A dynamic loudspeaker based on a Helmholtz resonant cavity

Abstract

This utility model discloses a dynamic loudspeaker based on a Helmholtz resonant cavity, including a frame. A diaphragm voice coil assembly is mounted on one side of the frame, and a magnet is provided at the bottom of the diaphragm voice coil assembly. A U-shaped iron and a rear cover are installed inside the frame. The rear cover is fitted onto the outside of the U-shaped iron. A resonant cavity is provided on the opposite side of the rear cover and the U-shaped iron. A U-shaped iron vent hole is formed around the U-shaped iron, and the vent hole connects the resonant cavity and the inner cavity of the U-shaped iron. A U-shaped iron rib is provided on the surface of the U-shaped iron, and the U-shaped iron rib is connected to the inner wall of the rear cover. This utility model has the advantage of smooth air discharge, solving the problem that existing dynamic loudspeakers are not easy to improve the air discharge from the rear cavity of the diaphragm during use. When the diaphragm vibration amplitude is too large, it is easy to cause unsmooth air discharge and diaphragm vibration imbalance.

Description

Technical Field

[0001] This utility model relates to the field of loudspeaker technology, specifically to a moving-coil loudspeaker based on a Helmholtz resonant cavity. Background Technology

[0002] A moving-coil loudspeaker, also known as an electrodynamic loudspeaker, is a type of loudspeaker that operates based on electromagnetic principles. It is the most common loudspeaker design and is widely used in various audio equipment. Its basic working principle is based on the magnetic field generated by an electric current passing through a coil. This magnetic field interacts with the magnetic field of a permanent magnet, causing a diaphragm connected to the coil to vibrate, thereby pushing air to produce sound. Specifically, the audio signal enters the voice coil in the loudspeaker unit in the form of an electric current. The voice coil is located in the magnetic field of a fixed magnetic circuit system. As the audio current changes, the voice coil generates a corresponding changing magnetic field. This changing magnetic field interacts with the constant magnetic field generated by the permanent magnet, causing the voice coil and its connected diaphragm to vibrate, thus generating sound waves. When the diaphragm operates, it compresses the air inside the loudspeaker, so vent holes are provided on the loudspeaker to prevent the increased internal pressure from affecting the diaphragm's vibration.

[0003] Existing dynamic loudspeakers do not make it easy to improve the air discharge from the rear cavity of the diaphragm during use. When the diaphragm vibration amplitude is too large, it is easy to cause the air discharge to be obstructed, resulting in an unbalanced diaphragm vibration. Utility Model Content

[0004] The purpose of this invention is to provide a moving-coil loudspeaker based on a Helmholtz resonant cavity, which has the advantage of smooth air exhaust. This solves the problem that existing moving-coil loudspeakers are not easy to improve the air exhaust in the rear cavity of the diaphragm during use, and when the diaphragm vibration amplitude is too large, it is easy to cause unsmooth air exhaust and diaphragm vibration imbalance.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a dynamic loudspeaker based on a Helmholtz resonant cavity, comprising a frame, a diaphragm voice coil assembly mounted on one side of the frame, a magnet provided at the bottom of the diaphragm voice coil assembly, a U-shaped iron and a rear cover mounted inside the frame, the rear cover being fitted over the outside of the U-shaped iron, a resonant cavity provided on the opposite side of the rear cover and the U-shaped iron, a U-shaped iron vent hole being provided around the U-shaped iron, the U-shaped iron vent hole connecting the resonant cavity and the inner cavity of the U-shaped iron, a U-shaped iron rib being provided on the surface of the U-shaped iron, the U-shaped iron rib being connected to the inner wall of the rear cover.

[0006] In a preferred embodiment of the moving-coil loudspeaker based on a Helmholtz resonant cavity according to this invention, the diameter of the U-shaped iron vent hole is 3-10 mm.

[0007] In a preferred embodiment of the moving-coil loudspeaker based on a Helmholtz resonant cavity according to this invention, the thickness of the U-shaped iron rib is 0.2-2mm.

[0008] As a preferred embodiment of the moving coil loudspeaker based on a Helmholtz resonant cavity according to this utility model, the number of U-shaped iron ribs is several and they surround the center of the U-shaped iron, and there are gaps between the adjacent U-shaped iron ribs.

