A planar earphone with frequency response curve adjustment based on echo chamber structure and adjustment method

Abstract

The present invention relates to a flat-panel headset and an adjustment method for adjusting the frequency response curve based on an echo chamber structure. A flat-panel sound unit is designed to include a nano-diaphragm and an invisible magnet, thereby ensuring an extremely fast response speed of the flat-panel sound unit and reducing the diffraction effect caused by the invisible magnet. A wooden structure is used to form the external shell, making the sound line of the headset more balanced and natural, and improving the sound quality. A new device for adjusting the echo chamber structure is provided, so that the frequency response curve of the headset can be adjusted by adjusting the protruding height of the hollow plate and the distance between the hollow plates. The headset is physically structured to adjust the frequency response curve, so that adjusting the frequency response curve will not cause a loss of sound quality.

Description

Technical Field

[0001] The present invention relates to the field of planar headphones, and in particular to a planar headphone with an echo chamber structure for adjusting a frequency response curve and an adjustment method. Background Art

[0002] Planar headphones are known as planar-driven headphones. The "planar" part refers to the sound-producing unit. Thanks to their principle of sound generation, planar headphones naturally produce less distortion than dynamic headphones, resulting in better sound reproduction. Wooden headphones are popular with users for their more balanced and natural sound, improved sound quality, excellent sound reproduction, and elegant appearance.

[0003] Wooden headphones vary in density, elasticity, porosity, fiber shape, and adhesion. This results in significant differences in fundamental resonant frequency and material damping factor. Consequently, frequency response characteristics can vary slightly between different batches of wood, and even between different headphones from the same batch. This can lead to a lack of sonic uniformity in actual headphone production.

[0004] In order to ensure the uniformity of the headphone sound, the headphone needs to be tuned after production is completed. If software is used for tuning, it often leads to a decrease in sound reproduction or a decrease in sound quality. In order to avoid the decrease in sound quality caused by tuning, it is necessary to design a headphone that can adjust the frequency response curve physically so that the adjustment of the frequency response curve will not cause a loss of sound quality. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a planar earphone with a frequency response curve adjusted based on an echo chamber structure, comprising a headband and earphone shells provided at both ends of the headband.

[0006] The earphone shell includes an earmuff unit, a flat sound unit, a tuning unit and a wooden shell; the flat sound unit is fixedly arranged on the earmuff unit, and an earpiece cavity is formed between the earmuff unit and the wooden shell; an echo cavity structure is formed between the flat sound unit and the wooden shell;

[0007] The tuning unit is provided with a hollow plate, and the frequency response curve of the planar headphones can be adjusted by adjusting the position of the hollow plate.

[0008] The flat-panel sound unit includes a nano-diaphragm and an invisible magnet. The thickness of the nano-diaphragm is 500-1000nm. The extremely thin diaphragm thickness ensures the extremely fast response speed of the flat-panel sound unit. The invisible magnet is strip-shaped and arranged parallel to the surface where the nano-diaphragm is located, without contacting the nano-diaphragm. The invisible magnets are arranged in pairs on both sides of the nano-diaphragm. The edge of the invisible magnet perpendicular to its extension direction is parabolic on the side facing the nano-diaphragm, so that the sound emitted by the nano-diaphragm is affected by the invisible magnet and the diffraction effect is reduced.

[0009] The materials selected for the wooden shell are spruce, alder, rosewood, paulownia or pine.

[0010] There are two options for setting up the tuning unit, the first of which is:

[0011] The earmuff unit includes a sponge layer and a perforated plate layer. The sponge layer is annular, and a wire mesh cover is provided between the perforated plate layer and the sponge layer. A flat sound unit is installed on the other side of the perforated plate layer.

[0012] The wooden shell is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden shell and the perforated plate layer; a tuning unit is arranged between the flat sound unit and the wooden shell;

[0013] The tuning unit includes two hollow plates, namely a first hollow plate and a second hollow plate. The first hollow plate is arranged closer to the flat sound unit than the second hollow plate. The first hollow plate and the second hollow plate are both circular plates with equal diameters.

