Semi-open earphone

Abstract

The technical scheme of the present application provides a semi-open earphone, which forms a sound passage in the earphone through the array-arranged grille through holes and the horn-shaped sound transmission holes provided on the front and rear shells. When sound is transmitted to the rear shell, the rear shell provided with the array-arranged horn-shaped sound transmission holes has low sound reflection and good sound transmission performance, which improves the overall sound quality while retaining the air flow resistance to a certain extent, effectively avoids the short circuit of low-frequency sound, and is beneficial to obtain excellent low-frequency performance.

Description

Technical Field

[0001] This invention belongs to the field of headphones, specifically relating to a semi-open headphone. Background Technology

[0002] Currently, headphones can be classified into three types based on their structure: closed-back, open-back, and semi-open-back. The difference between the three lies in the rear cavity structure, and different rear cavity structures have a significant impact on the resonance of sound in the rear cavity of the headphones.

[0003] Specifically, closed-back headphones use a closed acoustic chamber structure, confining the sound emitted by the headphones within the ear canal and the space between the ear and the user. Because the rear resonant chamber is closed, echoes and low-frequency buildup can occur, affecting sound clarity. Furthermore, while closed-back headphones effectively isolate external noise, the sound field is concentrated in the center of the head, which may cause ear pressure, discomfort during prolonged wear, and even hearing damage. Open-back headphones, on the other hand, use an open acoustic chamber structure. Because the rear resonant chamber is open, the sound emitted by the headphones can leak out. The advantage is that the sound field is no longer concentrated on the user's head, reducing ear pressure. However, this also results in a weaker low-frequency response, poorer isolation from external noise, and less bass performance. Larger speaker units are often needed to increase bass volume, but this increases distortion.

[0004] Since both closed-back and open-back headphones struggle to achieve a balanced sound across the mid, high, and low frequency ranges, there is an urgent need for a semi-open headphone that combines the advantages of both open-back and closed-back headphones, while being low-cost and portable. Summary of the Invention

[0005] To overcome the deficiencies described in the background section, the present invention provides a semi-open headphone, including a headphone shell, a suspension, a sound unit, and ear pads. The headphone shell includes a front shell disposed in the front cavity of the headphone and a rear shell disposed in the rear cavity of the headphone. The front and rear shells constitute an accommodating chamber for accommodating and installing the suspension and the sound unit. At least a portion of the front shell is provided with an array of grid-shaped through holes, and at least a portion of the rear shell is provided with an array of horn-shaped sound transmission holes.

[0006] Furthermore, the cross-section of the horn-shaped sound transmission hole in the rear housing is one or more combinations of circles, triangles, squares, rhombuses, and hexagons.

[0007] Furthermore, the cross-sectional area of ​​the horn-shaped sound transmission hole in the rear housing gradually increases or decreases from front to back.

[0008] Furthermore, the porosity of the rear shell is 0.01-0.3.

[0009] Furthermore, a front cavity reinforcement structure is provided between the front housing and the sound generating unit. At least a portion of the front cavity reinforcement structure is provided with an array of grid through holes, and the grid through hole area of ​​the front cavity reinforcement structure coincides with the grid through hole area of ​​the front housing in the axial direction.

[0010] Furthermore, the front housing and the front cavity reinforcement structure are provided with grid through holes distributed in a Fibonacci spiral pattern.

[0011] Furthermore, the grille through-holes of the front housing and / or front cavity reinforcement structure are horn-shaped through-holes.

[0012] Furthermore, the sound-generating unit includes a coil, a transducer diaphragm, and a magnet. The coil is fixedly mounted on the transducer diaphragm. The rear side of the front cavity reinforcement structure protrudes into a predetermined shape towards the transducer diaphragm. The shape of the front cavity reinforcement structure matches that of the transducer diaphragm, and a gap is formed between the two to create the required vibration space for the transducer diaphragm.

