In-vehicle low-frequency vibrator and car audio system

Abstract

An in-vehicle low-frequency vibrator and a car audio system. The in-vehicle low-frequency vibrator includes a bracket, a magnetic circuit system having a magnetic gap, and a voice coil whose upper end is inserted into the magnetic gap and whose lower end is connected to the bracket. The in-vehicle low-frequency vibrator further includes a first positioning shim and a second positioning shim, each of which has an outer connecting edge, an inner connecting edge, and a woven main body connected between the outer and inner connecting edges. The first positioning shim has its outer connecting edge connected to the top of the bracket and its inner connecting edge connected to the top of the magnetic circuit system. The second positioning shim is located below the first positioning shim, and its outer connecting edge is connected to the bottom of the bracket and its inner connecting edge connected to the bottom of the magnetic circuit system. The in-vehicle low-frequency vibrator of the present disclosure has a low resonance frequency at low frequencies, which helps to create a better 4D effect in the vehicle.

Description

Cross-Reference to Related Art Applications

[0001] This application claims priority to Chinese patent applications filed on October 21, 2022, with application numbers CN202211296886X and CN2022227792466. [Technical Field]

[0002] The present disclosure relates to an in-vehicle low-frequency vibrator and a car audio system. [Background technology]

[0003] A low-frequency vibrator is installed in a car seat and emits low-frequency sounds and vibrations, thereby cooperating with a car audio system speaker (e.g., a door panel speaker) to create a 4D effect. The low-frequency vibrator includes a voice coil and a magnetic circuit system that provides a magnetic field to the voice coil. After the voice coil is powered on, it cooperates with the magnetic field of the magnetic circuit system to create an electromagnetic effect, causing the voice coil to reciprocate axially and output low-frequency sounds or vibrations. However, the voice coil may experience axial misalignment or axial vibration, which can degrade the output sound quality. Currently, a metal positioning shim is installed to prevent the voice coil from axial vibration. However, the structural stability of such a vibrator is still insufficient, making it impossible to lower the frequency of the sound. Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure relates to an in-car low-frequency vibrator and a car audio system that have a low resonance frequency at low frequencies and are useful for creating a better 4D effect inside a car. [Means for solving the problem]

[0005] In one aspect of the present disclosure, an in-vehicle low-frequency vibrator is provided, the in-vehicle low-frequency vibrator including a bracket, a magnetic circuit system having a magnetic gap, and a voice coil having an upper end inserted into the magnetic gap and a lower end connected to the bracket, Further comprising a first positioning shim and a second positioning shim, each of which has an outer connecting edge, an inner connecting edge, and a main body made of a woven fabric connected between the outer connecting edge and the inner connecting edge; the magnetic circuit system is at least partially located within the bracket; the first positioning shim has an outer connecting edge connected to the top of the bracket and an inner connecting edge connected to an upper portion of the magnetic circuit system; The second positioning shim is located below the first positioning shim, and the outer connecting edge of the second positioning shim is connected to the lower part of the bracket, and the inner connecting edge of the second positioning shim is connected to the lower part of the magnetic circuit system.

[0006] In some embodiments, the main body is flexible. The main body may be made of woven vegetable or synthetic fibers.

[0007] In some embodiments, the fabric is one or more combinations selected from the group consisting of cotton, linen, sieve cloth, COMEX, and blended fabrics.

[0008] In some embodiments, the main body of the first positioning shim has one or more rising and falling wave shapes, and the circular or geometric center of the wave shapes is located on the centerline of the voice coil.

[0009] In some embodiments, the main body of the second positioning shim has one or more rising and falling wave shapes, and the circular or geometric center of the wave shapes is located on the centerline of the voice coil.

[0010] In some embodiments, the outer connecting edge and the inner connecting edge of the first positioning shim and / or the second positioning shim are each horizontally disposed.

[0011] In some embodiments, the outer connecting edge and the inner connecting edge of the first positioning shim are on the same horizontal plane, and the horizontal plane is at the same height as the lowest point of the main body (specifically, the valley of the waveform) or lower than the lowest point of the main body.

