Resonance device and sound box

Abstract

The invention provides a resonance device and a sound box. The resonance device comprises a loudspeaker; the front cavity is arranged on the front side of the loudspeaker; the sound tube is connected with one side, far away from the loudspeaker, of the front cavity, the sound tube is communicated with the front cavity, the cross sectional area of one end, close to the front cavity, of the sound tube is a first cross sectional area, the cross sectional area of one end, far away from the front cavity, of the sound tube is a second cross sectional area, and the first cross sectional area is smaller than the second cross sectional area. The resonance device can meet the requirements of loudness improvement and miniaturization.

Description

Technical Field

[0001] This invention relates to the field of audio equipment technology, and more particularly to a resonance device and a speaker. Background Technology

[0002] In the current technological field, the commonly used techniques for achieving bass functionality are bass-reflex enclosures or passive radiator (PR) enclosures. These solutions heavily rely on high-performance speaker units and large enclosure structures; however, this dependence results in drawbacks such as large space requirements and high manufacturing costs in practical applications. Existing technologies typically use wooden or plastic enclosures to address these drawbacks, but wooden enclosures suffer from abrupt changes in channel cross-section, while plastic enclosures struggle to maintain dimensional stability.

[0003] In addition, the traditional closed-tube resonance scheme is also one of the common methods used in existing technologies to achieve bass function. However, the traditional closed-tube resonance scheme also has many problems such as low loudness and insufficient optimization of structural size, which makes it difficult to simultaneously achieve bass effect and meet the requirements of device miniaturization. Summary of the Invention

[0004] This application provides a resonance device and a speaker, which can meet the requirements of loudness enhancement and miniaturization.

[0005] This application provides a resonance device, including: speaker; The front cavity is located on the front side of the speaker; A sound tube is connected to the side of the front cavity away from the speaker. The sound tube communicates with the front cavity. The cross-sectional area of ​​the end of the sound tube near the front cavity is a first cross-sectional area, and the cross-sectional area of ​​the end of the sound tube away from the front cavity is a second cross-sectional area. The first cross-sectional area is smaller than the second cross-sectional area.

[0006] In some embodiments, the cross-sectional area of ​​the sound tube in its extension direction gradually increases from one end near the front cavity to the other end away from the front cavity.

[0007] In some embodiments, the wall curvature of the sound tube satisfies equation (8): (8) Among them, A (x) Let A1 be the first cross-sectional area at a distance x from the end of the sound tube closest to the front cavity, where x is the distance from the end of the sound tube closest to the front cavity, and A2 be the second cross-sectional area. The total length of the sound tube. The coefficient is 0.5 ≤ ≤2.0.

[0008] In some embodiments, the ratio of the first cross-sectional area to the second cross-sectional area is 1:1.2 to 1:5.

[0009] In some embodiments, the first cross-sectional area is 1 to 10 square centimeters; and / or, the second cross-sectional area is 3 to 30 square centimeters.

[0010] In some embodiments, the resonant device further includes a rear cavity disposed on the rear side of the speaker.

[0011] In some embodiments, the front cavity is integrally formed with the sound tube.

[0012] In some embodiments, the cross-section of the sound tube is circular, elliptical, racetrack-shaped, trapezoidal, or rectangular.

[0013] In some embodiments, the extension direction of the sound tube is curved.

[0014] This application embodiment also provides a speaker, including: case; A resonance device, wherein the resonance device is the aforementioned resonance device, and the resonance device is disposed within the housing.

[0015] The resonant device and speaker provided in this application allow for adjustment of the equivalent sound wave path by increasing the cross-sectional area of ​​the sound tube. With a constant sound velocity, adjusting the equivalent sound wave path adjusts the fundamental frequency accordingly to suit different scenarios. Furthermore, changing the cross-section of the sound tube effectively increases the output sound pressure level without increasing the size of the resonant device, enabling efficient acoustic performance in a miniaturized design. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the first structure of the resonance device provided in the embodiments of this application.