[0014] The first hollow plate is provided with parallel long strip through holes, and the second hollow plate is provided with parallel long strip through holes and long strip protrusions provided between the through holes, and the thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plate and the second hollow plate;

[0015] The through hole of the first hollow plate corresponds to the position of the protrusion of the second hollow plate, so that when the distance between the second hollow plate and the first hollow plate changes, the protrusion of the second hollow plate can be inserted into the through hole of the first hollow plate;

[0016] The through holes of the second hollow plate are arranged corresponding to the non-through hole area of ​​the first hollow plate, so that when the distance between the second hollow plate and the first hollow plate changes, the through holes of the second hollow plate can be blocked by the non-through hole area of ​​the first hollow plate.

[0017] The material of the first hollow plate and the second hollow plate is the same as that of the wooden housing.

[0018] An annular frame is provided at the edge of the second hollow plate, and the outside of the annular frame is connected to a driving device. The driving device drives the second hollow plate to move along the axis of the second hollow plate, thereby changing the distance between the second hollow plate and the first hollow plate; thereby adjusting the height of the protrusion of the second hollow plate protruding from the surface of the first hollow plate.

[0019] Second option:

[0020] The earmuff unit includes a sponge layer and a perforated plate layer. The sponge layer is annular, and a wire mesh cover is provided between the perforated plate layer and the sponge layer. A flat sound unit is installed on the other side of the perforated plate layer.

[0021] The wooden shell is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden shell and the perforated plate layer; a tuning unit is arranged between the flat sound unit and the wooden shell;

[0022] The tuning unit includes two groups of hollow plates, namely a second hollow plate group and a second hollow plate group. The second hollow plate group is arranged closer to the flat sounding unit than the second hollow plate group. The second hollow plate group and the second hollow plate group are both circular plates with equal diameters.

[0023] The second hollow plate group includes a plurality of independent first hollow plates, and the plurality of independent first hollow plates can be combined into a complete disc shape; each independent first hollow plate is provided with parallel long strip through holes, and the second hollow plate group includes a plurality of independent second hollow plates, and the plurality of independent second hollow plates can be combined into a complete disc shape; each independent second hollow plate is provided with parallel long strip through holes and long strip protrusions provided between the through holes, the thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plate and the second hollow plate, the number of the first hollow plates and the second hollow plates is the same, and the spacing, number, and height of the long strip protrusions on each independent second hollow plate are different;

[0024] The through hole of the first hollow plate corresponds to the position of the protrusion of the second hollow plate, so that when the distance between the second hollow plate and the first hollow plate changes, the protrusion of the second hollow plate can be inserted into the through hole of the first hollow plate;

[0025] The through holes of the second hollow plate are arranged corresponding to the non-through hole area of ​​the first hollow plate, so that when the distance between the second hollow plate and the first hollow plate changes, the through holes of the second hollow plate can be blocked by the non-through hole area of ​​the first hollow plate.

[0026] An outer frame is provided at the edge of each second hollow plate, and the outside of the outer frame is connected to a driving device. The driving device drives the second hollow plate to move along the axis of the second hollow plate, thereby changing the distance between the second hollow plate and the first hollow plate; thereby independently adjusting the height of the protrusion of each second hollow plate protruding from the surface of the first hollow plate.

[0027] A method for adjusting a frequency response curve based on an echo chamber structure, using the planar headphones, includes the following steps:

[0028] Step 1: Use finite element software to model the earphone shell and create a 3D model of the earphone shell. The earphone shell model is required to include the earmuff unit, flat sound unit, tuning unit, and wooden shell.

[0029] At the same time, a human ear model is established. According to the shape of the human ear, a 3D model of the human ear is constructed; the human ear model includes at least the auricle, ear canal and eardrum;

[0030] Step 2: A vibration source is set at the location of the flat-panel sound unit, emitting white noise vibrations, and the simulated environment is set to air. A human ear model is placed outside the earmuff unit, and a vibration detector is set at the eardrum of the human ear model to collect the vibration spectrum of the vibration emitted by the flat-panel sound unit and then reaching the eardrum after emitting from the earphone housing.

[0031] Step 3: For the case where there is only one first hollow plate and one second hollow plate: first, place the first hollow plate and the second hollow plate at the initial position, at which point the first hollow plate and the second hollow plate are closest to each other, and detect the vibration spectrum at the eardrum;

[0032] The second hollow plate is then moved m times, with each movement moving the second hollow plate further away from the first hollow plate. The change in the vibration spectrum at the eardrum relative to its initial position is measured with each movement. A position-spectrum correlation matrix is ​​obtained, which stores the corresponding changes in the second hollow plate and the vibration spectrum.