[0012] In some embodiments, the outer connecting edge and the inner connecting edge of the second positioning shim are on the same horizontal plane, which is at the same height as the lowest point of the main body (specifically, the valley of the waveform) or lower than the lowest point of the main body.

[0013] In some embodiments, the bracket comprises a base plate for connection to a car seat, a first flange and a second flange extending upward from the base plate, the first flange surrounding the outer periphery of the second flange and being higher than the second flange, the second flange surrounding the outer periphery of the magnetic circuit system and the voice coil, the first positioning shim having an outer connecting edge fixedly connected to an upper surface of the first flange, and the second positioning shim having an outer connecting edge fixedly connected to an upper surface of the second flange.

[0014] In some embodiments, the magnetic circuit system includes a magnetic conductive part, a magnetic steel provided in the magnetic conductive part, and a front piece, the magnetic gap is formed between an inner surface of the magnetic conductive part and outer surfaces of the magnetic steel and the front piece, the first positioning shim has an inner connecting edge connected to an upper surface of the magnetic conductive part, and the second positioning shim has an inner connecting edge connected to a lower surface of the magnetic conductive part.

[0015] In some embodiments, the magnetic conductive part comprises a bottom and a cylindrical side wall extending downward from the edge of the bottom, the magnetic steel and the front piece are arranged in a space enclosed by the side wall, the first positioning shim has an inner connecting edge connected to an upper surface of the bottom of the magnetic conductive part, and the second positioning shim has an inner connecting edge connected to a lower surface of the side wall of the magnetic conductive part.

[0016] In some embodiments, the central portion of the base plate further comprises an upwardly extending boss, and the lower end of the voice coil is placed on the boss and fixedly connected to a side surface of the boss.

[0017] In some embodiments, the bracket is provided with bolts and / or an adhesive layer for connection to the car seat.

[0018] In some embodiments, the in-vehicle low-frequency vibrator further includes a terminal board disposed within the bracket and connected to a lead of the voice coil.

[0019] A second aspect of the present disclosure provides a car audio system including the above-described in-vehicle low-frequency vibrator, and further including one or more of a tweeter, a door panel speaker, and a headrest speaker.

[0020] In some embodiments, the in-vehicle low frequency vibrator is arranged to be attached to a sheet metal part of a car seat. [Effects of the Invention]

[0021] The present disclosure has the following advantages:

[0022] The in-vehicle low-frequency vibrator of the present disclosure uses two flexible positioning shims to connect the magnetic circuit system and the bracket, thereby having better structural stability, outputting better sound quality, avoiding axial displacement of the voice coil, and reducing the possibility of axial vibration of the voice coil, thereby obtaining a particularly low low-frequency resonance frequency (which can be as low as 60 Hz), and when applied to a car audio system, it can cooperate with other speakers in the car to create a better 4D effect.

[0023] In order to more clearly describe the technical solutions of the present disclosure, the following briefly describes the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art from these drawings without creative efforts. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic exploded view of an in-vehicle low-frequency vibrator according to a first embodiment of the present disclosure. [Figure 2] 1 is a plan view of an in-vehicle low-frequency vibrator according to a first embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 10 is a schematic exploded view of an in-vehicle low-frequency vibrator according to a second embodiment of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view of an in-vehicle low-frequency vibrator according to a second embodiment of the present disclosure. [Figure 6] FIG. 1 is a comparison diagram of impedance curves of speakers according to Example 1 and Comparative Example. DETAILED DESCRIPTION OF THE INVENTION

[0025] In order to facilitate understanding of the advantages and features of the present disclosure by those skilled in the art, preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the description of these embodiments contributes to understanding the present disclosure, but does not constitute a limitation on the present disclosure. In addition, the technical features of various embodiments of the present disclosure described below can be combined with each other unless they are mutually inconsistent.

[0026] In this disclosure, "inside" and "outside" are defined relative to the center line of the voice coil, with the side closer to the center line of the voice coil being the inside and vice versa. Words indicating directions such as "upper", "lower", and "horizontal" are used to help those skilled in the art easily understand the structure of the in-vehicle low-frequency vibrator, and are not intended to limit the state in which the in-vehicle low-frequency vibrator is mounted in a vehicle; for example, the in-vehicle low-frequency vibrator may be mounted on the underside of an inclined or upright member or member inside the vehicle.

