CN113490109B - Acoustic module and electronic equipment - Google Patents

Abstract

The application discloses an acoustic module and electronic equipment, and belongs to the technical field of audio. The disclosed acoustic module comprises a first shell and a loudspeaker monomer, wherein the first shell is provided with a first accommodating cavity, and the loudspeaker monomer is arranged in the first accommodating cavity; the loudspeaker unit comprises a first vibrating diaphragm, and the first vibrating diaphragm limits the first accommodating cavity into a front sound cavity and a rear sound cavity; the acoustic module comprises a second vibrating diaphragm, the second vibrating diaphragm is arranged in the rear sound cavity, a sealed tuning space is defined in the rear sound cavity, tuning medium is filled in the tuning space, and the density of the tuning medium is smaller than that of air. The scheme can improve the low-frequency performance of the acoustic module and effectively reduce the resonance peak of the frequency response.

Description

Acoustic modules and electronic equipment

Technical Field

The present application belongs to the field of audio technology, and specifically relates to an acoustic module and an electronic device.

Background technique

With the advancement of technology, the performance of electronic devices such as mobile phones and tablets has been continuously improved. Among them, as users' requirements for audio-visual functions become higher and higher, the quality of speaker modules needs to be improved.

In the related art, the speaker module includes a shell and a speaker unit. The speaker unit divides the shell into a front sound cavity and a rear sound cavity. The industry adopts filling the rear sound cavity with sound-absorbing materials to improve the low-frequency performance. However, the operation process of this method is relatively cumbersome and the improvement in low-frequency performance is limited. At the same time, it will also cause the speaker module to have a higher frequency response resonance peak and affect the overall acoustic performance.

Summary of the invention

The purpose of the embodiments of the present application is to provide an acoustic module and an electronic device to improve the low-frequency performance of the acoustic module and effectively reduce the frequency response resonance peak.

In order to solve the above technical problems, this application is implemented as follows:

In a first aspect, an embodiment of the present application provides an acoustic module, which includes a first housing and a speaker unit, wherein the first housing has a first receiving cavity, and the speaker unit is disposed in the first receiving cavity; the speaker unit includes a first diaphragm, and the first diaphragm defines a front sound cavity and a rear sound cavity in the first receiving cavity;

The acoustic module includes a second diaphragm, which is arranged in the rear sound cavity and defines a sealed tuning space in the rear sound cavity. The tuning space is filled with a tuning medium, and the density of the tuning medium is less than the density of air.

In a second aspect, an embodiment of the present application provides an electronic device, which includes the acoustic module provided in the first aspect of the embodiment of the present application, the electronic device includes a first shell, a second shell and a functional device, the first shell and the second shell are combined to form a second receiving cavity, and the functional device and the acoustic module are positioned in the second receiving cavity.

In the embodiment of the present application, since the second diaphragm defines a sealed tuning space in the rear sound cavity, when the speaker unit is working, the sound waves in the rear sound cavity will act on the second diaphragm and drive the second diaphragm to vibrate; at the same time, since the density of the tuning medium in the tuning space is less than the density of air, the equivalent compliance of the tuning medium can produce positive compliance in the low frequency band when the second diaphragm vibrates, which can pull up the low frequency and improve the low frequency performance of the acoustic module; precisely because the density of the tuning medium is less than the density of air, the second diaphragm is difficult to match the frequency of the first diaphragm when vibrating, especially in the high frequency band, the vibration of the second diaphragm in the tuning space can produce anti-resonance, which can effectively lower the resonance peak of the speaker unit and reduce the frequency response resonance peak of the acoustic module, thereby improving sound quality distortion and optimizing the acoustic performance of the acoustic module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the exploded structure of an acoustic module disclosed in an embodiment of the present application;

FIG2 is an isometric cross-sectional view of the acoustic module disclosed in an embodiment of the present application;

FIG3 is a partial enlarged view of point A in FIG2 ;

FIG4 is a partial cross-sectional view of an electronic device disclosed in an embodiment of the present application;

FIG5 is an electrical analog schematic diagram of the acoustic module disclosed in the embodiment of the present application;

FIG6 is a schematic diagram showing the relationship between the changing force compliance and the frequency of the acoustic module disclosed in the embodiment of the present application;

FIG. 7 is a comparison diagram of the frequency response curves of the acoustic module disclosed in the embodiment of the present application and the related art.