[0013] Furthermore, the suspension includes a main headphone suspension and a speaker unit suspension. The main headphone suspension connects the front housing and the speaker unit. The speaker unit suspension is used to fix the speaker unit and is fixedly connected to the main headphone suspension. The tuning hole in the main headphone suspension is used to connect the front cavity of the headphone and the rear cavity of the headphone. The tuning hole in the speaker unit suspension is used to connect the speaker unit and the rear cavity of the headphone.

[0014] Furthermore, the tuning holes in the main suspension of the headphones and the tuning holes in the suspension of the sound-producing unit are equipped with tuning cotton for adjusting acoustic damping, and the inner and outer sides of the rear shell are equipped with dustproof tuning cotton or dustproof sound-permeable cloth for adjusting acoustic damping.

[0015] This invention proposes a semi-open headphone. The headphone forms a sound channel within its casing through arrayed grille holes and horn-shaped sound-permeable holes on the front and rear shells. When sound reaches the rear shell, the arrayed horn-shaped sound-permeable holes result in low sound reflection and excellent sound transmission, improving overall sound quality while retaining some air resistance. This effectively prevents bass short-circuiting and contributes to superior bass performance. Furthermore, the suspension mounted inside the front and rear shells has tuning holes connecting the front and rear earpiece cavities, and the speaker unit and rear earpiece cavity, forming a sound channel. This allows for adjustment of sound propagation within the headphone and to the external environment by regulating air resistance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 This is an exploded structural diagram of the semi-open earphone of the present invention;

[0018] Figure 2 This is a schematic cross-sectional view of the semi-open earphone of the present invention;

[0019] Figure 3 This is an exploded structural diagram of the semi-open headphone front cavity of the present invention;

[0020] Figure 4 This is a schematic diagram of the split rear shell structure of the present invention;

[0021] Figure 5 This is one of the schematic diagrams of the overlapping perspective structure of the semi-open earphone front shell / rear shell and the corresponding rear shell structure of the present invention (triangular sound transmission hole).

[0022] Figure 6 This is the second schematic diagram of the overlapping perspective structure of the semi-open earphone front shell and rear shell of the present invention and the corresponding rear shell structure (circular sound transmission hole).

[0023] Figure 7 This is the third schematic diagram of the overlapping perspective structure of the semi-open earphone front shell and rear shell of the present invention, and the corresponding rear shell structure (square sound hole).

[0024] Figure 8 This is the third schematic diagram of the overlapping perspective structure of the semi-open earphone front shell and rear shell of the present invention, and the corresponding rear shell structure (hexagonal sound transmission hole).

[0025] Figure 9 Finite element cross-sectional diagrams representing the sound pressure level of various structural forms at 1kHz in finite element simulation experiments.

[0026] Figure 10 Frequency domain diagram of 20Hz-20kHz sweep frequency test for finite element simulation;

[0027] Figure 11 The frequency response curve of the finite element simulation experiment;

[0028] Figure 12 This is a graph showing the total harmonic distortion and noise test results of the semi-open headphone of this invention;

[0029] Figure 13 This is a graph showing the test results of the frequency response curves of the semi-open earphone of this invention compared with other earphones.

[0030] Figure 14 The second result graph shows the frequency response curve test results of the semi-open headphone of this invention compared with other headphones.

[0031] Key labels: 1-Earphone shell; 11-Front shell; 12-Rear shell; 121-Rear shell body; 122-Connector; 2-Suspension; 21-Earphone main suspension; 22-Sound unit suspension; 3-Sound unit; 31-Coil; 32-Transducer diaphragm; 33-Magnet; 4-Ear pad; 5-Tuning hole; 6-Tuning cotton; 7-Dustproof tuning cotton (dustproof tuning cloth); 8-Front cavity reinforcement structure. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the figures. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0034] The specific structural and functional details disclosed herein are merely representative and are intended to describe exemplary embodiments of the invention. However, the invention can be embodied in many alternative forms and should not be construed as being limited solely to the embodiments set forth herein.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0036] Currently, headphones can be classified into three types based on their structure: closed-back, open-back, and semi-open-back. The difference between the three lies in the rear cavity structure, and different rear cavity structures have a significant impact on the resonance of sound in the rear cavity of the headphones.