[0009] As a preferred embodiment of the dynamic loudspeaker based on a Helmholtz resonant cavity according to this utility model, the magnet is fixedly installed inside the U-shaped iron, and a washer is fixedly connected to one side of the magnet. The washer and the magnet are located at the coil of the diaphragm voice coil assembly.

[0010] As a preferred embodiment of the dynamic loudspeaker based on a Helmholtz resonant cavity according to this utility model, the frame is provided with a frame vent hole, which is located in the rear cavity of the diaphragm voice coil assembly.

[0011] As a preferred embodiment of the moving coil loudspeaker based on a Helmholtz resonant cavity according to this utility model, a frame mesh is fixedly connected to the surface of the frame, and the frame mesh is located at the air outlet end of the frame vent hole.

[0012] As a preferred embodiment of the moving coil loudspeaker based on a Helmholtz resonant cavity according to this utility model, a central hole is provided at the center of the washer, magnet, U-shaped iron and the back cover.

[0013] As a preferred embodiment of the moving coil loudspeaker based on a Helmholtz resonant cavity according to this utility model, a central hole mesh is fixedly connected to the surface of the rear cover, and the central hole mesh is located at the air outlet end of the central hole.

[0014] As a preferred embodiment of the moving coil loudspeaker based on a Helmholtz resonant cavity according to this utility model, a solder pad is fixedly connected to the surface of the frame, and the solder pad is electrically connected to the diaphragm voice coil assembly.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. This invention significantly improves the sound quality in the low-frequency range by introducing the Helmholtz resonance principle. First, the Helmholtz resonant cavity can selectively absorb excess sound energy near its specific resonant frequency, which is particularly effective in solving the energy peak problem exhibited by speaker systems in certain low-frequency ranges. By adjusting the design parameters of the U-shaped iron vent and the U-shaped iron rib, the volume of the resonant cavity and the amount of air entering can be precisely controlled, thereby fine-tuning its resonant frequency to match the frequency range to be processed. As a result, the sound at these frequencies is smoother and more natural, reducing standing waves and distortion, and providing a clearer and more realistic audio experience. In addition, this design also helps to optimize the sound flow distribution in the magnetic gap, making it more uniform than ordinary designs, further improving the overall sound quality performance.

[0017] 2. This utility model effectively manages the airflow generated during diaphragm movement by using vent holes and mesh fabric on the frame and rear cover. The vent holes and central holes not only allow air to escape, avoiding additional distortion caused by air pressure changes, but also prevent dust and other impurities from entering the internal components, ensuring long-term stable performance. More importantly, by rationally designing the number of U-shaped iron ribs and the gaps between them, not only can the structural stability be enhanced, but the airflow path can also be adjusted, helping to create a more ideal acoustic environment. Therefore, this design not only improves the speaker's performance at key frequencies, but also enhances the reliability and durability of the entire system, providing users with a high-quality, durable, and reliable audio solution. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present utility model. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the structure of the present utility model. Figure 2 ;

[0020] Figure 3 This is an exploded view of the present invention;

[0021] Figure 4 This is a schematic diagram of the U-shaped iron of this utility model. Figure 1 ;

[0022] Figure 5 This is a schematic diagram of the U-shaped iron of this utility model. Figure 2 ;

[0023] Figure 6 This is a schematic diagram of the basin stand of this utility model;

[0024] Figure 7 This is a cross-sectional view of the present invention;

[0025] Figure 8 This is a cross-sectional view of a standard loudspeaker;

[0026] Figure 9 This is a simulation diagram of the acoustic flow of this utility model;

[0027] Figure 10 This is a simulation diagram of the acoustic flow of a conventional loudspeaker.

[0028] In the diagram: 1. Bass frame; 2. Diaphragm voice coil assembly; 3. Washer; 4. Magnet; 5. U-shaped iron; 6. Rear cover; 7. Bass frame mesh; 8. Solder pad; 9. Center hole mesh; 10. U-shaped iron vent hole; 11. U-shaped iron rib; 12. Gap; 13. Bass frame vent hole; 14. Center hole; 15. Resonance cavity. Detailed Implementation

[0029] Please see Figures 1-10 A dynamic loudspeaker based on a Helmholtz resonant cavity includes a frame 1, a diaphragm voice coil assembly 2 mounted on one side of the frame 1, a magnet 4 at the bottom of the diaphragm voice coil assembly 2, a U-shaped iron 5 and a rear cover 6 mounted inside the frame 1, the rear cover 6 being fitted over the outside of the U-shaped iron 5, a resonant cavity 15 being provided on the opposite side of the rear cover 6 and the U-shaped iron 5, a U-shaped iron vent hole 10 being provided around the U-shaped iron 5, the U-shaped iron vent hole 10 being connected to the resonant cavity 15 and the inner cavity of the U-shaped iron 5, and a U-shaped iron rib 11 being provided on the surface of the U-shaped iron 5, the U-shaped iron rib 11 being connected to the inner wall of the rear cover 6.