Description of reference numerals:

100-first housing, 110-first sub-housing, 120-second sub-housing,

200-speaker unit, 210-first diaphragm,

300-synergistic component, 310-second diaphragm, 320-second shell, 330-tuning mass block,

400-carrying platform, 410-step part,

500-Dustproof parts,

600-first shell, 700-second shell, 800-screen, 900-battery,

C1-front sound cavity, C2-rear sound cavity, C3-tuning space, C4-second receiving cavity,

G1-vibration gap, G2-installation slot, P-sound guide channel, H-sound outlet hole.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and/or" in the specification and claims represents at least one of the connected objects, and the character "/" generally indicates that the objects associated with each other are in an "or" relationship.

The technical solution disclosed in the embodiments of the present application is described in detail below in conjunction with the accompanying drawings.

In order to solve the technical problems of poor low-frequency performance and high frequency response resonance peak of the speaker in the related art, the embodiment of the present application provides an acoustic module. As shown in Figures 1 to 4, the acoustic module disclosed in the embodiment of the present application includes a first shell 100, a speaker unit 200 and a second diaphragm 310. In the embodiment of the present application, there can be many specific types of acoustic modules, such as speakers, receivers, headphones, etc., which are not limited in the embodiment of the present application.

Among them, the first shell 100 is the basic component of the acoustic module, which provides an installation foundation for other components of the acoustic module and also plays a certain protective function. Specifically, as shown in Figures 1 and 2, the first shell 100 has a first receiving cavity, and the speaker unit 200 and the second diaphragm 310 are both arranged in the first receiving cavity. In order to facilitate disassembly and assembly, the first shell 100 may include a first sub-shell 110 and a second sub-shell 120, and the first sub-shell 110 and the second sub-shell 120 are combined to form a first receiving cavity; in the embodiments of Figures 1 and 2, during assembly, the speaker unit 200 and the second diaphragm 310 are first installed on the first sub-shell 110, and then the second sub-shell 120 is snap-fitted and docked on the first sub-shell 110, that is, the assembly of the acoustic module is realized; when the acoustic module needs to be inspected and maintained, the second sub-shell 120 can be removed from the first sub-shell 110.

The speaker unit 200 is the main sound-generating component of the acoustic module, which includes a first diaphragm 210. When the speaker unit 200 is working, it will drive the first diaphragm 210 to vibrate. The first diaphragm 210 will push the air in the first receiving cavity to generate sound waves. The first shell 100 is provided with a sound guide channel P connected to the outside, and the sound guide channel P is connected to the first receiving cavity, so the sound waves generated by the speaker unit 200 can be transmitted through the sound guide channel P. Of course, in order to be able to sound normally, the first diaphragm 210 defines the first receiving cavity into a front sound cavity C1 and a rear sound cavity C2, and the first diaphragm 210 generates sound waves by vibrating alternately toward the front sound cavity C1 and the rear sound cavity C2.

The second diaphragm 310 of the embodiment of the present application is disposed in the rear sound cavity C2 and defines a sealed tuning space C3 in the rear sound cavity C2. The tuning space C3 is filled with a tuning medium, and the density of the tuning medium is less than the density of air.