[0033] For the case where there are multiple first hollow plates and multiple second hollow plates: first, place the first hollow plate and the second hollow plate at the initial position, at which point the first hollow plate and the second hollow plate are closest to each other, and detect the vibration spectrum at the eardrum once;

[0034] Then, each second hollow plate is moved m positions. Assuming there are n second hollow plates, the permutation and combination requires mn moves in total. The change in the vibration spectrum at the eardrum relative to its initial position is measured after each movement. A position-spectrum correlation matrix is ​​obtained, which stores the corresponding changes in the second hollow plates and the vibration spectrum.

[0035] Step 4: Make the earphone shell. After the production is completed, test the earphone shell using an acoustic spectrum analyzer to obtain the actual frequency response curve of the earphone shell. Adjust the position of the second hollow plate according to the position-spectrum correlation matrix so that the frequency response curve is adjusted to be closest to the target curve.

[0036] The target curve is a Harman target curve, the number m is greater than or equal to 20, and n is 2 to 8.

[0037] The beneficial effects of the present invention are:

[0038] First, the invention features a flat-panel sound unit comprised of a nanodiaphragm and invisible magnets. The extremely thin diaphragm ensures a fast response, while the unique shape of the invisible magnets reduces diffraction effects on the sound emitted by the nanodiaphragm. Using tonewood (musical wood) to form the exterior shell, the enclosed interior creates an echo chamber, suppressing both the frequency spectrum and vibrations. This results in a more balanced and natural sound line and enhanced sound quality.

[0039] In another aspect, the present invention provides a novel device for adjusting the echo chamber structure, enabling the frequency response curve of headphones to be adjusted by adjusting the protruding height and spacing of the hollow plates. This achieves a physically adjustable frequency response curve without sacrificing sound quality. Furthermore, it provides a solution for using multiple secondary hollow plates, each with different protruding spacing, height, and number, thereby increasing the range and accuracy of frequency response adjustment. Furthermore, a method for adjusting the headphones is provided, which is simple in design, requires no machining, and provides accurate simulation results with high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Attachment Figure 1 This is an appearance diagram of the flat-panel earphones of the present invention;

[0042] Attachment Figure 2 This is a disassembled diagram of the earphone housing of the flat earphone of the present invention;

[0043] Attachment Figure 3 The front, side, and combined views of the first and second hollow plates of the tuning unit of Example 1 of the present invention are shown;

[0044] Attachment Figure 4 The front, side and combination diagrams of the first hollow plate and the second hollow plate of the tuning unit of the second embodiment of the invention (when there are two of each hollow plate). DETAILED DESCRIPTION

[0045] Example 1:

[0046] See also Figure 1-3 The present invention provides a planar earphone with a frequency response curve adjusted based on an echo chamber structure, comprising a headband 1 and earphone shells 2 provided at both ends of the headband 1.

[0047] The earphone housing 2 includes an earmuff unit 3, a flat sound unit 4, a tuning unit 5, and a wooden shell 6. The flat sound unit 4 is fixedly mounted on the earmuff unit 3, and an earpiece cavity is formed between the earmuff unit 3 and the wooden shell 6. An echo cavity structure is formed between the flat sound unit 4 and the wooden shell.

[0048] The tuning unit 5 is provided with a hollow plate 51 , and the frequency response curve of the planar earphone can be adjusted by adjusting the position of the hollow plate.

[0049] The flat-panel sound unit 4 includes a nano-diaphragm 41 and an invisible magnet 42. The thickness of the nano-diaphragm 41 is 500-1000nm. The extremely thin diaphragm thickness ensures the extremely fast response speed of the flat-panel sound unit 4. The invisible magnet 42 is strip-shaped and arranged parallel to the surface where the nano-diaphragm 41 is located, without contacting the nano-diaphragm 41. The invisible magnets 42 are arranged in pairs on both sides of the nano-diaphragm 41. The edge of the invisible magnet 42 perpendicular to its extension direction and facing the nano-diaphragm 41 is parabolic, so that the sound emitted by the nano-diaphragm 41 is affected by the invisible magnet 42 and the diffraction effect is reduced.

[0050] The material selected for the wooden shell 6 is spruce, alder, rosewood, paulownia or pine.