[0027] This embodiment provides an in-vehicle low-frequency vibrator that is used in a car audio system and cooperates with speakers such as tweeters, door panel speakers, and headrest speakers to create a 4D effect. The in-vehicle low-frequency vibrator is installed in a car seat and outputs low-frequency sounds and vibrations.

[0028] 1 to 3 show an example of an in-vehicle low-frequency vibrator, which includes a bracket 1 having a cavity, a voice coil 2, and a magnetic circuit system 3, all of which are disposed within the cavity. The magnetic circuit system 3 has a magnetic gap, and the voice coil 2 has an upper end inserted into the magnetic gap and a lower end connected to the bracket 1; for example, the lower end of the voice coil 2 is glued to the bracket 1 with an adhesive. The voice coil 2 has a pair of positive and negative leads capable of supplying power and receiving audio signals. The in-vehicle low-frequency vibrator further includes a first positioning shim 4 and a second positioning shim 5, which connect the magnetic circuit system 3 to the inside of the bracket 1 and allow relative movement between the magnetic circuit system 3 and the bracket 1.

[0029] The first positioning shim 4 includes an outer connecting edge 41, an inner connecting edge 43, and a main body 42 connected between the outer connecting edge 41 and the inner connecting edge 43. The second positioning shim 5 includes an outer connecting edge 51, an inner connecting edge 53, and a main body 52 connected between the outer connecting edge 51 and the inner connecting edge 53. The main bodies 42 and 52 are made of woven fabric (cloth) and have a plurality of rising and falling wave shapes (ripples), and the circular or geometric center of the plurality of wave shapes is located on the center line of the voice coil 2. The main bodies 42 and 52 are made of flexible woven fabric formed by weaving vegetable fibers or synthetic fibers. Specifically, the main bodies 42 and 52 are cut from cloth (e.g., cotton, linen, sieve cloth, COMEX, or blended fabric, etc.) and then processed into a rising and falling wave shape. Positioning shims formed by weaving metal pieces or metal wires are not used. Furthermore, the first positioning shim 4 and the second positioning shim 5 are each integral and are cut out from a flexible woven fabric as a whole. In some other embodiments, the first positioning shim 4 and the second positioning shim 5 are manufactured by cutting a flexible woven fabric into the required ring shape, hemming the inner and outer edges, and then processing an up-and-down wave shape thereon.

[0030] At least a portion of the magnetic circuit system 3 is located within the bracket 1, and in this embodiment, the magnetic circuit system 3 is located entirely within the bracket 1, and when viewed from the side, the magnetic circuit system 3 is shielded by the bracket 1. The first positioning shim 4 has an outer connecting edge 41 connected to the top of the bracket 1, and an inner connecting edge 43 connected to the upper part of the magnetic circuit system 3. In this embodiment, the magnetic circuit system 3 is located entirely within the bracket 1, and its top is at the same height as the top of the bracket 1. The second positioning shim 5 is located below the first positioning shim 4, and has an outer connecting edge 51 connected to the bottom of the bracket 1, and an inner connecting edge 53 connected to the bottom of the magnetic circuit system 3.

[0031] Furthermore, the bracket 1 includes a base plate 10 for connection to a car seat, and a first flange 11 and a second flange 12 extending upward from the base plate 10, the first flange 11 surrounding the outer periphery of the second flange 12 and being higher than the second flange 12, the second flange 12 surrounding the outer periphery of the magnetic circuit system 3 and the voice coil 2, the first positioning shim 4 having an outer connecting edge 41 fixedly connected to the upper surface of the first flange 11, and the second positioning shim 5 having an outer connecting edge 41 fixedly connected to the upper surface of the second flange 12. In a plan view, the first flange 11 and the second flange 12 are ring-shaped and are arranged concentrically with the voice coil 2 and the magnetic circuit system 3, and the first positioning shim 4 and the second positioning shim 5 are ring-shaped as a whole and are arranged concentrically with the voice coil 2 and the magnetic circuit system 3. Specifically, the upper surface of the first flange 11 is fixedly connected to the lower surface of the outer connecting edge 41 of the first positioning shim 4, for example, by bonding with an adhesive, and the upper surface of the second flange 12 is fixedly connected to the lower surface of the outer connecting edge 41 of the second positioning shim 5, for example, by bonding with an adhesive. The outer connecting edges and inner connecting edges of the first positioning shim 4 and the second positioning shim 5 are each horizontally arranged. Here, the outer connecting edge 41 and the inner connecting edge 43 of the first positioning shim 4 are on the same horizontal plane, which is at the same height as or lower than the lowest point of the main body 42 of the first positioning shim 4 (specifically, the valley of the wave shape). The outer connecting edge 51 and the inner connecting edge 53 of the second positioning shim 5 are on the same horizontal plane, which is at the same height as or lower than the lowest point of the main body 52 of the first positioning shim 5 (specifically, the valley of the wave shape).