It should be understood that, based on the arrangement of the second diaphragm 310, the second diaphragm 310 also divides the rear sound cavity C2 into the tuning space C3 and another chamber. When the first diaphragm 210 vibrates, the sound waves generated in the rear sound cavity C2 will propagate to the second diaphragm 310 and push the second diaphragm 310 to vibrate. The vibrating second diaphragm 310 will squeeze the tuning medium in the tuning space C3. Under the dual vibration of the first diaphragm 210 and the second diaphragm 310, the low-frequency performance of the acoustic module is improved. Specifically, when the second diaphragm 310 vibrates, the equivalent compliance of the tuning medium in the tuning space C3 is a composite compliance that varies with frequency, but in general, the equivalent compliance of the tuning medium can produce positive compliance in the low-frequency band, thereby achieving the goal of pulling up the low frequency and improving the low-frequency performance of the acoustic module.

At the same time, since the density of the tuning medium is less than the density of air, when the second diaphragm 310 vibrates, its frequency will gradually become different from the frequency of the first diaphragm 210. In the process of gradually increasing frequency, the frequency matching degree between the two will become lower and lower; after entering the high frequency band, the vibration of the second diaphragm 310 in the tuning space C3 will produce an anti-resonance opposite to the resonance peak of the speaker unit 200. The anti-resonance of the second diaphragm 310 will hinder the absorption and lower the resonance peak of the speaker unit 200, thereby reducing the overall frequency response resonance peak of the acoustic module, thereby achieving the purpose of improving sound quality distortion and optimizing the acoustic performance of the acoustic module.

In the embodiment of the present application, there can be multiple types of tuning media, which can be selected as helium and neon. Both helium and neon are inert gases with excellent safety and reliability. Alternatively, the tuning medium can also be selected as hydrogen, ammonia and other gases with a density less than that of air, but due to safety considerations, their applicability will be lower. However, based on the premise of realizing the role of the tuning medium in the embodiment of the present application, the above gases can meet the requirements.

It can be seen from the above description that in the embodiment of the present application, since the second diaphragm 310 defines a sealed tuning space C3 in the rear sound cavity C2, when the speaker unit 200 is working, the sound waves in the rear sound cavity C2 will act on the second diaphragm 310 and drive the second diaphragm 310 to vibrate; at the same time, since the density of the tuning medium in the tuning space C3 is less than the density of air, the equivalent compliance of the tuning medium when the second diaphragm 310 vibrates can produce positive compliance in the low frequency band, which can pull up the low frequency and improve the low frequency performance of the acoustic module; precisely because the density of the tuning medium is less than the density of air, the second diaphragm 310 is difficult to match the frequency of the first diaphragm 210 when vibrating, especially in the high frequency band, the vibration of the second diaphragm 310 in the tuning space C3 can produce anti-resonance, which can effectively lower the resonance peak of the speaker unit 200 and reduce the frequency response resonance peak of the acoustic module, thereby improving the sound quality distortion and optimizing the acoustic performance of the acoustic module.

As shown in FIGS. 1 to 3 , the acoustic module of the embodiment of the present application may include an enhancement component 300 , which includes a second diaphragm 310 , a tuning medium, and a second shell 320 , wherein a tuning space C3 is defined between the second diaphragm 310 and the second shell 320 .

It should be understood that in the aforementioned embodiment where the rear sound cavity C2 is not provided with the second shell 320, the second diaphragm 310 can define a tuning space C3 with the inner wall of the first shell 100. This solution reuses the inner wall of the first shell 100 to improve the compactness of the structure, but will result in higher installation costs. In this embodiment, the second diaphragm 310, the tuning medium and the second shell 320 are combined to form an enhancement component 300, so that the enhancement component 300 is designed as a modular component, and the tuning space C3 filled with the tuning medium is always constructed inside. Therefore, during the assembly process of the acoustic module, it is only necessary to fix the enhancement component 300 in the rear sound cavity C2, without considering how to set the second diaphragm 310 to construct the tuning space C3 and how to fill the tuning medium. It can be seen that the enhancement component 300 undoubtedly simplifies the installation process and reduces the installation cost. At the same time, the modular enhancement component 300 is also convenient for mass production, thereby reducing manufacturing costs.