[0051] There are two solutions for setting up the tuning unit. The solution in this embodiment is:

[0052] Combine Figure 3 The earmuff unit 3 includes a sponge layer and a perforated plate layer. The sponge layer is annular, and a wire mesh cover is provided between the perforated plate layer and the sponge layer; a flat sound unit 4 is installed on the other side of the perforated plate layer;

[0053] The wooden shell 6 is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden shell 6 and the perforated plate layer; a tuning unit 5 is provided between the flat sound unit 4 and the wooden shell 6;

[0054] The tuning unit 5 includes two hollow plates, namely a first hollow plate 52 and a second hollow plate 53. The first hollow plate 52 is arranged closer to the flat sound unit 4 than the second hollow plate 53. The first hollow plate 52 and the second hollow plate 53 are both circular plates with equal diameters.

[0055] The first hollow plate 52 is provided with parallel long strip through holes, and the second hollow plate 53 is provided with parallel long strip through holes and long strip protrusions provided between the through holes. The thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plate 52 and the second hollow plate 53.

[0056] The through holes of the first hollow plate 52 correspond to the positions of the protrusions of the second hollow plate 53, so that when the distance between the second hollow plate 53 and the first hollow plate 52 changes, the protrusions of the second hollow plate 53 can be inserted into the through holes of the first hollow plate 52;

[0057] The through holes of the second hollow plate 53 are arranged corresponding to the non-through hole area of ​​the first hollow plate 52, so that when the distance between the second hollow plate 53 and the first hollow plate 52 changes, the through holes of the second hollow plate 53 can be blocked by the non-through hole area of ​​the first hollow plate 52.

[0058] The material of the first hollow plate 52 and the second hollow plate 53 is the same as that of the wooden housing.

[0059] An annular frame is provided at the edge of the second hollow plate 53, and the outside of the annular frame is connected to a driving device. The driving device drives the second hollow plate 53 to move along the axis of the second hollow plate 53, so that the distance between the second hollow plate 53 and the first hollow plate 52 changes; thereby adjusting the height of the protrusion of the second hollow plate 53 protruding from the surface of the first hollow plate 52.

[0060] Example 2:

[0061] Combine Figure 2 and 4 The earmuff unit 3 includes a sponge layer and a perforated plate layer. The sponge layer is annular, and a wire mesh cover is provided between the perforated plate layer and the sponge layer; a flat sound unit 4 is installed on the other side of the perforated plate layer;

[0062] The wooden shell 6 is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden shell 6 and the perforated plate layer; a tuning unit 5 is provided between the flat sound unit 4 and the wooden shell 6;

[0063] The tuning unit 5 includes two groups of hollow plates, namely a second hollow plate group and a second hollow plate group. The second hollow plate group is arranged closer to the flat sound unit 4 than the second hollow plate group. The second hollow plate group and the second hollow plate group are both circular plates with equal diameters.

[0064] The second hollow plate group includes a plurality of independent first hollow plates, and the plurality of independent first hollow plates 52 can be combined into a complete disc shape; each independent first hollow plate 52 is provided with parallel long strip through holes, and the second hollow plate group includes a plurality of independent second hollow plates, and the plurality of independent second hollow plates 53 can be combined into a complete disc shape; each independent second hollow plate 53 is provided with parallel long strip through holes and long strip protrusions provided between the through holes, and the thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plates 52 and the second hollow plates 53. The number of the first hollow plates 52 and the second hollow plates 53 is the same, and the spacing, number, and height of the long strip protrusions on each independent second hollow plate 53 are different;

[0065] The through holes of the first hollow plate 52 correspond to the positions of the protrusions of the second hollow plate 53, so that when the distance between the second hollow plate 53 and the first hollow plate 52 changes, the protrusions of the second hollow plate 53 can be inserted into the through holes of the first hollow plate 52;

[0066] The through holes of the second hollow plate 53 are arranged corresponding to the non-through hole area of ​​the first hollow plate 52, so that when the distance between the second hollow plate 53 and the first hollow plate 52 changes, the through holes of the second hollow plate 53 can be blocked by the non-through hole area of ​​the first hollow plate 52.

[0067] An outer frame is provided at the edge of each second hollow plate 53, and the outside of the outer frame is connected to a driving device. The driving device drives the second hollow plate 53 to move along the axis of the second hollow plate 53, thereby changing the distance between the second hollow plate 53 and the first hollow plate 52; thereby independently adjusting the height of the protrusion of each second hollow plate 53 protruding from the surface of the first hollow plate 52.

