[0043] like Figures 1 to 4As shown, the speaker provided in this embodiment of the invention includes a speaker body and an acoustic superstructure unit 11. The speaker body includes a cabinet 2 and a speaker 3. A resonant cavity 21 is formed inside the cabinet 2. A mounting hole communicating with the resonant cavity 21 is provided on the cabinet 2. The speaker 3 is installed at the mounting hole of the cabinet 2 and the mounting hole is blocked to form a closed resonant cavity 21 inside the speaker body. A standing wave can be formed in the resonant cavity 21. The standing wave can cause abnormal peak or abnormal trough values ​​in the sensitivity of the speaker body.

[0044] Each acoustic superstructure unit 11 has a back cavity 111, and each acoustic superstructure unit 11 has a through hole 113 communicating with the back cavity 111. The through hole 113 is also communicating with the resonant cavity 21. Each acoustic superstructure unit has an adjustable first-order acoustic mode frequency.

[0045] In this resonant cavity 21, at least one acoustic superstructure unit 11 is provided at a preset position. The through hole of the at least one acoustic superstructure unit 11 is adjacent to the antinode of the standing wave that causes abnormal peak or abnormal valley values ​​in the resonant cavity 21. By adjusting the first-order acoustic mode frequency of each acoustic superstructure unit 11, the abnormal peak or abnormal valley values ​​caused by the standing wave can be smoothed.

[0046] The speaker provided in this embodiment of the invention has a standing wave formed within the resonant cavity 21 of its main body. When this standing wave causes abnormal peaks or valleys in the speaker's sensitivity, an acoustic superstructure 1, composed of at least one acoustic superstructure unit 11, can be disposed within the resonant cavity 21. The opening of the acoustic superstructure unit 11 is positioned corresponding to the antinode of the standing wave. By adjusting the first-order acoustic mode frequency of the acoustic superstructure unit 11, the interaction between the acoustic superstructure 1 and the resonant cavity 21 can be used to smooth out the abnormal values ​​or valleys generated by the standing wave in the speaker body. This speaker can reduce the negative impact of the speaker's standing wave without increasing its volume. Furthermore, the presence of the acoustic superstructure 1 can also improve the stiffness of the speaker body and reduce the risk of noise generated by speaker vibration.

[0047] In Embodiment 1, the standing wave corresponds to a standing wave frequency. By adjusting the first-order acoustic mode frequency of the acoustic superstructure unit 11 to make the first-order acoustic mode frequency of the acoustic superstructure unit 11 consistent with the standing wave frequency, it is possible to smooth out abnormal peaks or valleys in the speaker body caused by the standing wave.

[0048] In Example 1, as Figure 1 and Figure 2As shown, the acoustic superstructure unit 11 is a curled-back cavity Helmholtz resonance acoustic superstructure unit 11a, that is, a curled-back cavity 111 and a through hole 113 are formed on the acoustic superstructure unit 11. The through hole 113 connects the curled-back cavity 111 with the resonance cavity 21 of the box 2. The through hole 113 is equivalent to the opening of the back cavity 111, and Helmholtz resonance can occur in the curled-back cavity 111.

[0049] In Example 1, as Figures 2 to 4 As shown, the acoustic superstructure unit 11 has a cuboid shape and multiple right-angled corners corresponding to the curled-up back cavity 111. In other embodiments, the acoustic superstructure unit 11 may have a cylindrical shape (e.g., ...). Figure 5 The acoustic superstructure unit 11 can be any shape (as shown), and when its shape is cylindrical, the corresponding coiled back cavity smoothly transitions at the corners. Specifically, a partition plate 115 can be provided within the back cavity 111, extending spirally to form a spiral channel. One end of the spiral channel connects to the through hole 113. The spiral channel can be a square spiral channel with multiple right-angled corners, or an Archimedean spiral channel in the form of a helix. The spiral channel can form a coiled channel, thereby extending the sound propagation path within the back cavity 111 and reducing the first-order acoustic mode frequency of the acoustic superstructure unit 11.

