Dual sound source wave front non-common cavity horizontal coupling tweeter waveguide

Abstract

The application provides a double-sound-source wave front non-common cavity horizontal coupling high-pitched wave guide, the wave guide is Y-shaped, comprising two wave guide channels arranged horizontally, the wave guide channels are used for connecting spherical wave high-pitched drivers, and the wave guide channels are composed of a first channel, a first reflecting surface, a second channel, a second reflecting surface and a third channel connected in sequence. The wave guide of the application makes two or more compression drivers (high-pitched or medium-pitched drivers) sound sources coupled in a horizontal position without sharing a cavity in a wave front, and converts the sound waves into a wave front in a plane wave shape and without acoustic interference. The wave guide of the application can increase the maximum sound pressure level by ≥6dB relative to the wave guide of the prior art which is coupled vertically with a single driver.

Description

Technical Field

[0001] This invention relates to an acoustic waveguide, and more particularly to a waveguide for horizontal and vertical coupling radiation of multiple identical or different driver sound sources in a loudspeaker with non-co-cavity wavefronts. Background Technology

[0002] As the requirements for loudspeaker reproduction quality in the sound reinforcement field increase, and the sound pressure level covering both near and far fields needs to be consistent and uniform, line sound sources, which offer better sound reinforcement performance than traditional point sound sources, are gradually being promoted. Line array speaker systems, which diffuse sound using line sources, are characterized by a small vertical angle for each loudspeaker, effectively solving the problem of sound interference between loudspeakers. At the same time, line array speaker systems exhibit slow sound pressure attenuation and long transmission distance.

[0003] like Figure 1 As shown, point source 2 refers to sound that diffuses as a spherical wave from a point source. Its characteristics include a large coverage angle in both the horizontal and vertical directions, and rapid sound pressure attenuation. For spherical waves, the sound intensity at any distance from the source is inversely proportional to the square of the distance. For example... Figure 1 As shown, when the distance from the sound source increases from R to R2, which is twice R, the area of ​​the wavefront increases from A to 4A, and the sound intensity decreases to 1 / 4. Doubling the distance R results in a 6dB decrease in sound pressure level.

[0004] like Figure 2 As shown, line source 4 consists of a system of multiple cylindrical wave source speakers. Its tweeter driver is typically a ribbon driver that approximates a plane wave, such as the loudspeaker disclosed in US2007 / 0160233A1. Alternatively, a waveguide device can be used to convert a traditional compression driver into a cylindrical wave source similar to a plane wave, such as the acoustic waveguide disclosed in US5163167A. The vertical high-frequency directivity of the line source loudspeaker is very narrow, typically around 5-10 degrees. The energy of the cylindrical wave attenuates by 3dB whenever the distance to the source doubles. The wavefront generated by line source 4 is a coaxial cylindrical wave, called a cylindrical wave. A cylindrical wave is a wave with a coaxial cylindrical wavefront. Imagine an infinitely long, uniform line source in an infinitely uniform medium; the wave it produces would be an ideal cylindrical sound wave. In a cylindrical sound wave, the sound pressure amplitude is uniformly distributed along the axial direction and inversely proportional to the square root of the distance from the axis along the radial direction. Its radial sound intensity is inversely proportional to the first power of the distance from the axis. For example... Figure 2 As shown, when the distance to the sound source increases from R to R2 (twice the distance to R), the area of ​​the wavefront increases from A to 2A, and the sound intensity decreases to half. Due to the low transmission attenuation of line source speakers, they can achieve greater sound reinforcement efficiency over longer distances. Good high-frequency coupling characteristics reduce distortion caused by interference, which is beneficial for high-quality sound reinforcement. When a string of line source speakers is operating, directivity control is better; the more speakers there are in the vertical direction, the lower the controllable frequency of directivity.

[0005] Following market demands, various manufacturers have designed line-source-based array speaker products for use in professional audio reinforcement. For example, US7965857B2, a related patent to US2007 / 0160233A1, discloses a ribbon tweeter driver suitable for line-source sound reinforcement applications. According to the specification and drawings of US2007 / 0160233A1, the loudspeaker comprises two identical metal housings with two extending slots or sound channels that allow the sound produced by the loudspeaker to propagate outwards. A horn can be connected to the loudspeaker, providing a gradually widening wavefront.

[0006] In addition, many manufacturers have designed horn waveguides based on compression actuators that approximate the shape of planar waves, using cylindrical wave conversion. The earliest example is represented by patent US5163167A, proposed by Heil Christian of France. The specification and drawings of US5163167A indicate that the waveguide consists of three elements: two elements are symmetrical along a vertical plane and include a housing with a fixed inner core. Each housing includes a rear plate and a front plate connected by a central plate. There is an opening between the front plates, and the housing covers the inner core with gaps. This patent discloses a geometric interpretation where, from the circular outlet of the compression actuator through a channel groove composed of parabolic and hyperboloid surfaces to the rectangular outlet, the wavefront passes the phase plug surface at approximately equal times. That is, the path difference (δ) between the allowable acoustic path between the compression actuator through the circular aperture and the wavefront leading to the rectangular outlet in the waveguide is: δ≤λ / 4 (λ is the wavelength of the highest usable frequency of the design target). The error is less than or equal to one-quarter of the wavelength of the highest operating frequency, but of course, it will not be absolutely identical. The error is small enough to be within an acceptable range that is permissible for the frequency of product design work.

[0007] The two types of line array sound sources mentioned above can only achieve vertical array coupling of single sound source speakers, as shown in Figure 13 of US5163167A. Furthermore, the two vertical sound sources must operate within the same frequency range; otherwise, continuous coherent sound waves cannot be generated. A qualified line sound source has a rectangular aperture size w that is less than or equal to its design target highest frequency wavelength, i.e., W ≤ λ. For example, in US2007 / 0160233A1 patent, the rectangular exit width of the ribbon tweeter is 18mm, and in US5163167A patent, the rectangular exit width of the waveguide is 18mm. Based on W ≤ λ, its maximum operating frequency can be calculated to be 19kHz.

[0008] To satisfy the coupling condition, the center distance M between two adjacent sound sources should be less than or equal to half the wavelength of the upper frequency limit, i.e., M ≤ λ / 2. Therefore, when the upper coupling frequency limit of the tweeter is Fh = 18kHz, the center distance M of its sound sources can be calculated based on Fh = 18kHz and the speed of sound V0 = 343 m / s, where M ≤ 9.5 mm. Figure 3A As shown, when the two ribbon tweeters 6 are arranged horizontally, and the distance between their sound sources M is 109 mm, the corresponding upper coupling frequency Fh = 3155 Hz. Figure 3A The interference between the two ribbon tweeters is shown. The straight line indicates that frequencies below 3155 Hz propagate in a plane wave pattern, while frequencies above 3155 Hz begin to show comb-like filtering interference.