[0068] Example 3:

[0069] A method for adjusting a frequency response curve based on an echo chamber structure, using the planar headphones, includes the following steps:

[0070] Step 1: Use finite element software to model the earphone housing 2 and create a 3D model of the earphone housing 2; the earphone housing 2 model is required to include an earmuff unit 3, a flat sound unit 4, a tuning unit 5, and a wooden shell 6;

[0071] At the same time, a human ear model is established. According to the shape of the human ear, a 3D model of the human ear is constructed; the human ear model includes at least the auricle, ear canal and eardrum;

[0072] Step 2: A vibration source is set at the position of the flat-panel sound unit 4, emitting white noise vibrations, and the simulated environment is set to an air environment; a human ear model is placed outside the earmuff unit 3, and a vibration detector is set at the eardrum of the human ear model to collect the vibration spectrum of the vibration emitted by the flat-panel sound unit 4 and then reaching the eardrum after being emitted from the earphone housing 2;

[0073] Step 3: For the case where there is only one first hollow plate 52 and one second hollow plate 53: first, place the first hollow plate 52 and the second hollow plate 53 at the initial position. At this time, the first hollow plate 52 and the second hollow plate 53 are closest to each other, and detect the vibration spectrum at the eardrum once;

[0074] Then, the second hollow plate 53 is moved m times, with each movement moving the second hollow plate 53 further away from the first hollow plate 52. The change in the vibration spectrum at the eardrum relative to the initial position is measured each time the second hollow plate 53 is moved. A position-spectrum correlation matrix is ​​obtained, which stores the corresponding changes in the second hollow plate 53 and the vibration spectrum.

[0075] For the case where there are multiple first hollow plates 52 and multiple second hollow plates 53: first, place the first hollow plates 52 and the second hollow plates 53 at the initial position. At this time, the first hollow plates 52 and the second hollow plates 53 are closest to each other, and detect the vibration spectrum at the eardrum once;

[0076] Each second hollow plate 53 is then moved m positions. Assuming there are n second hollow plates 53, the permutation and combination requires a total of mn moves. The change in the vibration spectrum at the eardrum relative to its initial position is measured for each move. A position-spectrum correlation matrix is ​​obtained, which stores the corresponding changes in the second hollow plates 53 and the vibration spectrum.

[0077] Step 4: Make the earphone shell 2. After the production is completed, test the earphone shell 2 using an acoustic spectrometer to obtain the actual frequency response curve of the earphone shell 2. Adjust the position of the second hollow plate 53 according to the position-spectrum correlation matrix so that the frequency response curve is adjusted to be closest to the target curve.

[0078] The target curve is a Harman target curve, the number m is greater than or equal to 20, and n is 2 to 8.

[0079] A storage chip is also provided in the earphone shell to store the position-spectrum correlation matrix. If the user needs to tune the sound during use, he can use the earphone's matching tuning software to adjust it on a mobile phone or computer terminal; when adjusting, the earphone is wirelessly connected to the computer or mobile phone, and after the connection, the adjustment command is issued from the mobile phone or computer; the driving device in the earphone adjusts the frequency response curve of the earphone to the target curve set by the user according to the position-spectrum correlation matrix.

[0080] Thus far, the description of the above-described embodiments has been provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to the particular embodiment, but when applicable, they can be interchanged and used for selected embodiments even if not specifically shown or described. In many aspects, the same elements or features can also be changed. Such changes are not considered to depart from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

[0081] Example embodiments are provided so that the present disclosure will be thorough and will fully convey the scope to those skilled in the art. In order to thoroughly understand the embodiments of the present disclosure, numerous details are set forth, such as examples of specific parts, devices, and methods. It will be apparent to those skilled in the art that specific details need not be used, and the example embodiments may be implemented in many different forms, and neither should be construed as limiting the scope of the present disclosure. In certain example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0082] Here, professional vocabulary is used only for the purpose of describing specific example embodiments and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a" and "the" used herein may be intended to include the plural forms as well. The terms "including" and "having" are inclusive and therefore specify the presence of the claimed features, wholes, steps, operations, elements and / or components, but do not exclude the presence or additional presence of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof. Unless the order of execution is explicitly indicated, the method steps, processes and operations described herein are not to be interpreted as necessarily needing to be performed in the specific order discussed and shown. It should also be understood that additional or optional steps may be adopted.