[0018] Figure 2 This is a schematic diagram of a second structure of the resonance device provided in an embodiment of this application.

[0019] Figure 3 This is a schematic diagram of a third structure of the resonance device provided in the embodiments of this application.

[0020] Figure 4 A comparison diagram of frequency response curves provided for embodiments of this application.

[0021] Figure 5 This is a schematic diagram of the resonant structure provided in an embodiment of this application.

[0022] Figure 6 A comparison diagram of the frequency response and impedance of the resonant structure and resonant device provided in the embodiments of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application 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 this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] This application provides a resonance device and a speaker enclosure, which can meet the requirements of loudness enhancement and miniaturization. The following is a detailed description with reference to the accompanying drawings.

[0025] Please see Figure 1 , Figure 1 This is a schematic diagram of the first structure of the resonance device provided in the embodiments of this application.

[0026] This application provides a resonance device 100. The resonance device 100 includes a loudspeaker 10, a front cavity 20, and a sound tube 30.

[0027] The loudspeaker 10, also known as a horn or electroacoustic transducer, is a transducer that converts electrical signals into sound signals. The loudspeaker 10 can convert audio electrical signals into corresponding sound signals and is the most basic component of a speaker system, serving as the source of sound generation in the resonant device 100.

[0028] In the acoustic structure, the front cavity 20 is located on the front side of the speaker 10, which plays a preliminary guiding and focusing role on the sound waves emitted by the speaker 10. It can affect the initial propagation characteristics of the sound waves and lay the foundation for the subsequent propagation and adjustment of the sound waves in the sound tube 30.

[0029] When the sound wave is emitted from the speaker 10, it first enters the front cavity 20. The specific spatial shape and size of the front cavity 20 can change the propagation direction and distribution of the sound wave, making the sound wave propagate forward more concentratedly, laying the foundation for the propagation and adjustment of the subsequent sound wave in the sound tube 30.

[0030] The sound tube 30 is a pipe structure connected to the front cavity 20 and is a key component in the resonance device 100 for further adjusting the propagation path and characteristics of sound waves. Its unique shape and size design directly affect the way sound waves propagate within it, thereby changing the frequency, loudness, and other characteristics of the sound.

[0031] The sound tube 30 is connected to the side of the front cavity 20 away from the speaker 10. The sound tube 30 is connected to the front cavity 20, so that the sound waves can smoothly enter the sound tube 30 from the front cavity 20, thus realizing the continuation of the sound wave propagation path.

[0032] The cross-sectional area of ​​the end of the sound tube 30 closest to the front cavity 20, i.e., the initial cross-sectional area, is the first cross-sectional area. The cross-sectional area of ​​the end of the sound tube 30 furthest from the front cavity 20, i.e., the sound outlet, is the second cross-sectional area. The first cross-sectional area is smaller than the second cross-sectional area. This design of increasing the cross-sectional area of ​​the sound tube 30 can also adjust the fundamental frequency and increase the output sound pressure level.

[0033] There is a certain relationship between the fundamental frequency and the path length of the sound wave, according to equation (1): (1) in, This is the speed at which sound waves propagate in a medium (approximately 343 m / s). For the position of manager.

[0034] As can be seen from equation (1) above, the equivalent path growth (i.e. Increasing the frequency will lower the fundamental frequency and reduce the equivalent path length (i.e., Reducing the fundamental frequency (of a sound) will raise the fundamental frequency. The fundamental frequency is the basic frequency of sound and determines the pitch of the sound. A lower fundamental frequency means a lower pitch, and a higher fundamental frequency means a higher pitch.