[0009] like Figure 3B As shown, when the two compressed tweeters 8 are horizontally arranged via waveguide 10 as in US5163167A patent, and the center distance M between their sound sources is 18 mm, the corresponding upper coupling frequency Fh = 9555 Hz. Figure 3B The interference between the two waveguides is shown. The straight line indicates that the waveguides propagate in a plane wave pattern at frequencies below 9555 Hz, while interference begins to appear at frequencies above 9555 Hz.

[0010] It is evident that, due to physical structural issues, neither ribbon tweeters nor cylindrical wave converters, as represented by the French company Heil Christian, can achieve perfect horizontal coupling of multiple drivers. The expected usable frequency is less than 10kHz, far less than the 18kHz required for single vertical coupling. Summary of the Invention

[0011] To address the problem that current industry-standard line sound source technologies, as exemplified above, cannot achieve perfect horizontal coupling, this invention, while achieving perfect horizontal coupling, also accomplishes the following objectives:

[0012] Another object of the present invention is to provide a periscope-type reflective horn that enables two or more compression driver (high-pitched or mid-pitched driver) sound sources to be non-coupling in the horizontal position wavefront through a specific reflective sound wave channel slot, and converts the sound wave into a plane wave shape without acoustic interference.

[0013] Another objective of this invention is to provide a method for increasing sound pressure level output, wherein multiple driver waveguides operating simultaneously at the same frequency within a speaker enclosure are not coupled in a common cavity, which increases the maximum sound pressure level by ≥6dB compared to the current industry technology where a single driver is vertically coupled to a waveguide.

[0014] Another object of the present invention is to provide a method that allows multiple driver acoustic sources operating in the same frequency range to generate common wavefront coupling at the same horizontal position without sharing a cavity, and with almost zero acoustic interference.

[0015] Another object of the present invention is to provide a method that allows multiple driver acoustic sources operating in different frequency ranges to generate common coupling without sharing a cavity at the same horizontal position on the wavefront, with almost zero acoustic interference.

[0016] Another object of the present invention is to provide a method for generating one or more wavefronts within one or more frequency ranges in a speaker enclosure, the wavefronts coupling acoustic waves of the same frequency range in adjacent speaker enclosures via a line array without acoustic interference.

[0017] This invention provides a dual-source wavefront non-co-cavity horizontally coupled tweeter waveguide. The waveguide is Y-shaped and includes two horizontally arranged waveguide channels. The waveguide channels are used to connect to a spherical wave tweeter driver. The waveguide channels are composed of a first channel, a first reflecting surface, a second channel, a second reflecting surface, and a third channel connected in sequence. The first channel is composed of a parabolic surface, the first reflecting surface is composed of an elliptical surface, the second channel is composed of a hyperboloid surface, and the third channel is composed of a rectangular surface.

[0018] As an improvement, the first channel is composed of a pair of mutually fitted convex parabolic surfaces and concave parabolic surfaces. The first channel is formed by the space between the two parabolic surfaces. The parabola of the concave parabolic surface at its end is the parabola of the elliptical section of the first reflecting surface. The parabola of the elliptical section at the end of the first reflecting surface is the parabola of one hyperboloid section of the second channel. The convex parabolic surface is divided into a right-angled cone with a vertex angle less than or equal to 90°. The parabola of its end is the parabola of the second hyperboloid section of the second channel.

[0019] As an improvement, the second channel is connected to the first channel through the first reflective surface, and the second channel is connected to the third channel through the second reflective surface. The second channel is located between the first reflective surface and the second reflective surface.

[0020] As an improvement, the first reflecting surface is located at the end of the first channel. The first reflecting surface is an elliptical reflecting surface. The second reflecting surface is a rectangular plane. In the horizontal cross-sectional view, the second channel is composed of parallel inner and outer walls. The inlet end of the inner wall of the second channel is connected to the first reflecting surface. The inlet end of the outer wall of the second channel is connected to the convex parabolic surface. The outlet end of the outer wall of the second channel is connected to the second reflecting surface.

[0021] As an improvement, the sound wave passes through the first channel, the first reflecting surface, the second channel, the second reflecting surface, and the third channel. The sound wave passing through the first reflecting surface and the second reflecting surface conforms to the law of reflection, that is, the incident angle is equal to the reflection angle: θi1=θr1=θi2=θr2. The path difference (δ) between the sound waves passing through the waveguide channels is: δ≤λ / 4.

[0022] As an improvement, in the horizontal cross-sectional view, the third channel is composed of the inner wall of the third channel and the outer wall of the third channel.

[0023] As an improvement, the entrance end of the outer wall of the third channel is connected to the second reflective surface, and the entrance end of the inner wall of the third channel is connected to the inner wall of the reflective channel.

[0024] As an improvement, on the horizontal plane passing through the center of the waveguide, the centerline of the first channel is parallel to the outer wall of the third channel, the inner wall of the third channel is in the shape of a broken line, the entrance section of the inner wall of the third channel is parallel to the outer wall of the third channel, and one end of the exit section of the inner wall of the third channel is connected to the entrance section of the inner wall of the third channel, and the other end is connected to the exit of the third channel.

[0025] As an improvement, the present invention provides a high-frequency horn, comprising a dual-source wavefront non-co-cavity horizontally coupled high-frequency waveguide, and two high-frequency drivers installed at the inlet end of the waveguide channel.

[0026] As an improvement, the present invention provides a speaker, including a tweeter, two mid-bass drivers arranged horizontally and symmetrically on both sides of the tweeter, and a cabinet.

[0027] like Figure 3C As shown, the waveguide 12 designed according to the present invention has a rectangular opening width W of 18 mm when the two spherical wave tweeter drivers 14 are arranged horizontally. According to W≤λ, its maximum operating frequency can be calculated to be 19KHz. Figure 3C The waveguide designed and implemented in this invention exhibits planar wave propagation without acoustic interference at frequencies below 19kHz. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a point sound source and a spherical wave.

[0029] Figure 2 This is a schematic diagram of a line sound source and a cylindrical wave.

[0030] Figure 3A This is a schematic diagram of two ribbon tweeters horizontally coupled.

[0031] Figure 3B This is a schematic diagram of two tweeters horizontally coupled via a conventional waveguide.

[0032] Figure 3C This is a schematic diagram of the horizontal coupling between the waveguide and the high-frequency sound source of the present invention.

[0033] Figure 4 This is a cross-sectional view of the high-pitched horn of the present invention on a horizontal plane passing through the center of the waveguide.

