Multi-unit sound production device

Abstract

The invention discloses a multi-unit sound production device, which comprises a plurality of sound production units and a passive sound production module, wherein at least one sound production unit is connected with a resonant cavity through a sound guide tube, and the resonant cavity is further connected to the passive sound production module to form an acoustic excitation path in which the low-frequency-band sound production unit drives the extremely-high-frequency-band passive sound production module; the plurality of sound production units and the passive sound production module are respectively connected to an auditory meatus outlet through respective sound guide tubes; the resonant cavity is arranged to be of a micro-cavity structure so as to be matched with the acoustic impedance of the passive sound production module in a specific extremely high frequency band response range. According to the invention, a cross-band acoustic feedback coupling mechanism is established by introducing a sound guide channel and a resonant cavity structure between the sound production unit and the passive unit, and dynamic regulation and control and frequency response optimization of frequency band sound energy are realized on the premise of not influencing normal output of an original active loudspeaker.

Description

Technical Field

[0001] The present invention belongs to the technical field of loudspeakers, and in particular relates to a multi-unit sound-emitting device. Background Art

[0002] As people's requirements for the sound quality of audio equipment continue to increase, the development of headphones and in-ear monitoring systems tends to be more refined and high-fidelity, especially in the ultra-high frequency segment (above 20kHz). In traditional multi-unit acoustic structures, multiple active speakers are usually used to cover the low frequency, mid-high frequency and ultra-high frequency segments respectively, and full-frequency response is achieved through electronic circuits. However, it is difficult to control the energy of the active unit in the ultra-high frequency area, and it is easy to have excessive energy or peak offset, resulting in harsh or unnatural listening. In addition, the wavelength of ultra-high frequencies is extremely short and is highly sensitive to the system structure and sound wave propagation path. The slightest inappropriateness may cause standing waves, interference or high-frequency distortion.

[0003] In order to improve the naturalness and balance of the ultra-high frequency response, some solutions introduce passive radiation units (passive speakers) and use their structural resonance characteristics to compensate or suppress high frequencies. However, conventional passive radiators rely on large-mass flexible diaphragms to achieve low-frequency resonance (such as the bass reflex tube design), but cannot meet ultra-high frequency requirements. If it is directly coupled with an ultra-high frequency speaker or a mid-to-high frequency unit, it may also interfere with the output path of the active sound source itself, causing high-frequency signal distortion. Although the moving iron unit has high-frequency potential, its electromagnetic drive structure results in a large size and high power consumption, making it difficult to directly apply to micro-passive scenarios.

[0004] In addition, the cross-frequency speaker method of achieving full-frequency response is prone to high-frequency acoustic impedance mismatch. For example, the standing waves and resonant peaks of the micro-cavity will interfere with the transmission of ultra-high-frequency sound energy, causing the ultra-high-frequency curve to be non-linear and the actual listening experience to be not smooth and soft.

[0005] Therefore, how to effectively control ultra-high frequency energy without destroying the original frequency band output has become an important technical issue in audio system design.

[0006] The information disclosed in the above background technology section is only intended to increase the understanding of the overall background of the present invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0007] The purpose of the present invention is to provide a multi-unit sound-emitting device. By introducing a sound-conducting path and a resonant cavity structure between the sound-emitting unit and the passive unit, a cross-band acoustic feedback coupling mechanism is established to achieve dynamic control of the frequency band sound energy and frequency response optimization without affecting the normal output of the original active speaker.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A multi-unit sound-emitting device comprises a plurality of sound-emitting units and a passive sound-emitting module; wherein, at least one sound-emitting unit is connected to a resonant cavity via a sound-conducting tube, and the resonant cavity is further connected to the passive sound-emitting module, forming an acoustic excitation path in which a low-frequency-band sound-emitting unit drives an extremely high-frequency-band passive sound-emitting module; the plurality of sound-emitting units and the passive sound-emitting module are respectively connected to the ear canal outlet via their respective sound-conducting tubes; the resonant cavity is configured as a micro-cavity structure to match the acoustic impedance of the passive sound-emitting module in a specific extremely high-frequency-band response range.

[0010] Specifically, the sound-emitting unit includes a low-frequency speaker, a mid-high-frequency speaker, and an extremely high-frequency speaker, and the passive module includes an extremely high-frequency passive speaker.

[0011] Specifically, the sound guide tube and the resonance cavity form a closed or semi-open acoustic passage for transmitting low-frequency sound pressure without introducing air leakage.