[0035] Taking the sound tube 30 as a conical tube model as an example, according to the acoustic transmission line theory, the equivalent resonant tube length of the sound tube 30 satisfies equation (2): (2) in, The equivalent tube length of the sound tube is 30. A1 is the actual length of the sound tube 30. A2 is the cross-sectional area of ​​the end of the sound tube 30 closest to the front cavity 20, i.e., the first cross-sectional area mentioned above. A2 is the cross-sectional area of ​​the end of the sound tube 30 furthest from the front cavity 20, i.e., the second cross-sectional area mentioned above.

[0036] Combining equations (1) and (2), it can be seen that, with the first cross-sectional area A1 remaining unchanged, changing the second cross-sectional area A2 can adjust the fundamental frequency of the resonant device 100, thereby optimizing the low-frequency performance without changing the actual tube length, so as to adapt to different scenarios.

[0037] For example, space is often limited in multimedia speakers, soundbars, or portable Bluetooth speakers. By adjusting the outlet area of ​​the sound tube (second cross-sectional area A2), bass performance can be enhanced without increasing the product size, adapting to different structural designs and acoustic requirements.

[0038] For example, in car audio systems, the acoustic environment inside a vehicle is complex, and the space for speaker installation is strictly limited. By adjusting the outlet area of ​​the sound tube (the second cross-sectional area A2), low-frequency tuning can be performed on the cavity space of a specific car model, improving bass output efficiency and sound quality.

[0039] Please continue reading. Figure 1 This application proposes a sound tube 30 with a gradient cross-sectional area, meaning that the cross-sectional area of ​​the sound tube 30 gradually increases from the end closer to the front cavity 20 to the end farther away from the front cavity 20 along its extension direction. This design achieves a smooth impedance change encountered during sound wave propagation, reduces sound energy reflection caused by impedance abrupt changes, improves sound wave transmission efficiency, effectively increases the sound pressure level, and reduces the Q value. Here, the extension direction refers to the length direction of the sound tube 30 from one end to the other, i.e., the direction in which sound propagates within the sound tube 30. The Q value is an important parameter for measuring the frequency selectivity of an acoustic system. The gradient cross-sectional area design of the sound tube 30 helps to reduce the Q value of the resonant device 100 by changing the sound wave propagation path and impedance characteristics. The gradient cross-sectional area design of the sound tube 30 reduces sound wave reflection, interference, and distortion during propagation by optimizing the sound wave propagation path and impedance matching.

[0040] The increase in sound pressure level caused by the change in the cross-sectional area of ​​the sound tube 30 can be derived by the following equations (3) to (7): (3) in, For radiation impedance, For radiation resistance, For radiation resistance, Let A be the wave number and A be the cross-sectional area.

[0041] (4) Where U is the volume velocity. Let A be the speed of sound in the medium (approximately 343 m / s), and let A be the cross-sectional area.

[0042] (5) SPL stands for Sound Pressure Level, which is a physical quantity that measures the intensity of sound, and its unit is decibel (dB).

[0043] In the low-frequency range, since k is extremely small, the radiation resistance is extremely small, and the main effect is the radiation impedance. SPL (Sound Pressure Level) can be equivalent to the following equation (6): (6) The increase in loudness resulting from the change in cross-sectional area is equivalent to the following equation (7): (7) Where A1 is the first cross-sectional area and A2 is the second cross-sectional area.

[0044] Therefore, since the second cross-sectional area is larger than the first cross-sectional area, the change in the cross-sectional area of ​​the sound tube 30 in this application can effectively increase the sound pressure level (loudness) without increasing the physical volume.

[0045] As the cross-sectional area of ​​the sound tube 30 gradually changes, the curvature of the tube wall of the sound tube 30 satisfies equation (8): (8) Among them, A (x) Let A1 be the first cross-sectional area at a distance x from the end of the sound tube 30 closest to the front cavity 20, where x is the distance from the end of the sound tube 30 closest to the front cavity 20, and A2 be the second cross-sectional area. Let be the total length of the sound tube 30, and k0 be a coefficient that satisfies 0.5≤k0≤2.0. For example, k0 can be 0.5, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.5, 1.7, 1.8 or 2.0.