[0034] Figure 4A This is a schematic diagram of the inner wall of the waveguide channel of the waveguide of the present invention.

[0035] Figure 4B This is a schematic diagram of the outer wall of the waveguide channel of the waveguide of the present invention.

[0036] Figure 4C This is a schematic diagram of the propagation path and reflection relationship of acoustic rays in the waveguide channel of this invention.

[0037] Figure 5 This is a three-dimensional schematic diagram of the waveguide outer shell of the present invention.

[0038] Figure 6A This is a horizontal cross-sectional view of the waveguide of this invention applied to speaker design.

[0039] Figure 6B This is a front view of the waveguide of this invention applied to speaker design.

[0040] Figure 7 This is a comparison chart of the test curves of the waveguide of this invention and existing technologies under the same test conditions.

[0041] Figure 8A It is a 3D directivity diagram of the waveguide in the existing technology.

[0042] Figure 8B It is a vertical 3D directivity diagram of existing waveguide technology.

[0043] Figure 9A This is a 3D directivity diagram of the waveguide in an embodiment of the present invention.

[0044] Figure 9B This is a vertical 3D directivity diagram of the waveguide in an embodiment of the present invention.

[0045] Figure 10 This is a comparison curve of sound pressure level under the same test conditions as existing technologies in an embodiment of the present invention.

[0046] Figure 11A and Figure 11B This invention uses two identical drivers operating in the same frequency band.

[0047] Figure 12A and Figure 12B This invention uses two different drivers operating in different frequency bands, and the frequency response curves are shown.

[0048] Figure 13A This is a schematic diagram of a speaker vertical array combination designed according to the waveguide application of the present invention.

[0049] Figure 13B and Figure 13C This is a diagram illustrating the coupling of the waveguide in a vertical array of speakers according to the present invention. Detailed Implementation

[0050] The present invention will now be further described with reference to the accompanying drawings.

[0051] like Figure 1The diagram illustrates a point sound source and a spherical wave. Point sound source 2 produces a wavefront that is a concentric sphere, referred to as a spherical wave. Imagine a spherical sound source in an infinitely uniform medium. Its surface rapidly expands and contracts, and all points on the surface vibrate with the same phase and amplitude. The wave radiated into the surrounding medium is a spherical wave. This type of sound wave is spherically symmetric, meaning the sound pressure level depends only on the distance from the center of the sphere. Any sound source of any shape, as long as its size is much smaller than the wavelength, can be considered a point sound source, radiating spherical waves. For spherical waves, the sound intensity at any distance from the sound source is inversely proportional to the square of the distance. As shown in the diagram, when the distance from the sound source increases from R to R2 (twice the distance of R), the area of ​​the wavefront increases from A to 4A, and the sound intensity decreases to 1 / 4.

[0052] like Figure 2 The diagram illustrates a line sound source and a cylindrical wave. The line sound source 4 generates a wave whose wavefront is a coaxial cylindrical surface, referred to as a cylindrical wave. A cylindrical wave is a wave whose wavefront is a coaxial cylindrical surface. Imagine an infinitely long, uniform line sound source in an infinitely uniform medium; the wave it produces would be an ideal cylindrical sound wave. In a cylindrical sound wave, the sound pressure amplitude is uniformly distributed along the axial direction and inversely proportional to the square root of the distance from the axis along the radial direction. Its radial sound intensity is inversely proportional to the first power of the distance from the axis. As shown in the diagram, when the sound source distance increases from R to R2 (twice the distance of R), the area of ​​the wavefront increases from A to 2A, and the sound intensity decreases to 1 / 2.

[0053] like Figure 3A As shown, when two ribbon tweeters 6 are arranged horizontally, due to the size limitation of the ribbon tweeters, when the distance between their sound sources M is 109 mm, the corresponding upper limit of coupling frequency Fh = 3155 Hz. Figure 3A The interference between the two ribbon tweeters is shown. The straight line indicates that frequencies below 3155 Hz propagate in a plane wave pattern, while frequencies above 3155 Hz begin to show comb-like filtering interference.

[0054] like Figure 3B As shown, when the two compressed tweeters 8 are horizontally arranged via waveguide 10 as in US5163167A patent, and the center distance M between their sound sources is 18 mm, the corresponding upper coupling frequency Fh = 9555 Hz. Figure 3B The interference between the two waveguides is shown. The straight line indicates that the waveguides propagate in a plane wave pattern at frequencies below 9555 Hz, while interference begins to appear at frequencies above 9555 Hz.

[0055] like Figure 3C As shown, the waveguide 12 designed according to the present invention has a rectangular opening width W of 18 mm when the two spherical wave tweeter drivers 14 are arranged horizontally. According to W≤λ, its maximum operating frequency can be calculated to be 19KHz. Figure 3C The waveguide designed and implemented in this invention exhibits planar wave propagation without acoustic interference at frequencies below 19kHz.

[0056] like Figure 4 As shown, the present invention provides a tweeter horn 16 comprising a dual-source wavefront non-co-cavity horizontally coupled tweeter waveguide 18 and two spherical wave tweeter drivers 14 installed at the entrance end of the waveguide channel 20. The waveguide 18 is Y-shaped and includes two horizontally arranged waveguide channels 20. The waveguide channels 20 are used to connect the spherical wave tweeter drivers 14. The waveguide channel 20 is composed of a first channel 22, a first reflecting surface 24, a second channel 26, a second reflecting surface 28, and a third channel 30 connected in sequence. The first channel 22 is parabolic, the first reflecting surface 24 is elliptical, the second channel 26 is hyperboloid, and the third channel 30 is rectangular. The first channel 22 is composed of a pair of mutually fitted convex and concave parabolic surfaces, and the space between the two parabolic surfaces constitutes the first channel 22.

[0057] like Figure 4 As shown, the second channel 26 is connected to the first channel 22 via the first reflecting surface 24, and to the third channel 30 via the second reflecting surface 28. The second channel 26 is located between the first reflecting surface 24 and the second reflecting surface 28. The first reflecting surface 24 is located at the end of the first channel 22 and is an elliptical reflecting surface. The second reflecting surface 28 is a rectangular plane. In the horizontal cross-sectional view, the second channel 26 is composed of a parallel inner wall 36 and an outer wall 38. The inlet end of the inner wall 36 is connected to the first reflecting surface 24, the inlet end of the outer wall 38 is connected to the convex parabolic surface 34, and the outlet end of the outer wall 38 is connected to the second reflecting surface 28.