[0012] Specifically, the ultra-high frequency passive speaker has a response characteristic in the ultra-high frequency band that is opposite in phase to the output of the ultra-high frequency speaker, thereby forming acoustic negative feedback to suppress excessive ultra-high frequency energy.

[0013] Specifically, the resonant cavity includes a plurality of stepped and interconnected microcavities arranged at the bottom of the ultra-high frequency passive speaker. The volume, small hole size, sound guide tube length and cross-sectional shape of the resonant cavity are tuned to form standing wave resonance for the passive sound module in a specific ultra-high frequency band response range.

[0014] Specifically, it also includes an upper shell and a lower shell, and the upper shell and the lower shell are connected in a nested manner; the lower shell is provided with a limiting platform, and the limiting platform separates the earphone shell into a front cavity and a rear cavity, and the limiting platform is provided with a groove for installing a sound unit and a passive sound module.

[0015] Specifically, the low-frequency loudspeaker is further provided with a pressure relief channel, which is communicated with the outside through the rear cavity.

[0016] Specifically, the ultra-high frequency passive speaker includes a left shell, a dome, a diaphragm, a diaphragm bracket, a right shell, a sound outlet, a circuit board, and solder points; the dome is fixed to the diaphragm by gluing, and the diaphragm is fixed to the diaphragm bracket by gluing; the diaphragm bracket is bonded to the left shell, the left shell and the right shell are laser welded, the sound outlet is fixed to the front end of the shell by gluing, and the welding board is welded to the shell, and the welding board has welding points on its surface.

[0017] The technical principle of this solution is: the low-frequency speaker in this solution is connected to the ultra-high frequency passive speaker through a sound guide tube and a resonant cavity, and the structural excitation force and large energy characteristics of the low-frequency system are used to form a cross-band coupling system. Its main purpose is not to let the low frequency drive the ultra-high frequency response, but to use the large dynamic drive and resonance characteristics of the low-frequency unit to stimulate the sound pressure changes in the connecting tube and the cavity; then the ultra-high frequency response is regulated by the micro-cavity through the acoustic impedance matching formula, so that the passive unit can respond to the ultra-high frequency band range; after the passive unit responds, anti-phase coupling is generated. On the one hand, the frequency response curve is made more linear in the frequency band of 8kHz-20kHz. At the same time, with the help of the phase delay characteristics of the resonant cavity, on the other hand, a certain negative feedback path is formed above 10kHz-20kHz to partially offset the energy of the over-boosted ultra-high frequency, thereby achieving balanced control of the acoustic output in the ultra-high frequency band.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. When the frequency response of the present invention is compared with that of the prior art under professional test instruments, a more obvious linear change is produced in the ultra-high frequency band, and due to the negative feedback effect, the excessive ultra-high frequency is reduced; thus, the excessive or unnatural ultra-high frequency in the system is controlled, and the sound is more balanced and natural.

[0020] 2. The passive unit is tuned by using micro-cavity acoustic impedance matching to enable it to obtain effective energy coupling in the ultra-high frequency band, thereby extending its effective operating frequency to 40kHz, making up for the defect that traditional passive units cannot cover ultra-high frequencies.

[0021] 3. The present invention realizes the coordinated regulation between active and passive units through cross-band structural design, improves the system's control ability of ultra-high frequency signals, and does not introduce additional electronic filtering or modulation paths. It has the advantages of simple structure, low cost, natural sound, smooth frequency response, etc., and is suitable for high-fidelity headphones, in-ear monitoring equipment and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a perspective view of a multi-unit sound-emitting device of the present invention.

[0023] Figure 2 This is a schematic diagram of an explosion of a multi-unit sound-generating device of the present invention.

[0024] Figure 3 It is a top view of the lower shell of the present invention.

[0025] Figure 4 This is a first cross-sectional view of the lower shell of the present invention.

[0026] Figure 5 This is a second cross-sectional view of the lower shell of the present invention.

[0027] Figure 6 This is a schematic diagram of the explosion of the ultra-high frequency passive loudspeaker of the present invention.

[0028] Figure 7 This is a comparison diagram of the frequency response of the present invention and the prior art.