[0032] The magnetic circuit system 3 described above includes a magnetic conductive part 30, a magnetic steel 31 provided in the magnetic conductive part 30, and a front piece 32, a magnetic gap is formed between the inner surface of the magnetic conductive part 30 and the outer surfaces of the magnetic steel 31 and the front piece 32, the first positioning shim 4 has an inner connecting edge 43 connected to the upper surface of the magnetic conductive part 30, and the second positioning shim 5 has an inner connecting edge 43 connected to the lower surface of the magnetic conductive part 30. Furthermore, the magnetic conductive part 30 is bowl-shaped, and may be, for example, a U-shaped steel member. The magnetic-conductive component 30 includes a bottom 301 and a cylindrical side wall 302 extending downward from the edge of the bottom 301, the magnetic steel 31 and the front piece 32 being disposed within a space enclosed by the side wall 302, the first positioning shim 4 having an inner connecting edge 43 connected to the upper surface of the bottom 301 of the magnetic-conductive component 30, and the second positioning shim 5 having an inner connecting edge 43 connected to the lower surface of the side wall 302 of the magnetic-conductive component 30. Specifically, the lower surface of the inner connecting edge 43 of the first positioning shim 4 is fixedly connected to the upper surface of the bottom 301 of the magnetic-conductive component 30, and may be bonded thereto, for example, with an adhesive, and the upper surface of the inner connecting edge 43 of the second positioning shim 5 is fixedly connected to the lower surface of the side wall 302 of the magnetic-conductive component 30, and may be bonded thereto, for example, with an adhesive.

[0033] The base plate 10 further has a boss 13 extending upward in the center, and the lower end of the voice coil 2 is placed on the boss 13 and fixedly connected to the side surface of the boss 13, for example, by bonding with an adhesive. The bracket 1 may be provided with mounting holes so that it can be connected to a car seat with fasteners. A dust ring 71 is further provided on the base plate 10 of the bracket 1. Furthermore, a terminal board 6 is further embedded in the bracket 1, and the positive and negative leads of the voice coil 2 are connected to the terminal board 6, which is connected to an amplifier for passing electrical current to the audio signal.

[0034] Furthermore, the base plate 10 of the bracket 1 is further provided with an adhesive layer 72 for adhering to the car seat, for example for bonding to a sheet metal part of the car seat. The adhesive layer may be an adhesive tape, for example a double-sided tape.

[0035] The in-vehicle low-frequency vibrator of this embodiment uses two positioning shims, a first positioning shim 4 and a second positioning shim 5, to flexibly connect the magnetic circuit system 3 and the bracket 1. When the vibrator is operating, the vibrating magnetic circuit system 3 and the voice coil 2 simultaneously move along the axial direction (the center line direction of the voice coil 2). The two positioning shims improve structural stability, and the material, number of stitches, and hardness of the positioning shims can be adjusted to better control the performance parameters of the actuator. At the same time, the bracket 1 is used as an installation method, and can be combined with double-sided adhesive fixing or bolt fixing modes, making operation simple.

[0036] 4 and 5 show another example of an in-vehicle low-frequency vibrator. This example differs from the in-vehicle low-frequency vibrator shown in FIGS. 1 to 3 in that, as shown in FIGS. 4 and 5, a base plate 10 is provided with bolts 8 instead of an adhesive layer, and is tightly connected to the car seat via the bolts 8. Specifically, the bolts 8 are fixed to the base plate 10 or are integrally formed with the base plate 10, and the base plate 10 is fixed to a sheet metal part of the car seat by the bolts 8. The base plate 10 may be made of plastic, and the bolts 8 may be made of metal, and both may be molded by an insert injection molding process, or the bolts 8 may be made of plastic, and both may be integrally injection molded.