In order to strengthen the vibration effect of the second diaphragm 310, as shown in FIGS. 1 to 3, the enhancement component 300 of the embodiment of the present application may also include a tuning mass block 330, which is disposed on the second diaphragm 310. It should be understood that the tuning mass block 330 has a certain mass, which increases the load on the second diaphragm 310, thereby changing the vibration frequency and vibration amplitude of the second diaphragm 310 to achieve the purpose of strengthening the vibration effect of the second diaphragm 310. On the basis of strengthening the vibration effect of the second diaphragm 310, the enhancement component 300 can undoubtedly further improve the low-frequency performance of the acoustic module and further reduce the frequency response resonance peak of the acoustic module.

Of course, the edge area of the second diaphragm 310 in the embodiment of the present application may be provided with a folding ring, and the vibration effect of the second diaphragm 310 may be further enhanced by the folding ring.

In the above-mentioned embodiment where the enhancement component 300 includes the tuning mass block 330, in order to demonstrate the beneficial effects of the acoustic module of the embodiment of the present application, the embodiment of the present application performs an electric power-acoustic analogy, and the specific contents are as follows:

As shown in FIG5 , FIG5 shows an electrical analogy schematic diagram of the acoustic module, wherein C ₀ is the force compliance of the original system (when the enhancement component 300 is not set), the dotted frame is the added enhancement component 300, C _m is the acoustic capacitance (acoustic compliance) of the second diaphragm 310 in the enhancement component 300, M _m is the mass of the tuning mass block 330 in the enhancement component 300, R _m is the acoustic resistance of the enhancement component 300, C ₂ is the acoustic compliance of the tuning medium in the enhancement component 300, P is the air pressure in the tuning space C3, and U is the volume flow velocity.

Make an electric-acoustic analogy: _Cm - _Cm , _Mm -L, _Rm -R, P-Ee, UI; where L is inductance, R is resistance, Ee is electromotive force, and I is current.

The original impedance of the system is:

After adding 300 booster components, the impedance is:

Define the equivalent force order C _eff , then

but

Define the resonant frequency ω ₀ of the synergistic assembly 300,

but

After rationalizing the denominator, take the real part.

make

but

Re(C _eff )＝C ₀ +ΔC _eff

From the above derivation, it can be seen that compared with the original system, the acoustic module of the embodiment of the present application can add a variable force compliance ΔC _eff that changes with the driving frequency ω to the original force compliance C _0. Therefore, it is only necessary to control various parameters to change the value of the variable force compliance ΔC _eff . When the variable force compliance ΔC _eff is a positive value, the overall force compliance of the acoustic module becomes larger. When the variable force compliance ΔC _eff is a negative value, the overall force compliance of the acoustic module becomes smaller.

In-style In the embodiment, the inductance L, the resistance R and the resonant frequency ω ₀ of the enhancement component 300 can be arbitrarily combined and changed by correspondingly tuning the mass of the mass block 330 , the acoustic impedance of the enhancement component 300 and the vibration frequency of the second diaphragm 310 .

Optionally, set the following parameters:

variable Value (national standard unit) L(corresponding to Mm) 50e-6 R(corresponding to Rm) 10e-3 ω ₀ 4000

The relationship between ΔC _eff and the driving frequency ω is shown in FIG6 .

Based on FIG6 , it can be seen that after adding the enhancement component 300, the equivalent compliance of the tuning medium included in the enhancement component 300 is a composite compliance that varies with frequency, which can produce positive compliance in the low-frequency band, thereby reducing the overall compliance of the rear cavity, reducing f0 and pulling up the low frequency; at the same time, in the high-frequency band area, it can produce an anti-resonance opposite to the resonance peak of the speaker unit 200, which can lower the peak value at the high-frequency resonance peak fh (see FIG7 ), thereby reducing noise, improving distortion, and ultimately optimizing the acoustic performance of the acoustic module.