[0058] like Figure 4 As shown, in the horizontal cross-sectional view, the third channel 30 is composed of an inner wall 40 and an outer wall 42. The entrance end of the outer wall 42 is connected to the second reflecting surface 28, and the entrance end of the inner wall 40 is connected to the inner wall 36 of the second channel. On the horizontal plane passing through the center of the waveguide, the centerline AB of the first channel is parallel to the outer wall 42 of the third channel. The inner wall 40 of the third channel is zigzag-shaped, with its entrance section parallel to the outer wall 42. One end of the exit section of the inner wall 40 is connected to the entrance section of the inner wall, and the other end is connected to the exit 44 of the third channel. As an alternative, the inner wall 40 of the third channel can be a straight line, with one end connected to the inner wall 36 of the second channel and the other end connected to the exit 44 of the third channel.

[0059] like Figure 4A As shown, Figure 4AThis is a schematic diagram showing the connection relationship between the concave parabolic surface and the first reflecting surface of the waveguide of the present invention. The parabolic curve 33 of the parabolic section at the end of the concave parabolic surface 32 is a partial parabolic curve of the elliptical section of the first reflecting surface 24. The parabolic curve 35 of the end section of the elliptical surface of the first reflecting surface 24 is a partial parabolic curve of a hyperboloid section of the second channel 26.

[0060] like Figure 4B As shown, Figure 4B This is a schematic diagram of the convex parabolic surface of the waveguide of the present invention. The convex parabolic surface 34 is part of a right-angled cone, the angle of its vertex A0 is less than or equal to 90°, and the parabola 37 of the cross section of its end parabolic surface 34 is the parabola of the second hyperboloid cross section of the second channel 26.

[0061] like Figure 4C As shown, Figure 4C This is a schematic diagram of the propagation path and reflection relationship of the waveguide acoustic ray of the present invention. The acoustic ray AB passes through the first channel 22, the first reflecting surface 24, the second channel 26, the second reflecting surface 28, and the third channel 30. The acoustic ray passing through the first reflecting surface 24 and the second reflecting surface 28 conforms to the law of reflection, that is, the incident angle is equal to the reflection angle: θi1=θr1=θi2=θr2. The path difference (δ) between the waveguide channels is: δ≤λ / 4.

[0062] like Figure 4CAs shown, point A is any point on the emitting surface of the tweeter 14; point B is any point on the first reflecting surface 24 where the sound wave first contacts; point C is any point on the second reflecting surface 28 where the sound wave first contacts; point D is the position where the sound wave arrives after being reflected by the second reflecting surface 28; line segment AB represents the path of the sound wave in the first channel 22; line segment BC represents the path of the sound wave in the second channel 26; line segment CD represents the path of the sound wave in the third channel. The path of the sound wave in the waveguide channel 20 has the following relationship: (1) The sound wave is emitted from any point A on the emitting surface of the tweeter 20, along the path AB, and passes through any point B on the first reflecting surface 24. (2) BN is the normal perpendicular to point B on the first reflecting surface 24. (3) The incident angle θi1 is the angle between the sound wave line segment AB, i.e., the path of the incident wave, and the normal. (4) The sound wave is reflected at point B on the first reflecting surface 24 and continues to propagate along the path BC, which is the reflection path of the sound wave. (5) Reflection angle θr1, which is the angle between the sound wave line segment BC, i.e., the path of the reflected wave, and the normal. (6) The sound wave reaches any point C on the second reflecting surface 28 along the path BC. (7) CN is the normal perpendicular to point C on the second reflecting surface 28. (8) Incident angle θi2, which is the angle between the sound wave line segment BC, i.e., the path of the reflected wave, and the normal. (9) The sound wave is reflected at any point C on the second reflecting surface 28 and continues to propagate along the path CD, which is the reflection path of the sound wave. (10) Reflection angle θr2, which is the angle between the sound wave line segment CD, i.e., the path of the reflected wave, and the normal. (11) The first reflecting surface 24 is parallel to the second reflecting surface 28. The two normals BN and CN are perpendicular to the two reflecting surfaces, so the normals BN and CN are also parallel. Therefore, (12) according to the law of reflection, θi1 = θr1, θi2 = θr2. (13) Since they are alternate interior angles, θ5 = θ6. (13) Also, since θr1 + θ5 = θi2 + θ6 = 90°, and they are supplementary angles, θr1 = θi2. Finally, we can conclude that θi1 = θr1 = θi2 = θr2.

[0063] like Figure 4 As shown, waveguide 18 includes three housings: a convex parabolic surface 34, a second channel outer wall 38, a second reflecting surface 28, and a third channel outer wall 42, which are connected in sequence to form two outer housings symmetrical about the vertical plane. A concave parabolic surface 32, a first reflecting surface 24, a second channel inner wall 36, and a third channel inner wall 40, which are connected in sequence to form an inner housing symmetrical about the vertical plane. The space between the outer and inner housings forms the interconnected first channel 22, second channel 26, and third channel 30. The internal structure geometry of the channels varies, including rectangular surfaces, parabolic surfaces, or related curved surface features. A flange is located at the entrance end of the first channel 22, allowing the tweeter 20 to be connected to the entrance end of the first channel 22 using screws through a through-hole in the flange.

[0064] As an improvement, equally divided grids (not shown in the figure) can be added to the first channel 22, the second channel 26, and the third channel 30. This can improve the strength of the components, suppress resonance caused by the physical properties of the materials under high sound pressure, reduce unnecessary diffraction of sound waves in the sound wave channels, increase the effective high frequency limit, and reduce distortion.

[0065] This invention relates to an acoustic wave coupling waveguide. It is designed based on the principles of geometric acoustics, specifically the acoustic field based on ray theory. Therefore, this invention utilizes the fact that known physical laws of optics also apply to sound propagation, such as the law of reflection and Fermat's shortest time principle. The parabolic, hyperboloid, and elliptical surfaces used in this invention can all be obtained by truncating a conical cross-section (referring to a surface generated by rotating a curve from a cone). More specifically, in the context of this invention, surfaces with the following geometric characteristics—rectangular, hyperboloid, parabolic, or elliptical—are used to reflect sound waves to complete the design. It includes a periscope waveguide with multiple acoustic channels, the channels having a periscope structure, and the interior consisting of multiple channels composed of various shaped structures with distinct geometric features.

[0066] like Figure 4 As shown in the diagram, the acoustic wave reflection paths inside waveguide 18 are related as follows: Point A is the center point on the emitting surface of tweeter driver 20, point B is the midpoint of the first reflecting surface 24, point C is the midpoint of the second reflecting surface 28, and point D is the midpoint of the waveguide outlet. Line segment AB represents the first acoustic wave channel 22 path, line segment BC represents the second acoustic wave channel 26 path, and line segment CD represents the third acoustic wave channel 30 path.