[0030] Furthermore, the diameter of the U-shaped vent hole 10 is 3-10mm.

[0031] Furthermore, the thickness of U-shaped reinforcing bar 11 is 0.2-2mm.

[0032] Furthermore, there are several U-shaped reinforcing bars 11 surrounding the center of the U-shaped iron 5, and gaps 12 are provided between adjacent U-shaped reinforcing bars 11.

[0033] Furthermore, magnet 4 is fixedly installed inside U-shaped iron 5, and washer 3 is fixedly connected to one side of magnet 4. Washer 3 and magnet 4 are located at the coil of diaphragm voice coil assembly 2.

[0034] Furthermore, a vent hole 13 is provided around the frame 1, and the vent hole 13 is located in the rear cavity of the diaphragm voice coil assembly 2.

[0035] Furthermore, a basin frame mesh 7 is fixedly connected to the surface of the basin frame 1, and the basin frame mesh 7 is located at the air outlet end of the basin frame vent hole 13.

[0036] Furthermore, a central hole 14 is provided at the center of the washer 3, magnet 4, U iron 5 and back cover 6.

[0037] Furthermore, a perforated mesh 9 is fixedly connected to the surface of the rear cover 6, and the perforated mesh 9 is located at the air outlet end of the perforated hole 14.

[0038] Furthermore, a solder pad 8 is fixedly connected to the surface of the frame 1, and the solder pad 8 is electrically connected to the diaphragm voice coil assembly 2.

[0039] Furthermore, the diaphragm voice coil assembly 2 is the core component of the dynamic loudspeaker. The diaphragm voice coil assembly 2 includes a diaphragm and a voice coil. The diaphragm is mounted on the top of the inner cavity of the frame 1. The diaphragm is responsible for converting the mechanical movement of the voice coil into sound waves, which push the air to produce sound. The voice coil generates a changing magnetic field when an audio current passes through it. This magnetic field interacts with the constant magnetic field generated by the magnet 4, driving the diaphragm to vibrate and produce sound. The voice coil is fitted onto the washer 3, which is located above the magnet 4. The washer 3 concentrates and guides the magnetic flux through the magnetic gap where the voice coil is located, improving the magnetic field efficiency. The magnet 4 provides a strong constant magnetic field. This magnetic field interacts with the magnetic field generated by the audio current flowing through the voice coil, causing the voice coil and the diaphragm connected to it to move and produce sound.

[0040] Furthermore, pad 8 is where electrical signals are input, transmitting external audio signals to the voice coil via soldering or direct connection. U-shaped iron 5 is located below magnet 4, helping to form a closed magnetic circuit and concentrating magnetic lines of force around the voice coil to enhance magnetic field strength. Rear cover 6 protects the internal components of the speaker from external environmental influences. Center hole mesh 9 covers the center hole 14 on the rear cover 6, and frame mesh 7 covers the frame vent 13 on the frame 1. Its main function is to prevent dust from entering the voice coil area and affecting its performance, while also having some impact on high-frequency response.

[0041] Furthermore, the resonant cavity 15 is a Helmholtz resonant cavity, which consists of a closed cavity and an opening connected to this cavity. The cavity is the side opposite to the U-shaped iron 5 and the back cover 6, and the opening is the central hole 14. Its working principle is based on the vibration of air at the central hole 14. When the sound wave reaches a specific frequency that matches the air volume and neck size in the cavity, the air column will vibrate at the neck, like a pendulum, causing energy to be absorbed and resonance to occur at that specific frequency. The Helmholtz resonant cavity can selectively absorb sound energy near its resonant frequency. This means that if a speaker system exhibits an excessively strong peak, i.e., excessive energy, in a certain low-frequency range, the excess sound energy can be absorbed by designing a Helmholtz resonant cavity at this frequency, thereby making the sound in this frequency range smoother and reducing standing waves and distortion.