To facilitate the installation of the speaker unit 200, as shown in FIGS. 1 to 3, a supporting platform 400 may be provided in the first receiving cavity of the embodiment of the present application. The supporting platform 400 is used to support at least part of the edge of the speaker unit 200 for installation. The supporting platform 400 is the installation base of the speaker unit 200. Since the first diaphragm 210 of the speaker unit 200 divides the first receiving cavity into the front sound cavity C1 and the rear sound cavity C2, the supporting platform 400 is also located between the front sound cavity C1 and the rear sound cavity C2, which assists in realizing the separation of the first receiving cavity.

At the same time, a mounting groove G2 matching the synergistic component 300 can be defined between the carrier 400 and the first shell 100 of the embodiment of the present application, and the synergistic component 300 is arranged in the mounting groove G2. In this arrangement, the carrier 400 supports the synergistic component 300 and can limit the synergistic component 300. Therefore, the carrier 400 of the embodiment of the present application realizes functional reuse, which is conducive to improving the compactness of the structure inside the acoustic module.

It should be understood that the support platform 400 of the embodiment of the present application can be configured to support a partial edge of the speaker unit 200, and the other edges of the speaker can be supported by a supporting structure formed by the extension of the inner wall of the first shell 100, or the support platform 400 of the embodiment of the present application can be configured to support the entire edge of the speaker unit 200.

The embodiment of the present application does not limit the shape of the enhancement component 300, which may be a square body, a cylinder, or other shapes. Of course, as the shape of the enhancement component 300 changes, the mounting groove G2 may adaptively adjust its shape to fit the enhancement component 300.

The embodiment of the present application also does not limit the specific setting position of the enhancement component 300. As shown in FIG. 4, the enhancement component 300 is set on the bottom wall of the first shell 100. In other embodiments, under the premise that the second diaphragm 310 faces the rear sound cavity C2, the enhancement component 300 can be set on the top wall, side wall and other areas of the first shell 100.

Furthermore, in order to improve the installation stability of the speaker unit 200, as shown in FIG1 and FIG3, the supporting platform 400 of the embodiment of the present application is provided with a step portion 410 on the end surface of one side facing the speaker unit 200, and the shape of the step portion 410 matches the shape of the speaker unit 200, and the speaker unit 200 is installed on the step portion 410. It should be understood that the step portion 410 includes a bottom surface and a side surface, the bottom surface of the step portion 410 can support the speaker unit 200, and the side surface of the step portion 410 limits the outer peripheral surface of the speaker unit 200 to stop the speaker unit 200, thereby improving the installation stability of the speaker unit 200; under such a setting, even if the first diaphragm 210 vibrates at a higher frequency, it will not cause the speaker unit 200 to shift.

As shown in FIG. 2 and FIG. 4 , the first diaphragm 210 of the embodiment of the present application can be parallel to the second diaphragm 310. It should be understood that the second diaphragm 310 is vibrated under the impetus of the sound waves generated by the vibration of the first diaphragm 210. Under this structural layout, the second diaphragm 310 and the first diaphragm 210 have the same vibration direction, which makes it easier for the sound waves generated by the first diaphragm 210 to exert a driving effect on the second diaphragm 310, thereby helping to strengthen the driving effect of the synergistic component 300, so as to enhance the synergistic effect of the synergistic component 300.