[0029] In the figure, 1-upper shell; 2-lower shell; 3-ultra-high frequency speaker; 4-ultra-high frequency passive speaker; 5-female socket; 6-resonant cavity; 7-crossover circuit board; 8-low frequency speaker; 9-mid-high frequency speaker; 10-41-left shell; 42-dome; 43-diaphragm; 44-diaphragm bracket; 45-right shell; 46-sound outlet; 47-circuit board; 48-solder point. DETAILED DESCRIPTION

[0030] To explain the technical content, objectives, and effects of the present invention in detail, the following embodiments are described in conjunction with the accompanying drawings. In the description of this embodiment, it should be understood that the terms indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only used to facilitate the description of this embodiment and simplify the description. They do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0031] The technical solution adopted in this embodiment is a multi-unit sound-emitting device, such as Figure 1-7 As shown, the multi-unit sound-emitting device of this embodiment includes an upper shell 1 and a lower shell 2, which are connected in a nested manner to form a complete cavity structure, and a female seat 5 is provided between the upper shell 1 and the lower shell 2. The lower shell 2 is provided with a limiting platform for dividing the internal space of the device into a front cavity and a rear cavity; the limiting platform is provided with a plurality of grooves for installing the sound-emitting unit and the passive sound-emitting module, and the sound-emitting unit and the passive sound-emitting module are fixed therein by glue to achieve precise positioning and stable fixation of the acoustic unit. A frequency division circuit board 7 is also provided above the limiting platform, and the female seat 5, the sound-emitting unit, and the passive sound-emitting module are all connected to the frequency division circuit board 7.

[0032] like Figure 3-5As shown, the device of this embodiment integrates three active sound-generating units: a low-frequency speaker 8, a mid-high-frequency speaker 9, and an ultra-high-frequency speaker 3, each of which is used to output sound wave signals in its corresponding frequency band. In addition, it also includes an ultra-high-frequency passive speaker 4, which is not directly driven by an electrical signal, but instead resonates due to sound pressure excitation, thereby forming an additional acoustic response in the ultra-high frequency band. Furthermore, the ultra-high-frequency passive speaker 4 has a response characteristic in a specific ultra-high frequency band that is opposite in phase to the output of the ultra-high-frequency speaker 3. The diaphragm mass, edge compliance, and cavity coupling parameters of the ultra-high-frequency passive speaker 4 are designed to adapt to ultra-short wavelength sound waves, thereby improving its acoustic response sensitivity in this specific ultra-high frequency band.

[0033] In this embodiment, reference Figure 1 As shown, the output ends of each active speaker and ultra-high frequency passive speaker are connected to the ear canal outlet of the device through independent sound guide tubes to achieve synchronous transmission of multi-band sounds and reduce interference between sound waves.

[0034] The low-frequency speaker 8 is connected to the resonant cavity 6 via a sound guide tube. The sound guide tube and the resonant cavity form a closed or semi-open acoustic path. The resonant cavity is a group of micro-cavity structures arranged in a stepped manner and interconnected to form a Helmholtz resonant cavity. According to the Helmholtz resonator principle formula:

[0035] Where: c: speed of sound; A: neck cross-sectional area; V: cavity volume; Leff: effective neck length. The acoustic impedance matching formula allows the resonant cavity volume, aperture size, sound guide tube length, and cross-sectional shape to be controlled, creating standing wave resonance within the passive sound module's specific ultra-high frequency response range. This microcavity structure is designed to generate standing waves within a specific frequency band and achieve structural acoustic impedance matching with the passive speaker, adjusting its acoustic response. The distributed resonant cavity 6 is further connected to the ultra-high frequency passive speaker 4, forming an acoustic excitation path.

[0036] During operation, when the low-frequency speaker 8 emits sound waves, air pressure fluctuations are generated through the sound guide tube and the resonant cavity. These fluctuations excite the diaphragm 43 of the ultra-high frequency passive speaker 4 into resonance. The passive speaker can provide effective acoustic response in a frequency range up to 40 kHz. The reason is: first, the low-frequency speaker itself emits sound waves across the entire frequency range. The filter and sound guide tube cannot completely filter out ultra-high frequency sound waves, so ultra-high frequency sound waves still pass through the tube to reach the passive speaker and the human ear. Second, the passive ultra-high frequency speaker does not require ultra-high frequency sound waves to be driven; low-frequency fluctuations can also drive the diaphragm and air inside it to vibrate, thus forming resonance. The sound emitted by all speakers, including the ultra-high frequency passive speaker, is transmitted to the human ear through the sound guide tube. The sounds will affect each other. By controlling the size of the passive ultra-high frequency speaker, the diameter and length of the sound guide tube, etc., the resonant frequency can be controlled within a certain ultra-high frequency range, thereby suppressing or enhancing the ultra-high frequency in this frequency range. In this embodiment, the effect is suppression, suppressing some excessive ultra-high frequency and optimizing the overall listening experience.