[0042] When the diaphragm voice coil assembly 2 is working, the pad 8 transmits an electrical signal to the voice coil on the diaphragm voice coil assembly 2. The voice coil drives the diaphragm on the diaphragm voice coil assembly 2 to vibrate and produce sound. During the vibration of the diaphragm, it drives the air movement in its rear cavity. The air enters the basket vent 13 and the center hole 14 respectively. The air in the basket vent 13 is discharged through the basket mesh 7. The air in the center hole 14 enters the resonant cavity 15 through the gap 12 on the U-shaped iron rib 11, and is discharged to the outside through the center hole 14 and the center hole mesh 9 on the rear cover 6. During the air discharge process, excess sound energy is absorbed, making the sound in this frequency range smoother and reducing distortion. The volume of the resonant cavity 15 and the amount of air entering follow the size changes of the U-shaped iron vent 10 and the U-shaped iron rib 11, as shown by the formula. As can be seen, S is the cross-sectional area of ​​the channel, L is the channel length, and V is the volume of the Helmholtz resonant cavity. When the thickness of the U-shaped iron rib 11 increases, it is equivalent to increasing the channel length. Simultaneously, the volume V of the resonant cavity 15 also increases, thus changing the resonant frequency of the speaker. The diameter of the U-shaped iron vent 10 ranges from 3-10mm, and the thickness of the U-shaped iron rib 11 ranges from 0.2-2mm. When the thickness of the U-shaped iron rib 11 remains constant, increasing the diameter of the U-shaped iron vent 10 from 3-10mm increments results in a 3% to 10% increase in low-frequency response. When the diameter of the U-shaped iron vent 10 remains constant, increasing the diameter of the U-shaped iron rib 11 from 0.2-2mm increments results in a 2% to 10% increase in low-frequency response. (Reference) Figure 9 and Figure 10 The simulated cloud map shows that the acoustic flow of the magnetic gap in this invention is more uniform than that of ordinary ones.

[0043] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A moving-coil loudspeaker based on a Helmholtz resonant cavity, comprising a frame (1), wherein a diaphragm voice coil assembly (2) is mounted on one side of the frame (1), and a magnet (4) is provided at the bottom of the diaphragm voice coil assembly (2), characterized in that: The basin frame (1) is equipped with a U-shaped iron (5) and a back cover (6). The back cover (6) is fitted on the outside of the U-shaped iron (5). A resonant cavity (15) is provided on the opposite side of the back cover (6) and the U-shaped iron (5). A U-shaped iron vent hole (10) is provided around the U-shaped iron (5). The U-shaped iron vent hole (10) connects the resonant cavity (15) and the inner cavity of the U-shaped iron (5). A U-shaped iron rib (11) is provided on the surface of the U-shaped iron (5). The U-shaped iron rib (11) is connected to the inner wall of the back cover (6).

2. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The diameter of the U-shaped iron vent hole (10) is 3-10 mm.

3. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The thickness of the U-shaped reinforcing bar (11) is 0.2-2 mm.

4. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The number of U-shaped reinforcing bars (11) is several and they surround the center of the U-shaped iron (5), with gaps (12) between adjacent U-shaped reinforcing bars (11).

5. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The magnet (4) is fixedly installed inside the U-shaped iron (5), and a washer (3) is fixedly connected to one side of the magnet (4). The washer (3) and the magnet (4) are located at the coil of the diaphragm voice coil assembly (2).

6. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The frame (1) is provided with a frame vent (13) around it, and the frame vent (13) is located in the rear cavity of the diaphragm voice coil assembly (2).

7. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 6, characterized in that: The basin frame (1) is fixedly connected to a basin frame mesh (7), which is located at the air outlet end of the basin frame vent (13).

8. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 5, characterized in that: A central hole (14) is provided at the center of the washer (3), magnet (4), U iron (5) and back cover (6).

9. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 8, characterized in that: The rear cover (6) is fixedly connected with a perforated mesh (9), which is located at the air outlet end of the perforated hole (14).

10. A moving-coil loudspeaker based on a Helmholtz resonant cavity according to claim 1, characterized in that: The surface of the frame (1) is fixedly connected to a solder pad (8), which is electrically connected to the diaphragm voice coil assembly (2).

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