[0046] The total length of the sound tube 30 is 0.8m to 2m, which can form a good matching relationship with the sound wavelengths in the common audio range.

[0047] The ratio of the first cross-sectional area to the second cross-sectional area is between 1:1.2 and 1:5. When the ratio is as described above, the impedance change of sound propagation within the sound tube 30 is relatively gradual. If the ratio is too small, i.e., the difference in cross-sectional areas at both ends of the sound tube 30 is too large, the sound will encounter a large impedance jump when moving from the region with the smaller cross-sectional area to the region with the larger cross-sectional area. This results in strong reflection and scattering of the sound, leading to significant sound energy loss and decreased propagation stability. When the ratio is within the reasonable range described above, the sound can pass through the sound tube 30 more smoothly, reducing reflection and interference, thereby improving the stability of sound propagation.

[0048] The first cross-sectional area is between 1 and 10 square centimeters, which can match the acoustic characteristics of the loudspeaker 10 and the design of the front cavity 20. If the first cross-sectional area is too small, the sound will encounter greater resistance when entering the sound tube 30, resulting in greater sound energy loss, a significant reduction in loudness, and potentially alteration of the sound's frequency characteristics, leading to distortion. When the first cross-sectional area is between 1 and 10 square centimeters, it ensures that the sound smoothly enters the sound tube 30 from the loudspeaker 10, while simultaneously performing preliminary screening and adjustment of the sound's frequency components, giving the sound entering the sound tube 30 a better initial state and laying the foundation for subsequent propagation and optimization within the sound tube 30.

[0049] The second cross-sectional area, ranging from 3 to 30 square centimeters, creates a reasonable gradient with the first cross-sectional area, thereby optimizing sound propagation characteristics. If the second cross-sectional area is too small, not significantly different from the first, the sound tube 30's effect on sound diffusion and energy release is insignificant, limiting the improvement in sound propagation range and loudness. Conversely, if the second cross-sectional area is too large, the sound encounters a significant change in cross-sectional area as it propagates from the front to the back of the sound tube 30, resulting in strong reflection and scattering, deteriorating sound directivity, and potentially causing muddiness and unclear sound.

[0050] It is worth noting that, in this technical solution, the feature of gradually increasing cross-sectional area of ​​the sound tube 30 can be reflected in some sections of the sound tube 30 or can be extended to all sections of the sound tube 30.

[0051] When the gradual change in cross-sectional area of ​​the sound tube 30 exists only in certain sections (e.g., the initial section near the front cavity 20 or the final section far from the front cavity 20), its design aims to specifically optimize sound wave propagation within a specific frequency range. For example, using a gradual structure in the initial section can effectively reduce the fundamental frequency, while using a gradual structure in the final section can further smooth the amplitude-frequency response in the low-frequency band and suppress high-frequency harmonic distortion.

[0052] When the cross-sectional area of ​​the sound tube 30 gradually changes throughout its length (i.e., it changes continuously from one end near the front cavity 20 to the other), its design can achieve a more comprehensive improvement in acoustic performance.

[0053] In some cases, please refer to [the relevant documentation]. Figure 1 The cross-sectional area of ​​the front cavity 20 can be larger than the first cross-sectional area of ​​the sound tube 30, so that a throat is formed at the connection between the front cavity 20 and the sound tube 30. From the perspective of acoustic principles, the formation of the throat has a regulating effect on the propagation of sound waves, significantly improving the quality of sound.

[0054] In other cases, please refer to Figure 2 , Figure 2This is a schematic diagram of a second structure of the resonant device provided in an embodiment of this application. The cross-sectional area of ​​the front cavity 20 is the same as the first cross-sectional area of ​​the sound tube 30. When the cross-sectional areas of the two are the same, the sound wave will not undergo significant compression or expansion as it enters the sound tube 30 from the front cavity 20, resulting in smoother sound wave propagation and reduced reflection and interference losses caused by changes in cross-sectional area.