[0037] It is worth noting that the reference Figure 6 As shown, the ultra-high frequency passive speaker 4 adopts a moving iron structure, and its interior includes a left shell 41, a dome 42, a diaphragm 43, a diaphragm bracket 44, a right shell 45, a sound outlet 46, a circuit board 47, and solder joints 48. The dome 42 is connected to the diaphragm 43 by a gluing process, and the diaphragm is bonded to the diaphragm bracket 44, and the diaphragm bracket is bonded to the left shell 41. The right shell 45 and the left shell 41 are sealed by laser welding. The sound outlet 46 is fixed to the front end of the right shell by gluing, and the sound waves are output from here. The circuit board 47 is welded to the right shell and has multiple solder joints 48.

[0038] In order to further improve the stability of the system, the low-frequency speaker 8 is also provided with a pressure relief channel, which is connected to the rear cavity of the lower shell and then connected to the outside world through the rear cavity. It is used to release part of the air pressure generated in its back cavity during operation to prevent the diaphragm from being offset, nonlinear vibration or even damaged due to the accumulation of air pressure.

[0039] The frequency response comparison between this embodiment and the prior art is shown in the figure below. Figure 7 As shown in the figure, the frequency response under professional test instruments is compared, and a more obvious change occurs in the ultra-high frequency band. Due to the resonance effect of the ultra-high frequency passive unit in the ultra-high frequency range, its excessive ultra-high frequency is suppressed, and the frequency response is more linear.

[0040] Although the present invention has been described in detail above using specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made based on the present invention. Therefore, such modifications or improvements, which do not depart from the spirit of the present invention, are intended to fall within the scope of protection claimed herein.

Claims

1. A multi-unit sound-emitting device, characterized in that: It includes multiple sound-emitting units and a passive sound-emitting module; wherein, at least one sound-emitting unit is connected to a resonant cavity through a sound guide tube, and the resonant cavity is further connected to the passive sound-emitting module, forming an acoustic excitation path in which the low-frequency band sound-emitting unit drives the ultra-high-frequency band passive sound-emitting module; multiple sound-emitting units and passive sound-emitting modules are respectively connected to the ear canal outlet through their own sound guide tubes; the resonant cavity is set to a micro-cavity structure to match the acoustic impedance of the passive sound-emitting module in the specific ultra-high-frequency band response range.

2. A multi-unit sound-emitting device according to claim 1, characterized in that: The sound-generating unit includes a low-frequency speaker, a mid-high-frequency speaker, and an extremely high-frequency speaker, and the passive module includes an extremely high-frequency passive speaker.

3. A multi-unit sound-emitting device according to claim 1, characterized in that: The sound guide tube and the resonance cavity form a closed or semi-open acoustic passage.

4. A multi-unit sound-emitting device according to claim 2, characterized in that: The ultra-high frequency passive speaker has a response characteristic in a specific ultra-high frequency band that is opposite in phase to the output of the ultra-high frequency speaker.

5. The multi-unit sound-emitting device according to claim 1, characterized in that: The resonant cavity includes a plurality of stepped and interconnected microcavities arranged at the bottom of the ultra-high frequency passive speaker. The volume, small hole size, sound guide tube length and cross-sectional shape of the resonant cavity are tuned to form standing wave resonance in the passive sound module's response range in a specific ultra-high frequency band.

6. A multi-unit sound-generating device according to claim 2, characterized in that: It also includes an upper shell and a lower shell, which are connected in a nested manner; the lower shell is provided with a limiting platform, which separates the earphone shell into a front cavity and a rear cavity, and the limiting platform is provided with a groove for installing a sound unit and a passive sound module.

7. A multi-unit sound-emitting device according to claim 6, characterized in that: The low-frequency loudspeaker is further provided with a pressure relief channel, which is communicated with the outside world through the rear cavity.

8. A multi-unit sound-emitting device according to claim 2, characterized in that: The ultra-high frequency passive speaker includes a left shell, a dome, a diaphragm, a diaphragm bracket, a right shell, a sound outlet, a circuit board, and solder points; the dome is fixed to the diaphragm by gluing, and the diaphragm is fixed to the diaphragm bracket by gluing; the diaphragm bracket is bonded to the left shell, the left shell and the right shell are laser welded, the sound outlet is fixed to the front end of the shell by gluing, and the welding board is welded to the shell, and the welding board has welding points on its surface.

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