[0037] Specifically, closed-back headphones use a closed acoustic chamber structure, confining the sound emitted by the headphones within the ear canal and the space between the ear and the user. Because the rear resonant chamber is closed, echoes and low-frequency buildup can occur, affecting sound clarity. Furthermore, while closed-back headphones effectively isolate external noise, the sound field is concentrated in the center of the head, which may cause ear pressure, discomfort during prolonged wear, and even hearing damage. Open-back headphones, on the other hand, use an open acoustic chamber structure. Because the rear resonant chamber is open, the sound emitted by the headphones can leak out. The advantages are a more dispersed sound field and reduced ear pressure, but this also results in a weaker low-frequency response, poorer isolation from external noise, and less bass performance. Larger speaker units are often needed to increase bass volume, but this increases distortion.

[0038] It's important to note that the rear chamber design of headphones is one of the core design elements, determining the headphone's sound performance. Most high-end headphones currently on the market tend to use an open-back design to reduce sound resonance, avoid echoes and low-frequency buildup, thereby reducing total harmonic distortion and achieving higher sound quality. In contrast, semi-open headphones, due to the presence of the rear chamber, need to avoid numerous unnecessary acoustic short circuits to achieve good sound pickup. This allows the sound to be focused and dispersed in one direction, isolating external noise to some extent. Simultaneously, they need to generate subtle resonances at appropriate locations to compensate for transducer shortcomings, such as low-frequency tuning, while minimizing resonance and standing waves at other frequencies. This places high demands on the design of semi-open headphones, especially the rear chamber. While open-back headphones offer excellent sound quality in the mid-high frequencies, they suffer from low-frequency short circuits, resulting in poor low-frequency performance. Since both closed-back and open-back headphones struggle to achieve a balanced sound across the mid, high, and low frequency ranges, there is a pressing need for a low-cost, portable semi-open headphone that combines the advantages of both.

[0039] To address the aforementioned technical problems, the present invention provides a semi-open headphone that combines the high sound quality of open-back headphones in the mid-to-high frequency range with the low-frequency isolation provided by closed-back headphones, thereby achieving clearer mid-to-high frequencies and a richer bass. Specifically, the rear housing of the present invention has at least a portion of arrayed horn-shaped sound-permeable holes, which, together with the arrayed grille holes in at least a portion of the front housing, form a sound channel within the headphone. When sound is transmitted to the rear housing, due to the low sound reflection and good sound transmission performance of the rear housing, sound can pass through the rear housing with arrayed horn-shaped sound-permeable holes without loss. This improves the overall sound quality while retaining a certain degree of air resistance, effectively preventing bass short-circuiting and thus achieving excellent bass performance.

[0040] Definition of noun

[0041] Finite element simulation test: The model is a three-dimensional geometric model drawn by external CAD software. The three-dimensional geometric model is imported into the finite element simulation software through the interface between the finite element simulation software and the general CAD drawing software. The external point of the earphone, the center of the auricle, and the eardrum are selected as data acquisition points to obtain the sound pressure level (SPL) parameters of the corresponding data acquisition points in order to draw the SPL performance profile and frequency sweep line diagram of different earphones.

[0042] Frequency Response (FR): This reflects the efficiency of an electroacoustic device in converting electrical energy into sound vibrations. It is received by a microphone built into an artificial ear or head and torso simulator and presented in a graph in the form of dB / SPL. It is usually tested using a microphone with a frequency response range of 20-20KHz.

[0043] Head-Related Transfer Function (HRTF): This can be understood as a completely flat curve representing the sound transmitted from a speaker to the ear after being filtered by various parts of the body. In headphones, the relationship between HRTF and FR can be understood as follows: the closer the headphone's frequency response curve (FR) is to the HRTF, the more accurate and reproduced the sound. Target Response (RTR) is the headphone's frequency response curve under ideal conditions, or the international standard headphone curve.