[0050] In addition, such as Figure 6 As shown, a layered plate 116 can also be provided within the back cavity 111. The layered plate 116 is perpendicular to the partition plate 115 and divides the spiral channel into a first channel and a second channel. One end of the first channel is connected to the through hole 113, and the layered plate 116 has a notch so that the other end of the first channel is connected to the second channel. That is, multiple layers of the spiral channel can be provided in the depth direction of the back cavity 111. The layered spiral channel can form a complete channel with a longer effective length while occupying less space, thereby reducing the first-order acoustic mode frequency of the acoustic superstructure unit 11.

[0051] In Embodiment 1, the acoustic superstructure 1 and the enclosure 2 are integrally formed. Specifically, it can be manufactured by mold or by 3D printing, which makes it easy to manufacture and saves costs. It can also improve the rigidity of the speaker and reduce the risk of noise caused by the vibration of the speaker enclosure 2.

[0052] Figure 7 As shown, the speaker manufacturing method provided in Embodiment 1 of the present invention includes the following steps:

[0053] Step S1: Calculate the frequency response of the speaker body using finite element method and plot the sensitivity curve of the speaker body. Based on the sensitivity curve and frequency response results of the speaker body, determine the abnormal peak frequency f1 corresponding to the abnormal peak and the corresponding sound pressure distribution, or the abnormal valley frequency f2 corresponding to the abnormal valley and the corresponding sound pressure distribution.

[0054] Step S2: Calculate the acoustic modes of the resonant cavity 21 using finite element method, and find the standing wave frequency f0 (acoustic mode frequency) and standing wave mode (acoustic mode shape) of the resonant cavity 21 that cause the abnormal peak or abnormal valley near the abnormal peak frequency f1 or abnormal valley frequency f2.

[0055] The standing wave frequency f0 is close to the abnormal peak frequency f1 or the abnormal valley frequency f2, and the sound pressure distribution of the standing wave mode that causes the abnormal peak or abnormal valley is similar to the sound pressure distribution corresponding to the abnormal peak frequency f1 and the sound pressure distribution corresponding to the abnormal valley frequency f2.

[0056] Step S3: Adjust the distribution of the acoustic superstructure 1 in the resonant cavity 21 so that the opening of the acoustic superstructure unit 11 is set at the antinode position of the standing wave mode so that the abnormal peak or abnormal valley value can be smoothed by the acoustic superstructure unit 11.

[0057] Step S4: Adjust the structural parameters of the acoustic superstructure unit 11 so that the first-order acoustic mode frequency of the acoustic superstructure unit 11 is equal to the standing wave frequency f0.

[0058] In Embodiment 1, the first-order acoustic mode frequency of the acoustic superstructure unit 11 is calculated using the finite element method, wherein the opening of the acoustic superstructure unit 11 adopts an impedance end boundary condition.

[0059] The first-order acoustic mode frequency of each of the acoustic superstructure units 11 can be determined according to the size of the through-hole 113 and the size of the back cavity 111. Specifically, in Embodiment 1, the acoustic superstructure unit 11 adopts a coiled back cavity Helmholtz resonant acoustic superstructure unit 11a. The structural parameters of the coiled back cavity Helmholtz resonant acoustic superstructure unit 11a include the aperture d of the through-hole 113 (the peak absorption frequency increases with the increase of the aperture), the depth t of the through-hole 113 (the peak absorption frequency decreases with the increase of the depth), and the equivalent depth l of the back cavity. cavity (The peak absorption frequency decreases with increasing depth), and the dimensions of the back cavity channel 111 are w1 and w2. The equivalent depth of the back cavity is l. cavityThe length of the centerline 114 of the back cavity 111 is represented by the total depth from the first end (the end connected to the through hole 113) to the last end (the end away from the through hole 113). The channel size w1 of the back cavity 111 represents the height of the back cavity 111 along the axial direction of the through hole 113. The channel size w2 of the back cavity 111 represents the width of the back cavity 111 along the axial direction perpendicular to the through hole 113.