[0067] Correspondingly, the sound wave entering from the sound source 20 along the emitting surface via path AB is a parallel ray. After being reflected by the first reflecting surface 24, the sound wave propagates along path BC, also remaining a parallel ray. After being reflected again by the second reflecting surface 28, it still remains a parallel ray. The parallel sound wave rays essentially eliminate diffraction, which is detrimental to sound transmission coupling. This is a significant advantage of this invention compared to other waveguide structures.

[0068] Meanwhile, along the paths AB, BC, and CD of the sound wave, the incident ray AB, the reflected ray BC, the reflected ray CD, and the normal all lie on the same plane, which is also one of the conditions of the law of reflection.

[0069] According to Fermat's principle of shortest time, the path of light (or, in the case of this waveguide structure, sound waves) from one point to another will be the path that minimizes the propagation time. In situations such as... Figure 4Under the conditions shown, the sound wave will choose the path that minimizes the total propagation time from A to D. Assuming the speed of the sound wave in the medium is v, the time t from A to B, then to C, and finally to D is: t = AB / v + BC / v + CD / v = (AB + BC + CD) / v. This time will be minimized when the angle of incidence equals the angle of reflection for AB and BC, CD. This is because, given a fixed length of AB + BC + CD, the path from AB to BC, CD is shortest when the angle of incidence equals the angle of reflection, resulting in minimal sound wave propagation attenuation.

[0070] Based on the above, it can be deduced that in this invention, the sound rays from the emitting surface A to the wavefront D point all travel along the shortest straight path. In this invention, the time T from the emitting surface A to the wavefront D point is equal. When the time T is equal, the sound waves in the sound wave paths AB, BC, and CD are all in phase, that is, they are all equal-phase and equidistant cylindrical waves of a linear sound source.

[0071] In this invention, it is understood that the acoustic waveguide channel guides the sound source ray and corrects the sound wave path. This is not limited to the aforementioned conical (curved) or rectangular structures; other (reflective) surfaces can also be used. It is understood that the waveguide channel's reflective surface can be multi-channel, manifold, flat, annular parabolic, hyperbolic, or elliptical; or more generally, flat, concave, or convex, for example, annular, parabolic, or various other structural methods such as multi-channel or manifold.

[0072] The accuracy of the upper limit of usable frequency for a waveguide is often used as a measure of a successful design, especially for ultra-high frequencies with very short wavelengths. The waveguide acoustic channel design, within the necessary effective frequency range and the wavelength of the associated operating frequency, limits the width of the associated acoustic channel and the overall height of the waveguide.

[0073] like Figure 4 As shown, the following geometric path relationships exist in the sound wave paths AB, BC, and CD: (1) The lengths of the concave parabolic surface 32 and the convex parabolic surface 34 are equal; (2) The lengths of the first reflecting surface 24 and the second reflecting surface 28 are equal; (3) The lengths of the inner wall 36 of the second channel and the outer wall 38 of the second channel are equal; (4) The difference between the length of the inner wall 40 of the third channel and the length of the outer wall 42 of the third channel needs to be less than the distance from the end of the outer wall 42 of the third channel to the end 44 of the third channel.

[0074] like Figure 5As shown, the convex parabolic surface 34, the outer wall of the second channel 38, the second reflecting surface 28, and the outer wall of the third channel 42 are connected in sequence to form two outer shells that are symmetrical about the vertical plane. The total height of the waveguide outlet corresponding to the outer shell is H. The following geometric path relationship exists in the sound wave paths AB, BC, and CD: L = Ln, where L = AB + BC + CD is the total length of the path from point A of the sound source emitting surface of the waveguide to point D of the waveguide outlet, and Ln = ABn + BCn + CDn is the total length of the path from any point A of the sound source emitting surface of the waveguide to any point D at the height H of the waveguide outlet.

[0075] In addition, such as Figure 4 As shown, when the diameter of the emitting surface of the tweeter 20 is greater than the spatial width of the sound channel, the concave parabolic surface 32 needs to adjust the right-angled cone of the convex parabolic surface and the generatrix to be an arc during the fitting process of the convex parabolic surface 34. The distance between the two parabolic surfaces gradually transitions from the diameter of the emitting surface of the tweeter 20 to the spatial width required at the outlet end of the first channel 22.

[0076] like Figure 4 As shown, based on the operating parameters of the selected tweeter 20, the following design can be made according to the acoustic relationship. (1) Based on the wavelength λ of the highest usable frequency of the waveguide design target, the total width W of the rectangular plane output port at the waveguide outlet end can be calculated, where W1 + W2 = λ = W, and W1 and W2 are the widths of the left and right outlets of the waveguide, respectively. For example, if the highest usable frequency of the waveguide design target is 20KHz and the sound propagation speed is 343.2m / s, then the corresponding wavelength λ of the highest usable frequency is equal to 17.16 mm. Accordingly, the total width W of the rectangular plane output port at the waveguide outlet end is equal to 17.16 mm. If the channel design on both sides of the waveguide is consistent, then W1 = W2 = 8.58 mm. (2) Based on the wavelengths λ3 and λ4 of the highest usable frequency of the waveguide design target on the left and right sides, the width W3 of the left reflection channel 26 and the width W4 of the right reflection channel 26 of the waveguide can be calculated, where W3 = λ3 and W4 = λ4. For example, if the highest usable frequency wavelengths λ3 and λ4 on both sides of the waveguide are equal and both 20 kHz, and the speed of sound is taken as 343.2 m / s, then the corresponding highest usable frequency wavelengths λ3 and λ4 are equal to 17.16 mm. Accordingly, W3 = W4 = 17.16 mm. If, according to specific acoustic application requirements, the highest usable frequency wavelengths λ3 and λ4 on the left and right sides of the waveguide are not equal, then W3 and W4 need to be calculated separately.

[0077] like Figure 5As shown, based on the minimum usable frequency wavelength λ5 of the waveguide design target, the total height H of the rectangular planar output port at the waveguide outlet end can be calculated, where H ≥ λ5 / 2. For example, if the minimum usable frequency of the waveguide design target is 800Hz, and the speed of sound is taken as 343.2m / s, then the corresponding minimum usable frequency wavelength λ is equal to 429 mm. Accordingly, according to H ≥ λ5 / 2, the total height H of the rectangular planar output port at the waveguide outlet end is equal to 214.5 mm.

[0078] like Figure 4 As shown, the widths of W1 and W2 are obtained by correcting the third channel 30. Where: W1 = W3 / 2, W2 = W4 / 2. On the horizontal plane passing through the waveguide center, the centerline AB of the first channel is parallel to the outer wall 42 of the third channel. The inner wall 40 of the third channel is a broken line. The entrance section of the inner wall 40 is parallel to the outer wall 42 of the third channel. One end of the exit section of the third channel 40 connects to the entrance section of the inner wall 40, and the other end connects to the end 44 of the third channel. As an alternative, the inner wall 40 of the third channel can be a straight line, with one end connected to the inner wall 36 of the second channel and the other end connected to the exit 44 of the third channel 30.