[0055] Therefore, the volume of the front cavity 20 can be set according to the correction or refinement of the sound waves, and there is no limitation here.

[0056] Please continue reading for more details. Figure 1 The front cavity 20 and the sound tube 30 are integrally molded, avoiding problems such as loosening and detachment that may occur due to component connections in traditional separate structures. During the use of the resonance device 100, the vibration of the speaker 10 generates a certain mechanical force. If the front cavity 20 and the sound tube 30 are separately connected, the connection points are prone to fatigue damage under long-term exposure to this force, leading to structural failure. The integrally molded structure can effectively disperse these mechanical forces, improving the vibration resistance and structural stability of the entire resonance device 100. At the same time, the integral molding process eliminates the connection gap between the front cavity 20 and the sound tube 30, fundamentally avoiding air leakage problems caused by gaps. The materials of the front cavity 20 and the sound tube 30 can be metal or plastic.

[0057] The sound tube 30 has a cross-section that is circular, elliptical, racetrack-shaped, trapezoidal, or rectangular. A circular cross-section sound tube 30 exhibits good symmetry, resulting in relatively uniform reflection and scattering of sound waves in all directions as they propagate within it. The fabrication processes for elliptical, racetrack-shaped, trapezoidal, and rectangular cross-sections are simpler. Furthermore, with increasing demands for miniaturization in acoustic devices, sound tubes 30 with elliptical, racetrack-shaped, trapezoidal, and rectangular cross-sections can achieve more efficient sound wave transmission within a limited space through rational layout and design.

[0058] Please see Figure 3 , Figure 3 This is a schematic diagram of a third structure of the resonant device provided in this application embodiment. The extension direction W of the sound tube 30 is curved. The curved sound tube 30 can increase the propagation path length of sound waves within the resonant device 100. The curved sound tube 30 design can achieve a longer sound wave propagation path within a limited space. Compared with a straight sound tube 30, the curved sound tube 30 can improve acoustic performance without increasing the overall volume of the resonant device 100 through reasonable design and layout.

[0059] Please continue reading. Figure 1 as well as Figure 2The resonant device 100 also includes a rear cavity 40 disposed on the rear side of the speaker 10. Specifically, the speaker 10 is sealed to the front end of the rear cavity 40, thereby separating the front side of the speaker 10 from the rear side. The front cavity 20 is sealed to the rear cavity 40, and the front cavity 20 also covers the front side of the speaker 10.

[0060] The rear cavity 40 provides a relatively enclosed acoustic environment for the vibration of the back of the speaker 10. When the back of the speaker 10 vibrates, it compresses or thins the air inside the rear cavity 40, producing a sound pressure change corresponding to the front vibration. By rationally designing the volume and shape of the rear cavity 40, this sound pressure change can be adjusted, thereby optimizing the frequency response of the sound.

[0061] Please see Figure 4 , Figure 4 A comparison diagram of frequency response curves provided for embodiments of this application. For the resonance device 100 in the above embodiments, this application also provides a comparison diagram of the frequency response curves of the resonance device 100 and the guide tube. The solid line represents the frequency response curve of the resonance device 100 provided in this application embodiment, and the dashed line represents the frequency response curve of the guide tube. From Figure 4 As can be seen, the resonant device 100 can effectively adjust the frequency band and loudness. In the ultra-low frequency range (20 Hz to 60 Hz), the frequency response curve of a traditional guide tube structure typically exhibits a relatively steep fourth-order slope; in contrast, the resonant device 100 of this application exhibits a gentler second-order slope in this frequency range. The lower the slope order and the gentler the curve, the more extended the low-frequency response or the lower the group delay characteristics of the system in this frequency range, which is beneficial to improving the naturalness of bass reproduction and the listening experience.