[0060] By adjusting the structural parameters of the coiled back cavity Helmholtz resonance acoustic superstructure unit 11a, the first-order acoustic mode frequency of the acoustic superstructure unit 11 is made equal to the standing wave frequency f0.

[0061] In Embodiment 1, when calculating the first-order acoustic mode frequency of the acoustic superstructure unit 11, an analytical method can be used to first calculate the sound absorption coefficient of the acoustic superstructure unit 11 (i.e., the coiled back cavity Helmholtz resonance acoustic superstructure unit 11a), and then extract the first sound absorption peak frequency of the sound absorption coefficient. The first sound absorption peak frequency of the sound absorption coefficient is the first-order acoustic mode frequency of the acoustic superstructure unit.

[0062] Furthermore, the calculation process for the sound absorption coefficient of the coiled back cavity Helmholtz resonant acoustic superstructure unit 11a is as follows:

[0063] (1) The acoustic impedance ratio of the single-hole perforated plate (the panel with through holes 113 on the coiled back cavity Helmholtz resonant acoustic superstructure unit 11a) is z h Satisfying the relation:

[0064]

[0065] Where, x h The acoustic resistivity ratio of a single-hole perforated plate, y h The acoustic impedance ratio of a single-hole perforated plate is represented by ; j represents the imaginary part in units; μ is the aerodynamic viscosity coefficient; σ represents the perforation rate of the single-hole perforated plate, and satisfies the relationship σ=πd. 2 / S; S represents the area of ​​the coiled back cavity Helmholtz resonant acoustic superstructure unit 11b in the direction perpendicular to the axis of the through hole 112, satisfying the relation S=ab; c0 is the speed of sound in air; parameter K satisfies the relation ω represents angular frequency.

[0066] (2) The acoustic impedance ratio of the coiled back cavity 111 to z c Satisfying the relation:

[0067] Among them, y cS' represents the acoustic impedance ratio of the coiled back cavity 111; S' represents the area of ​​the back cavity 111 of the coiled back cavity Helmholtz resonant acoustic superstructure unit 11a in the cross section perpendicular to its centerline 114, satisfying the relation S'=w1w2; k represents the wave number, and satisfies the relation k=ω / c0.

[0068] (3) The sound absorption coefficient α1 of the curled-back cavity Helmholtz resonant acoustic superstructure unit 11a satisfies the following relationship:

[0069] Step S5: Calculate the frequency response of the speaker with the acoustic superstructure 1 and plot the sensitivity curve of the speaker to determine the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker. If the smoothing effect is not good, repeat steps S3 to S5 until a satisfactory smoothing effect is obtained.

[0070] Specifically, in step S5, "determining the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker" includes:

[0071] S51. Set a threshold for the root mean square error of sensitivity, and determine the abnormal frequency band where the abnormal peak and / or valley values ​​are located. The determination of the abnormal frequency band is based on the sensitivity curve of the speaker; the significantly non-smooth frequency band located near the abnormal peak on the speaker's sensitivity curve is the abnormal frequency band.

[0072] S52. Calculate the root mean square error σ of the speaker's sensitivity curve within the abnormal frequency band. SPL .

[0073] Specifically, in step S52, the mean square deviation σ SPL Satisfying the relation:

[0074] Where N represents the number of discrete frequencies within the abnormal frequency band; SPL i μ represents the sensitivity corresponding to the i-th abnormal frequency within the abnormal frequency band. SPL This represents the average sensitivity within the abnormal frequency band, and satisfies the following relationship:

[0075] If the mean square error σ SPL If the mean square error is not higher than the threshold value of the sensitivity root mean square, then the acoustic superstructure provides a good smoothing effect on the sensitivity curve of the speaker, achieving a satisfactory smoothing effect; if the mean square error σ SPL If the value is higher than the threshold of the mean square error of the sensitivity, the acoustic superstructure will not effectively smooth the sensitivity curve of the speaker.