[0079] like Figure 4 As shown, in the cylindrical mode propagation of sound waves, the axis of the cylinder is perpendicular, making the output rectangle an equiphase plane, which requires the following conditions to be met: (1) When the two tweeters 20 are working in the same frequency band, W3=W4≤W1+W2≤W. (2) When the two tweeters are working in different frequency bands, W1+W2=W.

[0080] like Figure 5 As shown, δ is the maximum length deviation between acoustic paths of the waveguide design target available frequency, that is, the path difference on L from any point A to any point D on the sound wave emitting surface. For effective coupling, δ needs to be less than a quarter wavelength of the highest design target available effective frequency, i.e.: δ≤λ / 4.

[0081] like Figure 5 As shown, in order for the propagation to be effectively cylindrical along the vertical axis, it is necessary for H to be greater than or equal to λ5.

[0082] like Figure 4 As shown, A1 < A2 < A3, where A1 is the angle between the two first reflecting surfaces 24 and the tangents to the midpoint B of the horizontal plane passing through the center of the waveguide. A2 is the angle between the two inner walls 36 of the second channel at the entrance end. A3 is the angle between the exit sections of the two inner walls 40 of the third channel at the end 44 of the third channel.

[0083] According to one embodiment of the present invention, the highest usable frequency wavelength λ=18kHz is selected, and correspondingly, W=18 mm. Two identical tweeters 20 are selected, W1=9mm, W2=9 mm, W3=18 mm, and W4=18 mm.

[0084] like Figure 4 As shown, the emitter diameter of the tweeter 20 is 35mm. Therefore, during the process of fitting the concave parabolic surface 34 to the convex parabolic surface 34, the distance between the two parabolic surfaces gradually decreases from the emitter diameter of the tweeter 20 of 35mm to 18mm at the outlet end of the first channel 22, so as to facilitate the propagation of sound waves in the channel of the waveguide 18 in the form of cylindrical waves.

[0085] like Figure 4 As shown, the tangent line between the first reflecting surface 24 and the midpoint B of the horizontal plane passing through the center of the waveguide is parallel to the second reflecting surface 28. The sound wave reflected from the first reflecting surface 24 to the second channel 26 conforms to the law of reflection, i.e., the angle of incidence equals the angle of reflection: θi1=θr1=θi2=θr2. Therefore, the angles of incidence and reflection for both reflections can be selected as 45°, thus forming a periscope-type reflection system.

[0086] like Figure 5 As shown, the physical path length L = 210 mm from the sound source emitting surface A to the wavefront output D' at the horizontal center, and the length Ln = 210 mm at any point on the physical path from the sound source emitting surface A to the wavefront output Dn, which satisfies the requirement of equidistant propagation of sound waves.

[0087] like Figure 5 As shown, the minimum usable frequency wavelength λ5 of the waveguide design target is selected, and the total height H of the rectangular plane output port at the waveguide outlet end is 210 mm, corresponding to a minimum usable frequency of approximately 800 Hz for the waveguide design target.

[0088] It should be understood that these dimensions are not limiting, but are simply examples of implementing the invention by way of example.

[0089] like Figure 6A As shown in the horizontal cross-sectional view of the speaker 45 using the waveguide design of this invention, the waveguide 18 of this invention is centered in the cabinet 46. The cross-section of the waveguide 18 shows that the left and right acoustic channels have a periscope structure. The entrance ends of the two acoustic channels of the waveguide 18 are respectively connected to the tweeter driver 20, forming the tweeter horn 16. The mid-bass drivers 48 are horizontally symmetrically arranged and mounted on the panel 50.

[0090] like Figure 6BAs shown, when viewed from the front of the housing 46, one can see the outlet section 44 of the inner wall of the third channel, the hollow periscope-like acoustic channel groove between the inner wall of the third channel and the outer wall of the third channel, and the acoustic output groove 54 formed by the rectangular cut 52 of the panel 50, which is the wavefront outlet.

[0091] The technical advantages of this invention can be demonstrated by comparison with existing technologies.

[0092] US Patent US20110085692A1 discloses a dual-diaphragm driver. As shown in the accompanying drawings, its wavefront consists of two annular planar diaphragms. The two diaphragms of the same diameter operate simultaneously in the same frequency band and are output through common cavity coupling.

[0093] US Patent US20130243232A1 discloses a dual-diaphragm driver with waveguide output, wherein the two diaphragms can have the same diameter or different diameters, and the acoustic waves of the diaphragms are output via wavefront coupling through a common cavity.

[0094] The final result of implementing the above two schemes into the product is: (1) The two diaphragms work in the same frequency band, and the maximum sound pressure level increases by 6dB (the calculation formula is L_max = L + 20 * log20(n), where L represents the sound pressure level of a single speaker and n represents the number of drivers). The effective usable frequency range is generally 800Hz-20KHz; (2) The two diaphragms work in different frequency bands (the extended working frequency band can reach 300Hz-20KHz). The effective usable frequency range of the small-sized diaphragm is 3KHz-20KHz, and the effective usable frequency range of the large-sized diaphragm is at least 300Hz-6KHz.

[0095] The advantage of both inventions is their relatively compact structure. Sound waves are mechanical waves that propagate through the mechanical vibrations of molecules and particles in a medium. They propagate as longitudinal waves, transferring energy through the interactions between molecules. Sound waves cause changes in air pressure as they propagate through the air. When a sound source vibrates, it produces continuous compression and rarefaction vibrations, forming sound waves. These vibrations cause the movement of air molecules, leading to changes in air pressure. During sound wave propagation through the air, the vibration of the sound source causes compression and rarefaction of the surrounding air molecules. When the sound source vibrates outwards, it pushes air molecules together, forming a compressed region and increasing pressure. When the sound source vibrates inwards, it pulls air molecules apart, forming a rarefaction region and decreasing pressure. This periodic pressure change propagates along the direction of sound wave propagation.