[0044] Harman Target: In the low-frequency range, there is a 7-8 dB rise relative to the completely flat HRTF. Because the human ear structure has two bends, it will attenuate low-frequency sound waves. This value is about 7-8 dB, so the low-frequency part of FR needs to be raised accordingly.

[0045] The following is in conjunction with the appendix Figure 1-14 The technical solution of the present invention will be further described in detail with reference to specific embodiments.

[0046] Example 1:

[0047] This invention provides a semi-open headphone, such as... Figure 1-3As shown, the device includes an earphone housing 1, a suspension 2, a sound-generating unit 3, and ear pads 4. The earphone housing 1 includes a front housing 11 located in the front cavity of the earphone and a rear housing 12 located in the rear cavity of the earphone. The front and rear housings form a receiving chamber for accommodating and installing the suspension 2 and the sound-generating unit 3. The ear pads 4 are located on the user-facing side of the rear housing 12 to fix the contact surface between the earphone and the ear, while limiting sound leakage. The front housing 11 has an array of grid-shaped through holes in the middle, and the rear housing 12 has an array of horn-shaped sound-transmitting holes in the middle. Sound is transmitted to the ear through the array of grid-shaped through holes and horn-shaped sound-transmitting holes in the front and rear housings. An internal sound channel is formed. When sound is transmitted to the rear shell, the rear shell, which has an array of horn-shaped sound holes, reflects sound less and has good sound transmission performance. This improves the overall sound quality while retaining a certain degree of air resistance, effectively preventing short circuits in bass sound and contributing to excellent bass performance. The sound unit 3 is fixedly connected to the suspension 2. The suspension 2 has a tuning hole 5 for connecting the front cavity and rear cavity of the earphone, and the sound unit 3 and the rear cavity of the earphone, so as to form a sound channel. At the same time, the sound can be adjusted by adjusting the air resistance to adjust the propagation of sound inside the earphone and to the external environment, thereby achieving sound adjustment.

[0048] In this embodiment, the bottom of the rear housing is integrally formed with a threaded connection portion for connecting with the front housing. Other embodiments may optionally include, for example... Figure 4 As shown, the rear housing 12 further includes a rear housing body 121 and a separate connecting part 122 for connecting the front housing. The connecting part can fix the front and rear housings together as one unit by snap-fitting, fastening or screwing.

[0049] In this embodiment, the cross-section of the 12 horn-shaped sound-permeable holes in the rear housing is triangular. Figure 5 Due to the irregular shape of the triangular array, the frequency response curve of the headphones obtained from the COMSOL Multiphysics finite element simulation test is close to that of an ideal open-back headphone. Alternatively, in other embodiments, the 12 speaker-shaped sound holes on the rear shell are circular. Figure 6 ),square( Figure 7 ), rhombus, hexagon ( Figure 8 (or one or more of the following: octagonal)

[0050] In this embodiment, the cross-sectional area gradually increases from front to back. Alternatively, in other embodiments, the cross-sectional area of ​​the sound-permeable hole gradually converges from front to back. COMSOL Multiphysics finite element simulation experiments show that when the horn-shaped sound-permeable hole channels of the patented headphone shell array are reversed, they can still exhibit the same excellent sound structure as open-back headphones.

[0051] In this embodiment, the semi-open headphones are made of ABS plastic or polycarbonate plastic, materials that offer superior mechanical strength and durability, and are also relatively inexpensive, making them suitable for mass production. Furthermore, the headphone housing can be manufactured using injection molding technology, which helps reduce costs and improve production efficiency.

[0052] Verification has shown that the porosity of the rear shell is 0.05. A rear shell with a porosity of 0.05 can transmit sound with virtually no loss, and when the porosity reaches 0.1, the impact on sound is almost negligible. The porosity of the rear shell is selected between 0.01 and 0.3 to balance sound transmission and dustproof performance.