Claims

1. A method for adjusting a frequency response curve based on an echo chamber structure, using a planar headphone for adjusting a frequency response curve based on an echo chamber structure, the planar headphone comprising a headband (1) and headphone shells (2) provided at both ends of the headband (1), characterized in that: The earphone housing (2) comprises an earmuff unit (3), a flat sound-generating unit (4), a tuning unit (5) and a wooden shell (6); the flat sound-generating unit (4) is fixedly arranged on the earmuff unit (3), and an earpiece cavity is formed between the earmuff unit (3) and the wooden shell (6); an echo cavity structure is formed between the flat sound-generating unit (4) and the wooden shell; The tuning unit (5) is provided with a hollow plate (51), and the frequency response curve of the flat headphone is adjusted by adjusting the position of the hollow plate; The adjustment method includes the following steps: Step 1: Model the earphone housing (2) using finite element software to establish a 3D model of the earphone housing (2); the earphone housing (2) model is required to include an earmuff unit (3), a flat sound unit (4), a tuning unit (5) and a wooden shell (6); At the same time, a human ear model is established. According to the shape of the human ear, a 3D model of the human ear is constructed; the human ear model includes at least the auricle, ear canal and eardrum; Step 2: a vibration source is set at the position of the flat sound unit (4), the vibration source emits white noise vibration, and the simulated environment is set to an air environment; a human ear model is placed outside the earmuff unit (3), and a vibration detector is set at the eardrum of the human ear model to collect the vibration spectrum of the vibration emitted from the flat sound unit (4) and then emitted from the earphone housing (2) to the eardrum; Step 3: For the case where there is only one first hollow plate (52) and one second hollow plate (53): first, place the first hollow plate (52) and the second hollow plate (53) at an initial position, where the first hollow plate (52) and the second hollow plate (53) are closest to each other, and detect the vibration spectrum at the eardrum once; Then, the second hollow plate (53) is moved m times, and each time the second hollow plate (53) is moved, the second hollow plate (53) is further away from the first hollow plate (52); each time the movement is performed, the change of the vibration spectrum at the eardrum relative to the initial position is measured; and a position-spectrum correlation matrix is ​​obtained, in which the change of the second hollow plate (53) and the vibration spectrum is correspondingly stored; For the case where there are multiple first hollow plates (52) and multiple second hollow plates (53): first, the first hollow plate (52) and the second hollow plate (53) are placed at an initial position, at which point the first hollow plate (52) and the second hollow plate (53) are closest to each other, and a vibration spectrum at the eardrum is detected once; Then, each second hollow plate (53) is moved m positions. If there are n second hollow plates (53) in total, the permutation combination moves m positions in total. n times; measuring the change of the vibration spectrum at the eardrum relative to the initial position each time the movement is performed; obtaining a position-spectrum correlation matrix, in which the change of the second hollow plate (53) and the vibration spectrum is correspondingly stored; Step 4: Make an earphone shell (2). After the production is completed, the earphone shell (2) is tested using an acoustic spectrum analyzer to obtain the frequency response curve of the actual earphone shell (2). The position of the second hollow plate (53) is adjusted according to the position-spectrum correlation matrix so that the frequency response curve is adjusted to be closest to the target curve.

2. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 1, characterized in that: The flat-panel sound-emitting unit (4) includes a nano-diaphragm (41) and an invisible magnet (42), wherein the thickness of the nano-diaphragm (41) is 500-1000 nm. The extremely thin thickness of the diaphragm ensures an extremely fast response speed of the flat-panel sound-emitting unit (4); the invisible magnet (42) is in a strip shape and is arranged parallel to the surface where the nano-diaphragm (41) is located, without contacting the nano-diaphragm (41), and the invisible magnets (42) are arranged in pairs on both sides of the nano-diaphragm (41). The edge of the invisible magnet (42) perpendicular to the cross section of the invisible magnet (42) in the extension direction toward the side of the nano-diaphragm (41) is parabolic, so that the sound emitted by the nano-diaphragm (41) is affected by the invisible magnet (42) and the diffraction effect is reduced.

3. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 1, characterized in that: The material selected for the wooden housing (6) is spruce, alder, rosewood, paulownia or pine.

4. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 1, characterized in that: The earmuff unit (3) comprises a sponge layer and a perforated plate layer, the sponge layer being annular, and a wire mesh cover being provided between the perforated plate layer and the sponge layer; a flat sound generating unit (4) is installed on the other side of the perforated plate layer; The wooden housing (6) is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden housing (6) and the perforated plate layer; a tuning unit (5) is provided between the flat sound generating unit (4) and the wooden housing (6); The tuning unit (5) includes two hollow plates, namely a first hollow plate (52) and a second hollow plate (53), wherein the first hollow plate (52) is arranged closer to the flat sound-generating unit (4) than the second hollow plate (53); the first hollow plate (52) and the second hollow plate (53) are both circular plates with the same diameter; The first hollow plate (52) is provided with parallel long strip through holes, and the second hollow plate (53) is provided with parallel long strip through holes and long strip protrusions provided between the through holes, and the thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plate (52) and the second hollow plate (53); The through hole of the first hollow plate (52) corresponds to the position of the protrusion of the second hollow plate (53), so that when the distance between the second hollow plate (53) and the first hollow plate (52) changes, the protrusion of the second hollow plate (53) can be inserted into the through hole of the first hollow plate (52); The through holes of the second hollow plate (53) are arranged corresponding to the non-through hole area of ​​the first hollow plate (52), so that when the distance between the second hollow plate (53) and the first hollow plate (52) changes, the through holes of the second hollow plate (53) can be blocked by the non-through hole area of ​​the first hollow plate (52).

5. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 4, characterized in that: The material of the first hollow plate (52) and the second hollow plate (53) is the same as that of the wooden shell.

6. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 4, characterized in that: An annular frame is provided at the edge of the second hollow plate (53), and the outside of the annular frame is connected to a driving device, which drives the second hollow plate (53) to move along the axis of the second hollow plate (53), thereby changing the distance between the second hollow plate (53) and the first hollow plate (52); thereby adjusting the height of the protrusion of the second hollow plate (53) protruding from the surface of the first hollow plate (52).

7. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 1, characterized in that: The earmuff unit (3) comprises a sponge layer and a perforated plate layer, the sponge layer being annular, and a wire mesh cover being provided between the perforated plate layer and the sponge layer; a flat sound generating unit (4) is installed on the other side of the perforated plate layer; The wooden housing (6) is fixedly connected to the perforated plate layer, thereby forming an earpiece cavity between the wooden housing (6) and the perforated plate layer; a tuning unit (5) is provided between the flat sound generating unit (4) and the wooden housing (6); The tuning unit (5) includes two groups of hollow plates, namely a first hollow plate group and a second hollow plate group, wherein the first hollow plate group is arranged closer to the flat sound generating unit (4) than the second hollow plate group; the first hollow plate group and the second hollow plate group are both circular plates with equal diameters; The first hollow plate group includes a plurality of independent first hollow plates, and the plurality of independent first hollow plates (52) can be combined into a complete disc shape; each independent first hollow plate (52) is provided with parallel long strip through holes, and the second hollow plate group includes a plurality of independent second hollow plates, and the plurality of independent second hollow plates (53) can be combined into a complete disc shape; each independent second hollow plate (53) is provided with parallel long strip through holes and long strip protrusions provided between the through holes, the thickness of the long strip protrusions is greater than the sum of the thicknesses of the first hollow plate (52) and the second hollow plate (53), the number of the first hollow plates (52) and the second hollow plates (53) is the same, and the spacing, number, and height of the long strip protrusions on each independent second hollow plate (53) are different; The through hole of the first hollow plate (52) corresponds to the position of the protrusion of the second hollow plate (53), so that when the distance between the second hollow plate (53) and the first hollow plate (52) changes, the protrusion of the second hollow plate (53) can be inserted into the through hole of the first hollow plate (52); The through holes of the second hollow plate (53) are arranged corresponding to the non-through hole area of ​​the first hollow plate (52), so that when the distance between the second hollow plate (53) and the first hollow plate (52) changes, the through holes of the second hollow plate (53) can be blocked by the non-through hole area of ​​the first hollow plate (52).

8. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 7, characterized in that: An outer frame is provided at the edge of each second hollow plate (53), and the outer frame is externally connected to a driving device, and the driving device drives the second hollow plate (53) to move along the axis of the second hollow plate (53) group, thereby changing the distance between the second hollow plate (53) and the first hollow plate (52); thereby independently adjusting the height of the protrusion of each second hollow plate (53) protruding from the surface of the first hollow plate (52).

9. The method for adjusting the frequency response curve based on the echo chamber structure according to claim 1, characterized in that: The target curve is a Harman target curve, the number m is greater than or equal to 20, and n is 2 to 8.

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