[0096] As can be seen from the two patented structures above, the diaphragms both operate simultaneously within a shared cavity, with wavefront coupling occurring within the cavity. When the driver operates at high power, the pressure within the cavity changes, causing variations in acoustic impedance and resulting in nonlinear distortion, which is particularly pronounced at high power. The physical characteristics of the diaphragm vary: a thinner diaphragm results in better high-frequency transient response; however, insufficient rigidity of the diaphragm material can easily lead to nonlinear distortion at high power. A thicker diaphragm provides better mid-frequency response but lower high-frequency efficiency, with severe attenuation in the 8kHz-20kHz range, reaching approximately 10dB. When a single diaphragm operates, the cavity pressure is P; when two diaphragms operate, the pressure doubles to 2P. In this case, the only solution is to increase the diaphragm thickness to address the distortion caused by the doubled cavity pressure. However, this increased thickness leads to lower high-frequency efficiency.

[0097] like Figure 7 As shown in the figure, the test curves of the mass-produced driver in US20110085692A1 patent and the waveguide of this invention are compared under the same test conditions. Among them, the curve of the mass-produced driver in US20110085692A1 patent (marked at the curve inflection point A) and the waveguide curve of this invention (marked at the curve inflection point B) show that the efficiency of US20110085692A1 patent is relatively high in the 500Hz-5KHz frequency band, but the attenuation in the high-frequency 4KHz-20KHz range (marked by F box) is severe, reaching about 10dB. This is unfavorable for applications in line array sound reinforcement, and air attenuation in long-distance sound reinforcement is mainly in the high-frequency range of 4KHz-20KHz.

[0098] Similarly, the data sheet published in patent US20130243232A1 for a mass-produced compressed drive waveguide shows that its high-frequency diaphragm size is 1.75" (44.4 mm), the mid-high frequency diaphragm size is 3.5" (90 mm), and the operating frequency range is 400Hz - 22000 Hz. When the two diaphragms work together, the 1.75" high-frequency diaphragm is under the same pressure as the 3.5" (90 mm) mid-high frequency diaphragm, but the thickness of the diaphragms is different, which will cause high-frequency distortion. The higher the power, the greater the nonlinear distortion.

[0099] This invention achieves the same objective of the two patents through the following two methods:

[0100] (1) Two sound source drivers working in the same frequency band to extend the sound pressure level increases the maximum sound pressure level by 6dB (the calculation formula is L_max = L + 20 * log20(n), where L represents the sound pressure level of a single sound source driver and n represents the number of sound source drivers). The effective frequency band is generally 800Hz-20KHz.

[0101] (2) A method to extend the bandwidth by having two sound source drivers operate in different frequency bands (the extended operating frequency band can reach 300Hz-20KHz). The effective usable frequency band for small-sized diaphragms is 3KHz-20KHz, and the effective usable frequency band for large-sized diaphragms is at least 300Hz-6KHz. This invention solves the distortion problem caused by the above-mentioned physical defects in hardware by using a method of wavefront coupling between two sound source drivers without a common cavity. It also has the following advantages in application design:

[0102] (1) The method of this invention uses two sound source drivers that are compatible with any compression driver currently in mass production in the industry, including traditional mid-high frequency compression drivers and ribbon tweeters. However, the above two patents or similar patents cannot achieve this due to their physical structure or technical characteristics.

[0103] (2) The above two patent implementations are products of their own technology, with their own inherent technical features or sound style. However, in the implementation method of this invention, the two drivers can be designed and matched with mass-produced drivers from different manufacturers to obtain different sound styles and products. By designing the waveguide, different drivers can be matched with the speaker to obtain different sound styles and products.

[0104] (3) According to the present invention, two different sound source drivers are implemented and operate in different frequency bands, which can extend the frequency response. Due to the non-co-cavity structure of the wavefronts of the two sound source frequency bands, there is a wider bandwidth in the overlapping region, which is beneficial for R&D engineers to design flexible frequency division. In the prior art, the frequency response curve in the overlapping region has many peaks and valleys, and the selection of the frequency division point is very limited, which is not conducive to the flexible application of R&D personnel.

[0105] The waveguide of this invention is manufactured using a mold made of materials such as metal, ABS plastic, carbon fiber, and resin. Figure 4 As shown, waveguide 18 includes three housings: a convex parabolic surface 34, a second channel outer wall 38, a second reflecting surface 28, and a third channel outer wall 42 are sequentially connected to form two outer housings symmetrical about a vertical plane. A concave parabolic surface 32, a first reflecting surface 24, a second channel inner wall 36, and a third channel inner wall 40 are sequentially connected to form an inner housing symmetrical about a vertical plane. The space between the outer and inner housings forms the acoustic wave channel of waveguide 18. Additionally, the housing may include a flange for fixing the tweeter driver 20. These components can be assembled using processes such as gluing, thermal welding, screwing, or ultrasonic welding.

[0106] The waveguide of this invention has an internal geometry that ensures all or nearly all of the shortest paths from the tweeter's emitting surface to the output rectangular plane wave are of equal length. In waveguide design applications, the propagation time of sound waves through the periscope-like reflection channel slot is constant, and since the internal path is the shortest, there are no phenomena detrimental to sound wave propagation, such as sound wave diffraction.

[0107] Due to the precision issues in mold production, the path difference (δ) between the plane wavefronts from point A to point D of the sound source emission surface is: δ≤λ / 4, where λ is the wavelength of the highest usable frequency of the design target, that is, the path difference is less than or equal to one-quarter of the wavelength of the highest operating frequency.

[0108] Therefore, the waveguide of the present invention can convert equiphase spherical waves or cylindrical waves driven by two identical or different drivers into cylindrical equiphase waves coupled in a horizontal position, and the two cylindrical acoustic waves propagate in the form of cylindrical waves through horizontal wavefront coupling.

[0109] Figure 8A , Figure 8B , Figure 9A , Figure 9B The embodiments of this invention provide 3D directivity patterns of waveguides tested under the same conditions as existing technologies, wherein... Figure 8A It is a 3D directivity pattern of the waveguide in the existing technology. Figure 8B It is a 3D vertical pointing diagram of existing waveguide technology. Figure 9A This is a 3D horizontal pointing diagram of the waveguide according to an embodiment of the present invention. Figure 9B This is a 3D vertical pointing diagram of the waveguide according to an embodiment of the present invention. From... Figure 8A and Figure 9A The comparison reveals that the waveguide of this invention is basically consistent with the horizontal 3D directivity diagram of existing waveguides, and the directivity is more uniform around 16kHz, indicating that it achieves the designed target usable frequency and has higher accuracy than existing technologies. Figure 8B and Figure 9B The comparison reveals that the vertical 3D directivity diagram of the waveguide of the present invention is basically consistent with that of the existing waveguide. The higher the frequency, the narrower the directivity, and there are no other side lobes, which conforms to the directivity characteristics of a line source.