[0053] like Figure 1-3 As shown, to reduce resonance and standing waves, a front cavity reinforcement structure 8 is provided between the front housing 11 and the sound-generating unit 3. At least a portion of the front cavity reinforcement structure 8 has an array of grid through-holes. The grid through-hole area of ​​the front cavity reinforcement structure 8 coincides with the grid through-hole area of ​​the front housing 11 in the axial direction. The grid through-holes of the front housing 11 and / or the front cavity reinforcement structure 8 are horn-shaped through-holes. Specifically, in this embodiment, both the front housing 11 and the front cavity reinforcement structure 8 have arrayed grid through-holes in their middle sections. The grid through-holes are arranged in a Fibonacci spiral pattern, and the horn-shaped grid through-holes facilitate lossless sound transmission through the front housing and the front cavity reinforcement structure 8. Alternatively, in other embodiments, the grid through-holes may be offset from the middle of the front housing and the front cavity reinforcement structure, and one of the grid through-holes in the front housing and the front cavity reinforcement structure may be set as a horn-shaped through-hole, with the grid through-holes exhibiting other array patterns.

[0054] For illustration purposes, the following are five optional structures for semi-open headphones, which are only examples to illustrate the advantages of both open and closed headphones, as well as the low cost and portability of semi-open headphone structures.

[0055] Structure 1: The front housing 11 has an array of horn-shaped grille through holes in the middle, and the rear housing 12 has an array of horn-shaped sound holes in the middle. The porosity of the rear housing 12 is 0.05.

[0056] Structure 2: The front housing 11 has a horn-shaped grille through hole in the middle, which is arranged in a Fibonacci spiral pattern, and the rear housing 12 has an array of horn-shaped sound holes in the middle. The porosity of the rear housing 12 is 0.1.

[0057] Structure 3: The front housing 11 has a horn-shaped grille through hole in the middle, which is arranged in a Fibonacci spiral pattern. The rear housing 12 has an array of horn-shaped sound holes in the middle. The front cavity reinforcement structure 8 has a horn-shaped grille through hole in the middle, which is arranged in a Fibonacci spiral pattern. The porosity of the rear housing 12 is 0.05.

[0058] Structure 4: The front housing 11 has equal-aperture grid through holes arranged in a Fibonacci spiral pattern in the middle, the rear housing 12 has arrayed horn-shaped sound holes in the middle, the front cavity reinforcement structure 8 has horn-shaped grid through holes arranged in a Fibonacci spiral pattern in the middle, and the porosity of the rear housing 12 is 0.3.

[0059] Structure 5: The front housing 11 is eccentrically provided with an array of equal-diameter grid through holes, the rear housing 12 is eccentrically provided with an array of horn-shaped sound transmission holes, the front cavity reinforcement structure 8 is eccentrically provided with an array of horn-shaped grid through holes, the grid through hole area of ​​the front cavity reinforcement structure 8 coincides with the grid through hole area of ​​the front housing 11 in the axial direction, and the porosity of the rear housing 12 is 0.01.

[0060] Example 2:

[0061] Based on Embodiment 1, this embodiment provides a semi-open headphone. A tuning hole 5 is opened on the suspension 2, which is housed and installed inside the front and rear shells, to connect the front and rear cavity of the headphone, and the sound-generating unit 3 and the rear cavity of the headphone. This forms a sound channel and allows for adjustment of sound propagation within the headphone and to the external environment by regulating airflow resistance, thus achieving sound adjustment. Figure 1-3 As shown, the suspension 2 includes a main headphone suspension 21 and a speaker unit suspension 22. The main headphone suspension 21 and the speaker unit suspension 22 can be manufactured separately or integrally formed. The main headphone suspension 21 connects the front shell 11 and the speaker unit 3. The speaker unit suspension 22 is fixedly installed on the speaker unit 3 and is fixedly connected to the main headphone suspension 21. The tuning hole 5 opened in the main headphone suspension 21 is used to connect the front cavity of the headphone and the rear cavity of the headphone. The tuning hole 5 opened in the speaker unit suspension 22 is used to connect the speaker unit 3 and the rear cavity of the headphone. The tuning holes of the main headphone suspension and the speaker unit suspension can form a sound channel inside the headphone and can adjust the sound propagation inside the headphone and to the external environment by adjusting the air flow resistance. Specifically, the main suspension 21 of the earphone is provided with two arc-shaped tuning holes 5. The arc-shaped tuning holes are symmetrically arranged on opposite sides of the earphone suspension about the center of the suspension. The sound unit suspension 22 is fixedly installed in the inner circle of the main suspension 21 of the earphone and has several circular tuning holes evenly spaced. Tuning cotton is placed in the tuning holes of the main suspension of the earphone and the tuning holes of the sound unit suspension. After the mold is opened and put into production, the sound characteristics can be adjusted by adjusting the flow resistance of the tuning cotton.