In order to facilitate the second diaphragm 310 to vibrate smoothly, a vibration gap G1 may be provided between the second diaphragm 310 and the first inner wall of the first shell 100 of the embodiment of the present application. The vibration gap G1 is for the second diaphragm 310 to vibrate. The first inner wall is the inner wall on the first shell 100 opposite to the second diaphragm 310. It should be understood that, on the one hand, the vibration gap G1 of the embodiment of the present application provides an escape space for the vibration action of the second diaphragm 310. Due to the existence of the vibration gap G1, when the second diaphragm 310 vibrates toward the first inner wall, the second diaphragm 310 is prevented from vibrating to contact with the first inner wall. In this way, the second diaphragm 310 will not be interfered by the first inner wall, thereby ensuring that the second diaphragm 310 can vibrate smoothly. On the other hand, the vibration gap G1 is also used to ensure the smoothness of the airflow when the second diaphragm 310 vibrates, reducing the distortion of the second diaphragm due to the influence of air pressure.

The embodiment of the present application does not limit the specific size of the vibration gap G1. In an optional solution, as shown in FIG4 , the distance between the second diaphragm 310 and the first inner wall of the embodiment of the present application is a, and the value range of a can be a ≥ 0.2 mm. In this setting, the distance a between the second diaphragm 310 and the first inner wall of the embodiment of the present application is limited to a lower limit of 0.2 mm. As long as a is not less than 0.2 mm, the second diaphragm 310 can achieve smooth vibration, thereby avoiding the design of the distance a being too low; at the same time, based on the design requirements, as long as it is not less than 0.2 mm, the distance a can be set as small as possible, which can improve the structural compactness of the acoustic module.

As shown in FIG2 , the first housing 100 of the embodiment of the present application is provided with a sound guide channel P, which is connected to the front sound cavity C1, and the sound guide channel P, the speaker unit 200 and the enhancement component 300 can be arranged in the same direction in sequence in the first housing 100. Specifically, under this structural layout, the guide channel, the front sound cavity C1, the speaker unit 200, the rear sound cavity C2 and the enhancement component 300 are all located in the same direction, which can make the structural layout of the acoustic module more regular, which is not only convenient for processing but also conducive to improving the structural compactness of the acoustic module.

At the same time, under such a configuration, the sound waves generated by the speaker unit 200 in the rear sound cavity C2 and the front sound cavity C1 can be transmitted to the outside of the acoustic module through the front sound cavity C1 and the sound guide channel P in turn, and the enhancement effect of the enhancement component 300 is also located in the arrangement direction of the above-mentioned structure, thereby avoiding excessive loss caused by the sound waves in the acoustic module propagating along the tortuous propagation path. When the propagation path of the sound waves is shortened, the sound quality of the acoustic module can undoubtedly be optimized.

Of course, the embodiment of the present application does not limit the specific setting position of the enhancement component 300, which can be offset from the speaker unit 200 and/or the sound guide channel P.

As shown in Figure 4, based on the aforementioned acoustic module, an embodiment of the present application also provides an electronic device, which includes the acoustic module mentioned in any of the aforementioned schemes, so that the electronic device has the beneficial effects of any of the aforementioned schemes, which will not be repeated here; the electronic device includes a first shell 600, a second shell 700 and a functional device, the first shell 600 and the second shell 700 are combined to form a second receiving cavity C4, and the functional device and the acoustic module are positioned in the second receiving cavity C4.

The first housing 600 and the second housing 700 are basic components of the electronic device, and the two can be detachably arranged to facilitate the disassembly and assembly of the electronic device as a whole. The second receiving cavity C4 is the installation space inside the electronic device. When the functional device and the acoustic module are positioned and installed in the second receiving cavity C4, the assembly process of the functional device and the acoustic module is completed.

The electronic device referred to in the embodiments of the present application may be a smart phone, a tablet computer, an e-book reader, a wearable device, or the like. The embodiments of the present application do not limit the specific type of the electronic device.

In order to improve the structural compactness of the electronic device, a first receiving cavity can be formed between the first housing 600, the second housing 700 and at least part of the functional device in the embodiment of the present application, and the speaker unit 200 and the second diaphragm 310 of the acoustic module are arranged in the first receiving cavity. It should be understood that under this structural layout, the first shell 100 of the acoustic module is replaced by at least part of the inner wall of the first housing 600, the inner wall of the second housing 700 and the outer wall of the functional device. It can be seen that on the basis of simplifying the structure of the acoustic module, the electronic device of the embodiment of the present application also realizes the reuse of part of its internal structure, which can undoubtedly improve the structural compactness of the electronic device and meet the design concept of thinness.