[0076] Step S6 involves experimentally verifying the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker. If the smoothing effect is unsatisfactory, steps S3 to S6 are repeated until a satisfactory smoothing effect is obtained.

[0077] In step S6, the detailed steps of "verifying the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker" are basically the same as the detailed steps S51-S52 of "determining the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker" in step S5. The only difference is that in step S5, the sensitivity is obtained by calculation, while in step S6, the sensitivity is obtained through experiment. These details will not be repeated here.

[0078] like Figure 8 The diagram shows a comparison between the sensitivity curve of the speaker provided in Embodiment 1 of the present invention and the sensitivity curve of an existing speaker (without acoustic superstructure). The solid line represents the sensitivity curve of the existing speaker, and the dashed line represents the sensitivity curve of the speaker provided in Embodiment 1 of the present invention. Figure 8 As can be seen, existing speakers exhibit an abnormal peak in the 2000Hz–4000Hz frequency range, while the speaker provided in Embodiment 1 of this invention can effectively smooth this abnormal peak in the 2000Hz–4000Hz frequency range. Therefore, it can be concluded that the acoustic superstructure 1 has a better smoothing effect on the speaker sensitivity curve.

[0079] Example 2

[0080] In Example 2, as Figures 9 to 11 As shown, this is a speaker provided in Embodiment 2 of the present invention. Unlike Embodiment 1, in Embodiment 2, two standing waves within the resonant cavity 21 cause two abnormal peaks or valleys in the sensitivity of the speaker body. Two acoustic superstructure units 11 are provided. Each abnormal peak or valley caused by a standing wave is smoothed by an acoustic superstructure unit 11, and the opening of each acoustic superstructure unit 11 is respectively located at the antinode of the corresponding standing wave.

[0081] For ease of understanding, let the two standing waves be a first standing wave and a second standing wave, respectively. The abnormal peak or valley caused by the first standing wave is the first abnormal peak or valley value, and the abnormal peak or valley caused by the second standing wave is the second abnormal peak or valley value. The two acoustic superstructure units 11 are a first unit and a second unit, respectively. The first abnormal peak or valley value is smoothed through the first unit, with the opening of the first unit close to the antinode of the first standing wave. The second abnormal peak or valley value is smoothed through the second unit, with the opening of the second unit close to the antinode of the second standing wave.

[0082] In other embodiments not shown in the figure, the abnormal peak or valley value induced by the same standing wave can also be smoothed by multiple acoustic superstructure units. That is, for each abnormal peak or valley value induced by the standing wave, at least one acoustic superstructure unit is required to smooth it. Appropriately increasing the number of acoustic superstructure units can improve the smoothing effect.

[0083] In Embodiment 2, the acoustic superstructure unit 11 adopts an extension tube acoustic superstructure unit 11b. In this case, an extension tube 112 is provided on the acoustic superstructure unit 11, and the axial direction of the extension tube 112 can be aligned with the depth direction of the back cavity 111 of the acoustic superstructure unit 11. Specifically, the extension tube 112 extends into the back cavity 111 of the acoustic superstructure unit 11 and communicates with the back cavity 111, and one end of the extension tube 112 protrudes from the acoustic superstructure unit 11 through a through hole 113 and communicates with the resonant cavity 21 of the housing 2, thereby connecting the back cavity 111 with the resonant cavity 21 of the housing 2. The end of the extension tube 112 protruding from the acoustic superstructure unit 11 is equivalent to the opening of the back cavity 111. In Embodiment 2, as... Figure 9 and Figure 10 As shown, the acoustic superstructure unit 11 is cylindrical in shape. In other embodiments, the speaker can be of any shape, such as a cylinder or a hexagonal prism, and the acoustic superstructure unit 11 can be cuboid (e.g., a rectangular parallelepiped). Figure 12 (as shown) or a hexagonal prism (such as) Figure 13 (as shown) and any other shape. The back cavity 111 of the acoustic superstructure unit 11 can be configured as a prism or a cylinder.

