An adjustable vertical directional sound column

Abstract

The application provides a sound amplification sound column with adjustable vertical direction. The sound column comprises multiple coaxial cylindrical wave mid-high sound boxes arranged vertically, a sound box connecting mechanism, and a sound column direction adjusting mechanism. The sound box comprises a box with a trapezoidal vertical section and a coaxial cylindrical wave mid-high module installed on the panel of the box. The coaxial cylindrical wave mid-high module comprises a midrange horn, a high-frequency module, and a midrange phase plate. The high-frequency module is embedded in the midrange phase plate, and the midrange phase plate is placed on the midrange horn. The sound column is composed of multiple coaxial cylindrical wave mid-high sound boxes arranged vertically, and the curvature of the cylindrical wave is accurately controlled through the connecting mechanism and the adjusting mechanism to realize continuous adjustment of the vertical direction.

Description

Technical Field

[0001] The present invention relates to a sound amplification device, and more particularly to a sound amplification column with adjustable vertical directionality. The sound column is composed of a plurality of coaxial cylindrical wave mid-range and high-frequency speakers arranged vertically, and the curvature of the cylindrical wave is precisely controlled by a connecting mechanism and an adjusting mechanism to achieve continuous adjustment of the vertical directionality. Background Art

[0002] Traditional sound reinforcement systems, such as the prior art Chinese patent ZL201921547041.7, disclose a coaxial loudspeaker. In this patent, a woofer voice coil is placed coaxially within a frame, and a tweeter is placed within the woofer voice coil. This patented technology allows the speaker to simultaneously output both bass and treble, without interference between the woofer voice coil and tweeter, thus ensuring high-quality sound.

[0003] However, the aforementioned existing technology is only applicable to the application of spherical waves emitted by point sound sources. The coaxial horns of linear sound sources and cylindrical waves in modern sound reinforcement systems also need to be designed accordingly based on the characteristics of linear sound sources and cylindrical waves.

[0004] The main requirements for modern professional sound reinforcement systems are: 1. High sound pressure levels, achieved through coupling and superposition; 2. Low distortion, achieved through optimized structural design; and 3. Uniform coverage, achieved through good directional control. To meet these requirements, line sources and cylindrical waves offer significant advantages over traditional point sources and spherical waves.

[0005] In theory, a point sound source is a spherical wave, and a line sound source is a cylindrical wave, and their transmission characteristics are essentially different. Figure 1 As shown, the wavefronts generated by the point sound source 2 are concentric spheres, which are called spherical waves. Imagine a spherical sound source in an infinite homogeneous medium. Its surface expands and contracts rapidly, and each point on the surface vibrates with the same phase and amplitude. The waves radiated to the surrounding medium are spherical waves. This type of sound wave is spherically symmetric, that is, the magnitude of the sound pressure is only related to the distance from the center of the sphere. Any shape of sound source, as long as its size is much smaller than the wavelength, can be regarded as a point sound source and radiate spherical waves. For spherical waves, the sound intensity at any distance from the sound source is inversely proportional to the square of the distance, the sound pressure is inversely proportional to the distance, and the phase difference between the sound pressure and the vibration velocity is inversely proportional to the ratio of the radius of the spherical wave to the wavelength.

[0006] like Figure 2As shown, the wavefront generated by the line sound source 4 is a coaxial cylindrical wave, known as a cylindrical wave. A cylindrical wave is a wave with a coaxial cylindrical wavefront. Imagine an infinitely long uniform line sound source in an infinitely uniform medium. The wave it generates is an ideal cylindrical sound wave. In a cylindrical sound wave, the sound pressure amplitude is uniform along the axial direction and inversely proportional to the square root of the distance from the axis in the radial direction. Its radial sound intensity is inversely proportional to the first power of the distance from the axis.

[0007] The above acoustic theory analysis demonstrates that the acoustic properties of a line sound source composed of cylindrical waves are far superior to those of a point sound source composed of traditional spherical surface waves. Specifically, these properties are: 1. Transmission characteristics—twice as efficient. 2. Excellent coupling characteristics, with low distortion caused by interference. 3. Better directivity control (strong vertical directionality). Therefore, converting spherical waves into cylindrical waves has become a major focus for researchers in this field.

[0008] Existing technology, Chinese patent CN201320153532.X, discloses a phase-plug-implanted tweeter horn for sound reinforcement. This technology uses a spindle-shaped phase plug to create a path compensation effect, changing the transmission characteristics of the sound wave from a spherical wave to a cylindrical wave.

[0009] Modern acoustic theory posits the following conditions for the conversion of spherical waves to cylindrical waves: 1. The center-to-center distance between closely spaced independent sound sources must be less than half the wavelength of the upper frequency limit of their operating bandwidth. 2. The multiple independent sound sources must be in-phase wavefronts, with the effective radiation area accounting for at least 80% of the total area. In theory, if either of these two conditions is met, the conversion from spherical waves to cylindrical waves can be achieved.

[0010] Regarding the first condition, existing industry products offer a variety of waveform converter structures. Their basic principle is to achieve equal phase characteristics by adjusting the curvature of the waveguide (sound channel) to align the acoustic paths of each channel. Prior art, including Chinese patent ZL200820207136.X, discloses a high-frequency directivity control converter for sound reinforcement. By setting up several transmission channels with equal acoustic paths, this converter converts spherical waves into cylindrical waves, thereby controlling the directivity of the cylindrical waves.