The specific types of functional components are not limited in this embodiment, and may include but are not limited to a battery 900 , a main board, a sub-board, etc. Of course, in an embodiment where the electronic device includes a screen 800 , the screen 800 may also be used to replace the first housing 100 .

In order to propagate the sound waves emitted by the acoustic module outside the electronic device, a sound outlet hole H is opened at a position corresponding to the sound guide channel P on the first shell 600 or the second shell 700, and the sound outlet hole H is connected to the sound guide channel P so that the sound waves can be smoothly propagated outside the electronic device.

In order to prevent foreign matter outside the electronic device (such as water stains, dust, etc.) from entering the interior of the electronic device, the sound guide channel of this embodiment can be provided with a dustproof part 500; further, the dustproof part 500 can be arranged in the area of the first shell 100 corresponding to the sound guide channel P, and there can be various types of dustproof parts 500, such as a dustproof net, a dustproof sponge, a dustproof cloth, etc.

The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims (11)

1. An acoustic module, characterized in that it comprises a first housing, a speaker unit and an enhancement component, wherein the first housing has a first receiving cavity, and the speaker unit is disposed in the first receiving cavity; the speaker unit comprises a first diaphragm, and the first diaphragm defines a front sound cavity and a rear sound cavity in the first receiving cavity; The enhancement component includes a second diaphragm, a tuning medium and a second shell. The second diaphragm is arranged in the rear sound cavity. The second diaphragm and the second shell define a sealed tuning space in the rear sound cavity. The tuning space is filled with a tuning medium, and the density of the tuning medium is less than the density of air. 2. The acoustic module according to claim 1, characterized in that the first diaphragm is parallel to the second diaphragm. 3. The acoustic module according to claim 1, characterized in that the tuning medium is helium. 4. The acoustic module according to claim 1 is characterized in that a vibration gap is arranged between the second diaphragm and the first inner wall of the first shell, the vibration gap is provided for the second diaphragm to vibrate, and the first inner wall is the inner wall of the first shell opposite to the second diaphragm. 5 . The acoustic module according to claim 4 , wherein the distance between the second diaphragm and the first inner wall is a, and the value range of a is a≥0.2 mm. 6. The acoustic module according to claim 1 is characterized in that the enhancement component further comprises a tuning mass block, and the tuning mass block is arranged on the second diaphragm. 7. The acoustic module according to claim 1 is characterized in that a supporting platform is arranged in the first receiving cavity, and the supporting platform is used to support and install at least a part of the edge of the speaker unit; an installation groove matching the enhancement component is defined between the supporting platform and the first shell, and the enhancement component is arranged in the installation groove. 8. The acoustic module according to claim 7 is characterized in that the supporting platform is provided with a step portion on the end surface of one side facing the speaker unit, the shape of the step portion matches the shape of the speaker unit, and the speaker unit is installed on the step portion. 9. The acoustic module according to claim 1 is characterized in that the first shell is provided with a sound guide channel, the sound guide channel is connected to the front sound cavity, and the sound guide channel, the speaker unit and the enhancement component are arranged in sequence along the same direction in the first shell. 10. An electronic device, characterized in that it comprises the acoustic module described in any one of claims 1 to 9, the electronic device comprises a first shell, a second shell and a functional device, the first shell and the second shell are combined to form a second receiving cavity, and the functional device and the acoustic module are positioned in the second receiving cavity. 11. The electronic device according to claim 10 is characterized in that the first receiving cavity is formed between the first shell, the second shell and at least part of the functional device, and the speaker unit and the second diaphragm of the acoustic module are arranged in the first receiving cavity.