[0084] Figure 14 As shown, the speaker manufacturing method provided in Embodiment 2 of the present invention includes the following steps:

[0085] Step S1: Calculate the frequency response of the speaker body using finite element method and plot its sensitivity curve. Based on the sensitivity curve and frequency response results, determine the first abnormal peak frequency f corresponding to the first abnormal peak. 11 and the corresponding sound pressure distribution or the frequency f of the first abnormal valley corresponding to the first abnormal valley. 12 and the corresponding sound pressure distribution, the second abnormal peak frequency f corresponding to the second abnormal peak. 21 and the corresponding sound pressure distribution or the frequency f of the second abnormal valley corresponding to the second abnormal valley. 22 And the corresponding sound pressure distribution.

[0086] Step S2: Calculate the acoustic modes of the speaker resonant cavity 21 using finite element method, and at the first abnormal peak frequency f... 11 Or the first valley frequency f 12Search nearby for the first standing wave frequency f of the resonant cavity 21 that causes the first abnormal peak or the first abnormal trough. 10 (Acoustic modal frequency) and standing wave mode (acoustic modal shape), at the second abnormal peak frequency f 11 Or the frequency of the second abnormal valley value f 12 Search nearby for the second standing wave frequency f of the resonant cavity 21 that causes the second abnormal peak or second abnormal trough. 20 (Acoustic modal frequencies) and standing wave modes (acoustic modal shapes).

[0087] Step S3: Adjust the distribution of each of the acoustic superstructures 1 in the resonant cavity 21 so that the opening of the first unit is correspondingly set at the antinode of the first standing wave, and the opening of the second unit is correspondingly set at the antinode of the second standing wave, so that the first abnormal peak value or the first abnormal valley value can be smoothed by the first unit, and the second abnormal peak value or the second abnormal valley value can be smoothed by the second unit.

[0088] In other embodiments, if a certain abnormal peak or valley value is smoothed by multiple acoustic superstructure units, the openings of the multiple acoustic superstructure units corresponding to the abnormal peak or valley value must be close to the antinodes of the standing wave that caused the abnormal peak or valley value. Taking the smoothing of a first abnormal peak or valley value by multiple first units as an example, in this case, the openings of the multiple first units corresponding to the first abnormal peak or valley value are all positioned at the antinodes of the first standing wave. The multiple acoustic superstructure units can be arranged on the same plane.

[0089] Step S4: Adjust the structural parameters of the first unit and the second unit so that the first-order acoustic mode frequency of the first unit is similar to the first standing wave frequency f. 10 The first-order acoustic mode frequency of the second unit is equal to the second standing wave frequency f. 20 equal.

[0090] In Embodiment 2, the first-order acoustic mode frequency of the first unit and the first-order acoustic mode frequency of the second unit are calculated using the finite element method.

[0091] Specifically, in Example 2, as Figure 11 As shown, the interior of the speaker body forms a first acoustic domain I, a second acoustic domain II, a third acoustic domain III, and a fourth acoustic domain IV. The first acoustic domain I is the area within the resonant cavity 21 where the acoustic superstructure unit 11 is not located. The second acoustic domain II is located within the extension tube 112 and the through hole 113. The third acoustic domain III is the area within the back cavity 111 along the axis of the extension tube 112 (i.e.,...). Figure 11The x-direction (hereinafter referred to as x-direction) shown in the figure covers the area of ​​the extension tube 112, and the fourth acoustic domain IV is the area in the back cavity 111 that is misaligned with the extension tube 112 along the x-direction (i.e. does not cover the extension tube 112).