[0062] Therefore, the comparison confirms that the resonance device 100 of this application has better acoustic response characteristics in the ultra-low frequency region and can achieve a more stable and controllable low frequency enhancement effect.

[0063] The resonant structure 1 with a uniform cross-section will now be compared and described with the resonant device 100 in the embodiments of this application. Please refer to... Figure 5 , Figure 5 This is a schematic diagram of the resonant structure provided in an embodiment of this application. The resonant structure 1 includes a second loudspeaker 11, a second front cavity 12, and a second sound tube 13. The second front cavity 12 is disposed on the front side of the second loudspeaker 11, and the second sound tube 13 is connected to the side of the second front cavity 12 away from the second loudspeaker 11, and the second sound tube 13 communicates with the second front cavity 12. It should be particularly noted that the second sound tube 13 is a sound tube with a constant cross-section, that is, the cross-sectional area of ​​the second sound tube 13 is A1 at all points.

[0064] Please see Figure 6 , Figure 6A comparison diagram of the frequency response and impedance of the resonant structure and resonant device provided in the embodiments of this application. Figure 6 In the diagram, the solid line represents the frequency response curve of the resonant device 100 provided in the embodiments of this application, and the dashed line represents the frequency response curve of the resonant structure 1 described above. From Figure 6 As can be seen, the resonance device 100 can increase loudness, and the increase in loudness is proportional to the increase in area.

[0065] This application also provides a speaker. The speaker includes a housing and a resonant device 100. The housing serves as the external structure of the speaker, protecting the internal components. The resonant device 100 is the same as the one described in the above embodiments, and it is disposed within the housing. The speaker provided in this application, through the coordinated operation of the housing and the resonant device 100, achieves optimized sound propagation, improved frequency response, and enhanced overall performance.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0067] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0068] The resonant device and speaker provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A resonant device, characterized in that, include: speaker; The front cavity is located on the front side of the speaker; A sound tube is connected to the side of the front cavity away from the speaker. The sound tube communicates with the front cavity. The cross-sectional area of ​​the end of the sound tube near the front cavity is a first cross-sectional area, and the cross-sectional area of ​​the end of the sound tube away from the front cavity is a second cross-sectional area. The first cross-sectional area is smaller than the second cross-sectional area.

2. The resonance device according to claim 1, characterized in that, The cross-sectional area of ​​the sound tube in its extension direction gradually increases from one end closer to the front cavity to the other end farther away from the front cavity.

3. The resonance device according to claim 2, characterized in that, The curvature of the pipe wall satisfies equation (8): （8） Among them, A (x) Let A1 be the first cross-sectional area at a distance x from the end of the sound tube closest to the front cavity, where x is the distance from the end of the sound tube closest to the front cavity, and A2 be the second cross-sectional area. The total length of the sound tube. The coefficient is 0.5 ≤ ≤2.

0.

4. The resonant device according to any one of claims 1 to 3, characterized in that, The ratio of the first cross-sectional area to the second cross-sectional area is 1:1.2 to 1:

5.

5. The resonance device according to claim 4, characterized in that, The first cross-sectional area is 1 to 10 square centimeters; and / or the second cross-sectional area is 3 to 30 square centimeters.

6. The resonant device according to any one of claims 1 to 3, characterized in that, It also includes a rear cavity, which is disposed on the rear side of the speaker.

7. The resonant device according to any one of claims 1 to 3, characterized in that, The front cavity is integrally formed with the sound tube.

8. The resonant device according to any one of claims 1 to 3, characterized in that, The cross-section of the sound tube is circular, elliptical, racetrack-shaped, trapezoidal, or rectangular.

9. The resonant device according to any one of claims 1 to 3, characterized in that, The extension direction of the sound tube is curved.

10. A speaker, characterized in that, include: case; A resonance device, wherein the resonance device is the resonance device according to any one of claims 1 to 9, and the resonance device is disposed within the housing.

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