[0062] like Figure 1-3 As shown, in this embodiment, a dustproof sound-adjusting cotton or a dustproof sound-permeable cloth 7 for sound damping adjustment is also provided between the shell and the main suspension 21 of the earphone or on the outside of the rear shell 12, in order to enhance the structure's ability to adjust the sound and to achieve dustproofing of the rear shell.

[0063] In this embodiment, the sound-generating unit 3 includes a coil 31, a transducer diaphragm 32, and a magnet 33. The coil 31 is fixedly mounted on the transducer diaphragm 32. The front cavity reinforcement structure 8 is flat on the front side and protrudes into a predetermined shape towards the transducer diaphragm 32 on the rear side. The shape of the front cavity reinforcement structure 8 matches that of the transducer diaphragm 32, and only a gap sufficient for the transducer diaphragm 32 to vibrate is maintained between them. This allows the transducer to effectively reduce segmented vibration and overall harmonic resonance distortion at different frequencies. Other embodiments may use a moving iron type, an electrostatic type, or a planar type sound-generating unit.

[0064] To further illustrate the sound performance of the semi-open headphones provided by the present invention, the inventors conducted the following experiments:

[0065] (1) Sound pressure level performance in finite element simulation test

[0066] The inventors used CAD and finite element simulation software to create a finite element model for analysis. Figure 9 This is a finite element cross-sectional diagram showing the sound pressure level (SPL) of various headphone structures at 1kHz. It should be noted that this simulation aims to illustrate the impact of different headphone rear cavity designs on sound penetration performance. The sound penetration performance of different headphones can be visually represented through their SPL morphology. Among all the headphones tested in the finite element simulation, the fully open-back headphone, with its open rear cavity, minimizes resonance and standing waves, allowing sound energy to be concentrated and dispersed in one direction. Therefore, the SPL morphology of the fully open-back headphone is the most ideal. The closer the headphone's SPL morphology is to that of the fully open-back headphone, the lower its sound reflection, the stronger its sound penetration, the higher its sound quality, and the lower its distortion.

[0067] In finite element simulation, such as Figure 9 As shown, the solutions of the entire frequency domain of the patented headphones with a porosity of 0.015 (with triangular horn-shaped sound holes arranged in the rear shell array, square horn-shaped sound holes arranged in the rear shell array, and diamond horn-shaped sound holes arranged in the rear shell array) are very close to those of fully open-back headphones. When the channels of the horn-shaped sound holes arranged in the outer shell array of the patented headphones are reversed, they can also exhibit the same excellent sound structure as open-back headphones. The sound pressure performance of traditional closed-back headphones with pressure relief holes, traditional semi-open rear cavity headphones with a single hole and a porosity of 0.015, and semi-open rear cavity headphones with perforated plates and a porosity of 0.015 are significantly different from those of fully open-back headphones.

[0068] Therefore, compared with traditional closed-back headphones and semi-open headphones with single holes or perforated plates, the sound penetration performance of this patented headphone with the array of horn-shaped sound holes on the rear shell is closer to that of fully open-back headphones, resulting in higher sound quality and less distortion.