[0092] The acoustic superstructure unit 11 (first unit and second unit) adopts an extension tube acoustic superstructure unit 11b. The structural parameters of the extension tube acoustic superstructure unit 11b include the aperture d of the extension tube 112 (the peak absorption frequency increases with the increase of the aperture), the total length l2 of the extension tube 112 and the through hole 113 (the peak absorption frequency decreases with the increase of the length), the depths l3 and l4 of the back cavity 111 of the acoustic superstructure unit 11 (the peak absorption frequency decreases with the increase of the depth l3+l4), and the direction of the back cavity 111 perpendicular to the axis of the extension tube 112 (i.e., Figure 11 The cross-sectional area S3 or S4 in the x-direction (hereinafter referred to as the x-direction) is shown in the figure (the peak absorption frequency decreases as the area increases). Here, depth l3 is the depth of the back cavity 111 in the third acoustic domain III, depth l4 is the depth of the back cavity 111 in the fourth acoustic domain IV, and the depth direction is consistent with the x-direction. Cross-sectional area S3 is the cross-sectional area of ​​the back cavity 111 in the third acoustic domain III perpendicular to the x-direction, and cross-sectional area S4 is the cross-sectional area of ​​the back cavity 111 in the fourth acoustic domain IV along the direction perpendicular to the x-direction.

[0093] In Embodiment 2, when calculating the first-order acoustic mode frequency of the acoustic superstructure unit 11, an analytical method can be used to first calculate the sound absorption coefficient of the acoustic superstructure unit 11 (i.e., the extension tube acoustic superstructure unit 11b), and then extract the first sound absorption peak frequency of the sound absorption coefficient. The first sound absorption peak frequency of the sound absorption coefficient is the first-order acoustic mode frequency of the acoustic superstructure unit.

[0094] Furthermore, the calculation process for the sound absorption coefficient of the extended tube acoustic superstructure unit 11b is as follows:

[0095] (1) Based on the volume velocity continuity and impedance transfer formula, the acoustic impedance Z2 (x = l2) of the second acoustic domain II at x = l2 satisfies the following relationship:

[0096] Where Z3 represents the acoustic impedance of the third acoustic domain Ⅲ at x = l2, and satisfies the following relationship: Z4 represents the acoustic impedance ratio of the fourth acoustic domain IV at x = l2, and satisfies the following relationship:

[0097] In the above formula, j represents the imaginary unit, S2 represents the cross-sectional area of ​​the second acoustic domain II in the vertical x direction; Z0 represents the characteristic impedance of air and satisfies the formula Z0=ρ0c0; ρ0 is the air density.

[0098] (2) According to the impedance transfer formula, the acoustic impedance Z2 (x=0) of the second acoustic domain II at x=0 satisfies the following relationship:

[0099] Among them, Z n This represents the equivalent characteristic impedance of the air inside the extension tube 112, and satisfies the following relationship: k n Let represent the equivalent wavenumber of the air inside extension tube 112, and satisfy the following relationship:

[0100] In the above relationship, ρ n This represents the equivalent density of the air inside the extension tube 112, and satisfies the following relationship: K n This represents the equivalent bulk modulus of the air inside the extension tube 112, and satisfies the following relationship: Wherein, the parameter s satisfies the relation μ represents the aerodynamic viscosity coefficient; γ represents the specific heat ratio; P0 represents the static air pressure; P r Let J0 and J1 represent the Prandtl number of air, and J0 and J1 represent the 0th and 1st order Bessel functions, respectively.

[0101] (3) Corrected impedance Z at both ends of extension tube 112 corr Satisfying the relation: Z corr =2βR S +jδωρ0d / 2.