[0110] like Figure 10 As shown, the sound pressure level curves in the figure were obtained using the same driver unit, the same 110° directivity control horn, the same voltage, and under the same conditions. It can be seen that the sound pressure level curve A (marked with box A) of this invention is approximately 6dB higher than the existing waveguide curve B (marked with box B), and the usable frequency at the lower end is even lower, down to 800Hz, while the existing waveguide cuts off at around 1kHz. This technical advantage corresponds to another objective of this invention, namely, providing a method to increase sound pressure level output. This involves multiple driver waveguides operating simultaneously at the same frequency within the speaker enclosure, with wavefronts not co-cavity coupled. Compared to the current industry technology where a single driver is vertically coupled, the maximum sound pressure level of the waveguide will increase by ≥6dB.

[0111] like Figure 11A and Figure 11B As shown, Figure 11A and Figure 11BThis invention uses two identical drivers operating in the same frequency band. As shown in the figure, curve B (marked with box B) is the frequency response curve when a single driver is operating, curve A (marked with box A) is the coupling curve when both drivers are operating simultaneously, and curve C (marked with box C) is the phase curve. The sound pressure level (SPL) is calculated as: L_max = L + 20 * log20(n), where N represents the number of sound source drivers. When both drivers are operating simultaneously, the curves perfectly superimpose by 6dB, and their phase curves C are completely identical. As shown in the test results, there is no acoustic interference when the two sound sources reach wavefront coupling. This technical advantage corresponds to another objective of this invention: providing a waveguide that allows multiple driver sound sources operating in the same frequency range to generate common wavefront coupling at the same horizontal position without sharing a cavity, and with almost zero acoustic interference.

[0112] like Figure 12A and Figure 12B As shown, Figure 12A and Figure 12B This invention uses two different drivers operating in different frequency bands, as shown in the frequency response curves. As the figure shows, the high-frequency compression driver A (curve marked with box A) and the mid-frequency compression driver B (curve marked with box B) exhibit nearly identical trends at phase C (marked with box C). The usable frequency band for high-frequency compression driver A is 1kHz-18kHz, and the usable frequency band for mid-frequency compression driver B is 300Hz-9kHz. As indicated by the overlapping area F (marked with box F), the crossover point selection range for the two drivers is very wide, providing designers with greater flexibility in frequency division. This technical advantage corresponds to another objective of this invention: providing a waveguide that allows multiple driver sound sources operating in different frequency ranges to achieve common coupling without sharing a cavity at the same horizontal position on the wavefront, with virtually zero acoustic interference.

[0113] Figure 13A This is a schematic diagram of a speaker vertical array combination designed according to the waveguide application of the present invention. Figure 13B and Figure 13C This is a diagram illustrating the waveguide coupling of the present invention in a vertical array of speakers. (See diagram for example.) Figure 13A As shown, three speakers 45 are stacked vertically to form a vertical speaker array 56. Figure 13B and Figure 13C As shown, the combination of three waveguides 18 and sound sources 20 results in no interference coupling of cylindrical waves when the speakers are stacked vertically. The vertical coupling of multiple waveguides of this invention in a line array speaker provides another objective of this invention: to provide a waveguide that generates one or more wavefronts within one or more frequency ranges within a speaker, which couples acoustic waves of the same frequency range in adjacent vertically stacked line array speakers without acoustic interference.

Claims

1. A dual sound source wave front non-united horizontal coupling tweeter waveguide, characterized in that, The waveguide is Y-shaped and includes two horizontally arranged waveguide channels. The waveguide channels are used to connect to a spherical wave tweeter driver. The waveguide channels are composed of a first channel, a first reflecting surface, a second channel, a second reflecting surface, and a third channel connected in sequence. The first channel is composed of a parabola, the first reflecting surface is an elliptical surface, the second channel is composed of a hyperboloid, the second reflecting surface is a rectangular surface, and the third channel is a rectangular surface. The first channel is composed of a pair of mutually fitted convex and concave parabolic surfaces. The first channel is formed by the space between the two parabolic surfaces. The parabola at the end of the concave parabolic surface is the parabola of the elliptical surface of the first reflecting surface. The parabola at the end of the elliptical surface of the first reflecting surface is the parabola of one of the hyperboloid sections of the second channel. The convex parabolic surface is divided into a right-angled cone with a vertex angle less than or equal to 90°. The parabola at the end of the convex parabolic surface is the parabola of the second hyperboloid section of the second channel.

2. The dual sound source wave front un-coupled horizontal coupling tweeter waveguide of claim 1, wherein The second channel is connected to the first channel through the first reflective surface, and the second channel is connected to the third channel through the second reflective surface. The second channel is located between the first reflective surface and the second reflective surface.

3. The dual sound source wave front un-coupled horizontal coupling tweeter waveguide of claim 1, wherein The first reflective surface is located at the end of the first channel. The first reflective surface is an elliptical reflective surface. The second reflective surface is a rectangular plane. In the horizontal cross-sectional view, the second channel is composed of parallel inner and outer walls. The inlet end of the inner wall of the second channel is connected to the first reflective surface, the inlet end of the outer wall of the second channel is connected to the convex parabolic surface, and the outlet end of the outer wall of the second channel is connected to the second reflective surface.

4. The dual sound source wave front un-coupled horizontal coupling tweeter waveguide of claim 1, wherein The acoustic ray passes through the first channel, the first reflecting surface, the second channel, the second reflecting surface, and the third channel. The path difference δ between the acoustic waves passing through the waveguide channels is: δ≤λ / 4, where λ is the wavelength of the highest usable frequency of the design target.

5. The dual sound source wave front un-coupled horizontal coupling tweeter waveguide of claim 1, wherein The third channel, as described in the horizontal cross-sectional view, is composed of an inner wall and an outer wall.

6. A dual sound source wave front un-coupled horizontal coupling tweeter waveguide according to claim 5, wherein The outer wall entrance of the third channel is connected to the second reflective surface, and the inner wall entrance of the third channel is connected to the inner wall of the second channel.

7. The dual sound source wave front un-coupled horizontal coupling tweeter waveguide of claim 5, wherein On a horizontal plane passing through the center of the waveguide, the centerline of the first channel is parallel to the outer wall of the third channel. The inner wall of the third channel is in the shape of a broken line. The entrance section of the inner wall of the third channel is parallel to the outer wall of the third channel. One end of the exit section of the inner wall of the third channel is connected to the entrance section of the inner wall of the third channel, and the other end is connected to the exit of the third channel.

8. A tweeter horn, comprising a dual-source wavefront non-co-cavity horizontally coupled tweeter waveguide according to claim 1, and two tweeter drivers installed at the inlet end of the waveguide channel.

9. A speaker enclosure comprising a tweeter horn as claimed in claim 8, two mid-bass drivers arranged horizontally symmetrically on both sides of the tweeter horn, and an enclosure.

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