[0069] (2) Frequency response curve of finite element simulation test

[0070] In finite element simulation, such as Figure 10 As shown, the frequency response curves of the patented headphones with a porosity of 0.015 (with triangular horn-shaped sound holes arranged in the rear shell, square horn-shaped sound holes arranged in the rear shell, and diamond horn-shaped sound holes arranged in the rear shell) are very close to those of fully open headphones in the 20Hz-20KHz range. The frequency response curves of traditional closed headphones with pressure relief holes, traditional semi-open rear cavity headphones with a single hole and a porosity of 0.015, and semi-open rear cavity headphones with perforated plates and a porosity of 0.015 differ significantly from those of fully open headphones.

[0071] Depend on Figure 11 It can be seen that a semi-open headphone with a porosity of 0.015 and a circular or rhomboid structure (the two structures are extremely similar in finite element analysis, and the obtained curves and results are the same) closely approximates the frequency response curve of an ideal fully open headphone, while the traditional single-hole semi-open rear cavity headphone or the perforated plate semi-open rear cavity headphone shows significant differences. This can be achieved through... Figure 11 The SPL values ​​corresponding to the two characteristic points of 1kHz and 3kHz in the frequency response curve are reflected. Specifically, the SPL response values ​​of the patented headphones at the above two points are close to those of an ideal open-structure rear cavity headphone (fully open headphone), with a frequency response difference of no more than 1dB. In contrast, the SPL value of a single-hole traditional semi-open rear cavity headphone differs from that of an ideal open-structure rear cavity headphone (fully open headphone) by more than 17dB at 1kHz. The SPL value of a perforated plate semi-open rear cavity headphone differs from that of an ideal open-structure rear cavity headphone (fully open headphone) by at least 3dB at 1kHz and by about 2dB at 3kHz. The response in the 1kHz-3kHz frequency domain is... The frequency response is more than 5dB lower than that of fully open headphones. It's generally believed that sound energy doubles every 3dB. Therefore, both single-hole traditional semi-open rear-cavity headphones and perforated plate semi-open rear-cavity headphones exhibit significant differences in frequency response curves and sound performance compared to fully open headphones. The frequency response curve and sound performance of the patented headphones are unmatched by traditional perforated plate structure headphones (the difference between traditional perforated plate structures and this patented headphone lies in whether the sound transmission holes in the rear shell are of equal width; traditional perforated plates have equal-diameter sound transmission holes, while this patented headphone has horn-shaped sound transmission holes) and single-hole traditional semi-open rear-cavity headphones, even with the same porosity, thickness, material, number of holes, and overlapping hole positions. Furthermore, the simulated frequency response curve of the patented headphones conforms to the international standard headphone curve based on standard human head simulation, namely the HRTF Target Response, with a gain of approximately 10dB between 1kHz and 3kHz. Other headphone structures cannot achieve this stringent standard.

[0072] from Figure 11The external point curves show that the patented headphones have an equally excellent external sound structure as ideal open-back headphones, which to some extent reflects that the total harmonic distortion and noise characteristics of the patented headphones are similar to those of ideal open-back headphones, and have the same or lower Total Harmonic Distortion + Noise (THD+n) as open-back headphones.

[0073] from Figure 11 The frequency response curve at the center of the auricle shows that the patented headphones have a curve that is close to that of open-back headphones but smoother, which indicates that the patented headphone design is more compatible with listeners with different ear canals.

[0074] From a low-frequency perspective, the patented headphones have superior low-frequency performance compared to open-back and perforated rear-cavity headphones.

[0075] (3) Total Harmonic Distortion and Noise Test

[0076] like Figure 12 As shown, the inventors, using different testing platforms, measured the total harmonic distortion (THD) of the patented headphone system to be less than 0.1%. The sum of the background noise, power amplifier transducer, and the harmonic distortion of the artificial ear device in the system is around 0.1%, and the harmonic distortion generated by the actual shell resonance is negligible (less than one ten-thousandth). This performance is far superior to most headphone products. Furthermore, the frequency response curve of the patented headphone precisely conforms to the Target Response of the international standard HRTF. Such excellent performance often requires headphones one to two times larger than the test headphones to achieve.