[0102] The parameter β satisfies the relationship β = 5.08s. -1.45 +1.7-0.002d / l², the parameter δ satisfies the relationship δ=0.97e -0.2s +1.54-0.003d / l2, parameter R S Satisfying the relation

[0103] (4) The surface acoustic impedance Z of the extended tube acoustic superstructure unit 11b s Satisfying the relation:

[0104] (5) The sound absorption coefficient α1 of the acoustic superstructure unit 11b of the extension tube satisfies the following relationship:

[0105] Step S5: Calculate the frequency response of the speaker with the acoustic superstructure 1 and plot the sensitivity curve of the speaker to determine the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker. If the smoothing effect is not good, repeat steps S3 to S5 until a satisfactory smoothing effect is obtained.

[0106] The detailed steps of step S5 are the same as those in step S5 of embodiment one, and will not be repeated here.

[0107] Step S6 involves experimentally verifying the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker. If the smoothing effect is unsatisfactory, steps S3 to S6 are repeated until a satisfactory smoothing effect is obtained.

[0108] In step S6, the detailed steps of "verifying the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker" are basically the same as those of "determining the smoothing effect of the acoustic superstructure 1 on the sensitivity curve of the speaker" in step S5. The only difference is that in step S5, the sensitivity is obtained by calculation, while in step S6, the sensitivity is obtained through experimentation. These details will not be repeated here.

[0109] In other embodiments, the acoustic superstructure unit 11 may also be a coiled extension tube acoustic superstructure unit 11c (e.g., Figure 15 As shown), the coiled back cavity extension tube acoustic superstructure unit 11d (as shown) Figure 16 As shown), the coiled back cavity coiled extension tube acoustic superstructure unit 11e (as shown) Figure 17 (as shown), or the curled back cavity perforated plate acoustic superstructure unit 11f (such as...) Figure 18 (As shown).

[0110] Among them, such as Figure 15 As shown, replacing the extension tube 11 of the extension tube acoustic superstructure unit 11b with a coiled extension tube results in a coiled extension tube acoustic superstructure unit 11c. The structural parameters of the acoustic superstructure unit 11 include the aperture of the coiled extension tube (the peak absorption frequency increases with the increase of the aperture), the equivalent length of the coiled extension tube (the peak absorption frequency decreases with the increase of the length), the depth of the back cavity 111 of the acoustic superstructure unit 11 (the peak absorption frequency decreases with the increase of the depth), and the cross-sectional area of ​​the back cavity in the direction perpendicular to the depth (the peak absorption frequency decreases with the increase of the area).

[0111] like Figure 16 As shown, by connecting a straight extension tube 112 to the through hole 113 of the curled back cavity Helmholtz resonance acoustic superstructure unit 11a, a curled back cavity extension tube acoustic superstructure unit 11d can be obtained. The structural parameters of the acoustic superstructure unit 11 include the aperture of the extension tube (the peak absorption frequency increases with the increase of the aperture), the length of the extension tube (the peak absorption frequency decreases with the increase of the length), the equivalent depth of the back cavity (the peak absorption frequency decreases with the increase of the depth), and the dimensions of the back cavity in the cross section perpendicular to its centerline 114.

[0112] like Figure 17As shown, by connecting a coiled extension tube 112 to the through hole 113 of the coiled back cavity Helmholtz resonance acoustic superstructure unit 11a, a coiled back cavity coiled extension tube acoustic superstructure unit 11e can be obtained. The structural parameters of the acoustic superstructure unit 11 include the aperture of the coiled extension tube (the peak absorption frequency increases with the increase of the aperture), the equivalent length of the coiled extension tube (the peak absorption frequency decreases with the increase of the length), the equivalent depth of the back cavity (the peak absorption frequency decreases with the increase of the depth), and the dimensions of the back cavity in the cross section perpendicular to its centerline 114.

[0113] like Figure 18 As shown, by increasing the number of through holes 113 in the curled-back cavity Helmholtz resonance acoustic superstructure unit 11a, a curled-back cavity perforated plate acoustic superstructure unit 11f can be obtained. The structural parameters of the acoustic superstructure unit 11 include the aperture of the through holes (the peak absorption frequency increases with the increase of the aperture), the depth of the through holes (the peak absorption frequency decreases with the increase of the depth), the number of through holes (the peak absorption frequency increases with the increase of the number), the equivalent depth of the back cavity (the peak absorption frequency decreases with the increase of the depth), and the dimensions of the back cavity in the cross section perpendicular to its centerline 114.