[0037] Furthermore, the base plate 10 may be provided with an adhesive layer that can be bonded to a sheet metal part of the car seat. The bolts 8 and the adhesive layer cooperate to secure the in-vehicle low-frequency vibrator to the sheet metal part of the car seat.

[0038] (Comparative Example) The in-vehicle low-frequency vibrator provided in the comparative example differs from the embodiment shown in Figures 1 to 3 in the number and material of the positioning shims, but the other features are the same. That is, the U-shaped steel member of the in-vehicle low-frequency vibrator of the comparative example is connected to the bracket via a single steel positioning shim, which replaces the first and second positioning shims in the embodiment.

[0039] See FIG. 6 for the impedance curves of the in-vehicle low-frequency vibrator shown in FIGS. 1 to 3 and the comparative in-vehicle low-frequency vibrator. Here, the lighter and thinner curve represents the impedance curve of the comparative in-vehicle low-frequency vibrator, while the heavier and coarser curve represents the impedance curve of the in-vehicle low-frequency vibrator shown in FIGS. 1 to 3. Comparing the two impedance curves, the resonant frequency of the comparative in-vehicle low-frequency vibrator is about 460 Hz, while the resonant frequency of the in-vehicle low-frequency vibrator shown in FIGS. 1 to 3 is below 60 Hz. Clearly, the in-vehicle low-frequency vibrator shown in FIGS. 1 to 3 has a lower low-frequency frequency, and the advantages are very obvious.

[0040] Those skilled in the art will understand that as used herein, the singular forms "a," "the," and "the" may include the plural forms as well, unless specifically stated otherwise.

[0041] As used in this specification and claims, the terms "comprise" and "include" are intended to indicate the inclusion of explicitly identified steps and elements only, and do not constitute an exclusive list; other steps or elements may also be included in the method or apparatus.

[0042] Additionally, it will be understood that "plurality" in this disclosure refers to two or more and other quantifiers similar thereto.

[0043] Furthermore, while terms such as "first" and "second" are used to describe various pieces of information, it is understood that these pieces of information should not be limited to these terms. These terms are merely used to distinguish between pieces of information of the same type and do not imply a particular order or importance. In fact, terms such as "first" and "second" can be used interchangeably. For example, first information can also be referred to as second information, and similarly, second information can also be referred to as first information, without departing from the scope of this disclosure.

[0044] In this embodiment, unless expressly stated and limited otherwise, a first feature being "above" or "below" a second feature may include direct contact between the first and second features, or may include contact between the first and second features via other features between them rather than direct contact. Furthermore, a first feature being "above," "above," and "on the upper surface" of a second feature may include the first feature being directly above or diagonally above the second feature, or may simply indicate that the horizontal height of the first feature is higher than that of the second feature. A first feature being "below," "below," and "on the lower surface" of a second feature may include the first feature being directly below or diagonally below the second feature, or may simply indicate that the horizontal height of the first feature is lower than that of the second feature.

[0045] The above examples are merely intended to illustrate the technical ideas and features of the present disclosure and are preferred examples, with the objective of allowing those familiar with the technology to understand and practice the contents of the present disclosure, but they do not limit the scope of protection of the present disclosure. [Explanation of symbols]

[0046] 1 bracket, 2 voice coil, 3 magnetic circuit system, 4 first positioning shim, 5 second positioning shim, 6 terminal board, 8 bolt, 10 base plate, 11 first flange, 12 second flange, 13 boss, 30 magnetically conductive part, 31 magnetic steel, 32 front piece, 41 outer connecting edge, 42 main body, 43 inner connecting edge, 51 outer connecting edge, 52 main body, 53 inner connecting edge, 71 dust ring, 72 adhesive layer, 301 bottom, 302 side wall