[0077] The actual test results show that they coincide with the finite element analysis data, which verifies the reliability of the finite element analysis simulation.

[0078] (4) Headphone frequency response curve test

[0079] 1. Test 1

[0080] Test subjects: This patented headphone, Sony WH1000XM4, Sennheiser HD800

[0081] like Figure 13 As shown, the original frequency response curve (line type 2) of the patented headphones, after balancing the HRTF curve (line type 5), shows a very flat frequency response curve (line type 1) under the same conditions, which is flatter than the frequency response curves of the other two headphones (line type 3 and line type 4).

[0082] 2. Test Two

[0083] Test subjects: Audio Technica ATH-EW9, AKG K712 Pro headphones, Beyerdynamic T1 3 rdGen headphones

[0084] Figure 14 The frequency response curves of the Audio Technica ATH-EW9, AKG K712 Pro, and Beyerdynamic T1 3rd Gen headphones after balanced HRTF curves are compared with those of the patented headphones under the same conditions. Figure 14 The three headphones in the series are more flat.

[0085] The foregoing has provided a detailed description of a semi-open headphone provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas and methods of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A semi-open headphone, comprising a headphone shell, a suspension, a sound-generating unit, and ear pads, characterized in that, The earphone housing includes a front housing with a front cavity and a rear housing with a rear cavity. The front and rear housings form a accommodating chamber for accommodating and mounting the suspension and the sound unit. At least a portion of the front housing has an array of grid-like through holes, and at least a portion of the rear housing has an array of horn-shaped sound-transmitting holes. The suspension includes a main earphone suspension and a sound unit suspension. The main earphone suspension connects the front housing and the sound unit. The sound unit suspension fixes the sound unit and is fixedly connected to the main earphone suspension. The tuning hole on the main earphone suspension connects the front cavity and the rear cavity of the earphone, and the tuning hole on the sound unit suspension connects the sound unit and the rear cavity of the earphone. The cross-sectional area of ​​the horn-shaped sound-transmitting holes on the rear housing gradually increases or decreases from front to back, and the porosity of the rear housing is 0.01-0.

3.

2. The semi-open earphone as described in claim 1, characterized in that, The cross-section of the horn-shaped sound-transmitting hole in the rear housing is one or more combinations of circles, triangles, squares, rhombuses, and hexagons.

3. The semi-open earphone as described in claim 1, characterized in that, A front cavity reinforcement structure is provided between the front housing and the sound generating unit. At least a portion of the front cavity reinforcement structure is provided with an array of grid through holes. The grid through hole area of ​​the front cavity reinforcement structure coincides with the grid through hole area of ​​the front housing in the axial direction.

4. The semi-open earphone as described in claim 3, characterized in that, The front housing and front cavity reinforcement structure are provided with grid through holes distributed in a Fibonacci spiral pattern in the middle.

5. The semi-open earphone as described in claim 4, characterized in that, The grille through-holes of the front housing and / or front cavity reinforcement structure are horn-shaped through-holes.

6. The semi-open earphone as described in claim 3, characterized in that, The sound-generating unit includes a coil, a transducer diaphragm, and a magnet. The coil is fixedly mounted on the transducer diaphragm. The front cavity reinforcement structure protrudes into the transducer diaphragm in a predetermined shape on its rear side. The shape of the front cavity reinforcement structure matches that of the transducer diaphragm, and a gap is formed between the two to create the vibration space required by the transducer diaphragm.

7. The semi-open earphone as described in claim 6, characterized in that, The tuning holes in the main suspension of the earphone and the tuning holes in the suspension of the sound-producing unit are equipped with tuning cotton for adjusting sound damping, and the inner and outer sides of the rear shell are equipped with dustproof tuning cotton or dustproof and sound-permeable cloth for adjusting sound damping.

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