[0114] Furthermore, the coiled extension tube and the coiled back cavity can be any coiled channel, such as a square spiral channel or an Archimedean spiral channel.

[0115] The speaker and its manufacturing method provided in the above embodiments of the present invention include an acoustic superstructure 1 composed of at least one acoustic superstructure unit 11 within the resonant cavity 21, with the opening of each acoustic superstructure unit 11 positioned close to the antinode of the standing wave. By adjusting the structural parameters of the acoustic superstructure 1, its first-order acoustic mode frequency is made equal to the frequency of the standing wave that causes abnormal peaks or valleys. The interaction between the acoustic superstructure 1 and the resonant cavity 21 smooths out the abnormal peaks or valleys generated by the standing waves in the speaker body. This speaker can reduce the negative impact of standing waves without increasing the speaker's volume. Furthermore, the acoustic superstructure 1 can be integrally formed with the speaker cabinet 2, and can be manufactured using mold making or 3D printing, making manufacturing convenient and cost-effective. It can also improve the speaker's rigidity and reduce the risk of noise caused by vibration of the speaker cabinet 2.

[0116] In addition, the speaker provided in this embodiment of the invention only affects the sensitivity of the speaker near the first-order acoustic mode frequency of the acoustic superstructure, while having very little effect on other frequency bands.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A speaker, characterized in that, The system includes a speaker body and an acoustic superstructure unit. The speaker body includes a cabinet and a speaker. A resonant cavity is formed inside the cabinet. The cabinet has a mounting hole that communicates with the resonant cavity. The speaker is installed at the mounting hole to block the mounting hole and seal the resonant cavity. The acoustic superstructure unit has a back cavity, and the acoustic superstructure unit has a through hole communicating with the back cavity. The through hole is also communicating with the resonant cavity. The through hole of the acoustic superstructure unit is adjacent to the antinode of the standing wave that causes abnormal peak or abnormal valley values, and is used to smooth the abnormal peak or abnormal valley values ​​caused by the standing wave. A partition plate is provided inside the back cavity. The partition plate extends spirally inside the back cavity to form a spiral channel inside the back cavity. One end of the spiral channel is connected to the through hole. The back cavity is also provided with a layered plate, which is perpendicular to the partition plate and divides the spiral channel into a first channel and a second channel. One end of the first channel is connected to the through hole, and the layered plate has a notch so that the other end of the first channel is connected to one end of the second channel.

2. The speaker according to claim 1, characterized in that, The abnormal peak or abnormal valley includes multiple values, and each abnormal peak or abnormal valley is provided with at least one of the acoustic superstructure units.

3. The speaker according to claim 2, characterized in that, The acoustic superstructure unit corresponding to the same abnormal peak or abnormal valley has the same size parameters.

4. The speaker according to claim 2, characterized in that, The first-order acoustic mode frequency of the acoustic superstructure unit is equal to the standing wave frequency that triggers the corresponding abnormal peak or abnormal valley.

5. The speaker according to claim 4, characterized in that, The first-order acoustic mode frequency of each of the acoustic superstructure units is determined according to the size of the through-hole and the size of the back cavity.

6. The speaker according to claim 1, characterized in that, The acoustic superstructure unit is also provided with an extension tube, which is located in the back cavity. One end of the extension tube is connected to the resonant cavity through the through hole, and the other end of the extension tube is connected to the back cavity.

7. The speaker according to claim 6, characterized in that, At least a portion of the extension tube extends in a straight line, or at least a portion of the extension tube extends in a curve.

8. The speaker according to claim 1, characterized in that, The acoustic superstructure unit and the housing are integrally formed.

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