Claims

1. An in-vehicle low-frequency vibrator comprising: a bracket; a magnetic circuit system having a magnetic gap; and a voice coil having an upper end inserted into the magnetic gap and a lower end connected to the bracket, Further comprising a first positioning shim and a second positioning shim, each of which includes an outer connecting edge, an inner connecting edge, and a main body made of a woven fabric and connected between the outer connecting edge and the inner connecting edge; the magnetic circuit system is at least partially located within the bracket; the first positioning shim has an outer connecting edge connected to the top of the bracket and an inner connecting edge connected to an upper portion of the magnetic circuit system; The second positioning shim is located below the first positioning shim, and the outer connecting edge of the second positioning shim is connected to the lower part of the bracket, and the inner connecting edge of the second positioning shim is connected to the lower part of the magnetic circuit system.

2. 2. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the main body has flexibility.

3. 3. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the fabric is one or a combination of materials selected from the group consisting of cotton, linen, sieve cloth, COMEX, and blended fabrics.

4. 4. The in-vehicle low-frequency vibrator according to claim 1, wherein the main body of the first positioning shim has one or more wave shapes that rise and fall, and the circular or geometric center of the wave shape is located on the center line of the voice coil.

5. 5. The in-vehicle low-frequency vibrator according to claim 1, wherein the main body of the second positioning shim has one or more wave shapes that rise or fall, and the circular or geometric center of the wave shape is located on the center line of the voice coil.

6. 6. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the outer connecting edge and the inner connecting edge of the first positioning shim and / or the second positioning shim are each horizontally disposed.

7. the outer connecting edge and the inner connecting edge of the first positioning shim are on the same horizontal plane; 7. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the horizontal surface is at the same height as the lowest point of the main body or lower than the lowest point of the main body.

8. the outer connecting edge and the inner connecting edge of the second positioning shim are on the same horizontal plane; 8. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the horizontal surface is at the same height as the lowest point of the main body or lower than the lowest point of the main body.

9. 9. The in-vehicle low-frequency vibrator according to claim 1, wherein the bracket comprises a base plate for connecting to a car seat, a first flange and a second flange extending upward from the base plate, the first flange surrounding the outer periphery of the second flange and being higher than the second flange, the second flange surrounding the outer periphery of the magnetic circuit system and the voice coil, the first positioning shim having an outer connecting edge fixedly connected to an upper surface of the first flange, and the second positioning shim having an outer connecting edge fixedly connected to an upper surface of the second flange.

10. 10. The in-vehicle low-frequency vibrator according to claim 9, wherein the magnetic circuit system comprises a magnetic conductive part, a magnetic steel provided in the magnetic conductive part, and a front piece, the magnetic gap being formed between an inner surface of the magnetic conductive part and outer surfaces of the magnetic steel and the front piece, the first positioning shim having an inner connecting edge connected to an upper surface of the magnetic conductive part, and the second positioning shim having an inner connecting edge connected to a lower surface of the magnetic conductive part.

11. 11. The in-vehicle low-frequency vibrator according to claim 10, characterized in that the magnetic-conductive part has a bottom and a cylindrical side wall extending downward from the edge of the bottom, the magnetic steel and the front piece are arranged in a space surrounded by the side wall, the first positioning shim has an inner connecting edge connected to an upper surface of the bottom of the magnetic-conductive part, and the second positioning shim has an inner connecting edge connected to a lower surface of the side wall of the magnetic-conductive part.

12. 10. The in-vehicle low-frequency vibrator according to claim 9, further comprising a boss extending upward from the center of the base plate, the lower end of the voice coil being placed on the boss and fixedly connected to a side surface of the boss.

13. 13. The vehicle-mounted low-frequency vibrator according to claim 1, wherein the bracket is provided with bolts and / or an adhesive layer for connection to a car seat.

14. 14. The vehicle-mounted low-frequency vibrator according to claim 1, further comprising a terminal board provided inside the bracket and connected to a lead of the voice coil.

15. 15. A vehicle-mounted low-frequency vibrator according to any one of claims 1 to 14, wherein the vehicle-mounted low-frequency vibrator is arranged to be attached to a sheet metal part of a car seat.

16. A car audio system, A car audio system comprising the in-vehicle low-frequency vibrator according to any one of claims 1 to 15.

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