[0011] The earliest line sound source theory comes from Olson's paper: "A linear sound source is an array of a large number of point sound sources of equal intensity (SPL) and phase, distributed along a straight line, with equal spacing but very small amplitudes." This suggests that an ideal line sound source should consist of an infinite number of closely spaced, continuous, and equally phased vibrating units of equal intensity, with the acoustic wavefront being a cylindrical wave. Among existing industry products, the earliest application of line sound source theory was the sound column. Its primary goal was to achieve vertical control through the close arrangement of multiple units, thereby reducing acoustic reflections from the ceiling and floor, improving sound reinforcement clarity, and enhancing transmission efficiency.

[0012] like Figure 10 As shown in the figure, a mid-range sound column contains four vertically arranged mid-range horns. However, conventional sound columns have obvious technical defects. (1) The upper limit of the effective frequency range is affected by the size of the speaker unit. On the one hand, the distance between adjacent sound sources must be less than or equal to half of the wavelength corresponding to the upper limit of the effective frequency, which requires the speaker unit size to be small, otherwise there will be obvious interference effects, which will deteriorate the sound quality of the sound reinforcement. On the other hand, the use of small-sized units will reduce their power and effective sound radiation area accordingly, which will directly reduce the sound reinforcement efficiency and deteriorate the sound quality in the low-frequency band. Therefore, conventional sound columns, due to their limited effective frequency response range, usually 200 to 4000 Hz, are only used for language and broadcasting sound reinforcement.

[0013] like Figure 11 The non-coaxial two-way column speaker shown in the figure is composed of a row of mid-range horns and a row of tweeter horns arranged adjacent to each other. Although it can improve the effective frequency range, the horizontal off-axis response and directivity cause a discontinuity effect due to the distance difference between the tweeter and mid-range, affecting the sound reinforcement quality and sound field uniformity.

[0014] like Figure 12 The coaxial two-way column speaker shown in the figure has a row of tweeter horns placed in front of a coaxial row of midrange horns. Although the coaxial arrangement partially improves the sound quality, it also has a discontinuity effect due to the shielding and reflection of the midrange sound waves by the tweeter. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to provide a sound column with adjustable vertical directionality, which includes a plurality of coaxial cylindrical wave mid-high frequency speakers arranged vertically, and accurately controls the curvature of the cylindrical wave through a connecting mechanism and an adjusting mechanism to achieve continuous adjustment of the vertical directionality.

[0016] The present invention provides an adjustable vertically directed sound column, comprising a plurality of coaxial cylindrical wave mid-range and tweeter speakers arranged vertically, a speaker connection mechanism, and a sound column direction adjustment mechanism. The speaker comprises a box body with a trapezoidal vertical cross-section and a coaxial cylindrical wave mid-range and tweeter module mounted on a panel of the box body. The coaxial cylindrical wave mid-range and tweeter module comprises a midrange horn having a common axis, a tweeter module, and a midrange phase plate. The tweeter module is embedded in the midrange phase plate, and the midrange phase plate is placed on the midrange horn.

[0017] As an improvement, the tweeter module includes at least one tweeter horn, which includes a tweeter magnet, a tweeter diaphragm, a waveguide horn, and a tweeter phase plug with a common axis. The tweeter diaphragm is connected to the tweeter magnet and converts electrical signals into vibrations and sounds. The waveguide horn is basin-shaped and surrounds the tweeter magnet and the tweeter diaphragm. The tweeter diaphragm is a convex spherical surface, and the tweeter phase plug is a concave spherical surface. The spherical surface of the tweeter phase plug corresponds to the spherical surface of the tweeter diaphragm. The tweeter phase plug is connected to the waveguide horn through a cross-shaped connecting rib, and the edge of the connecting rib corresponds to the surface of the tweeter diaphragm.

[0018] As an improvement, the tweeter module includes 3 tweeter horns.

[0019] As an improvement, on the cross section of the tweeter horn, the difference between the sum of the lengths of arc OA and arc AB on the surface of the tweeter phase plug and the length of arc CD on the inner surface of the waveguide horn is less than one-quarter of the wavelength corresponding to the upper frequency limit adapted by the tweeter horn.

[0020] As an improvement, the midrange phase plate is cross-shaped, consisting of a vertical plate in the vertical direction and a horizontal plate in the horizontal direction. The waveguide horn of the tweeter horn is connected to the vertical plate. The cross section of the vertical plate is V-shaped, and the ridges of the vertical plate correspond to the outer surface of the midrange diaphragm of the midrange horn. The cross section of the horizontal plate is triangular, and the lower surface of the horizontal plate corresponds to the outer surface of the midrange diaphragm of the midrange horn.

[0021] As an improvement, the difference between the sum of the lengths of the vertical plate outer surface arc oa and the waveguide horn outer surface arc ab and the length of the horizontal plate outer surface arc od is less than one-quarter of the wavelength corresponding to the upper frequency limit adapted by the midrange horn.

[0022] As an improvement, the cross plate is triangular in cross section BB, and the difference between the sum of the lengths of the arc line ef on the lower surface and the arc line fg on the upper surface of the cross plate and the length of the arc line hj on the outer surface of the midrange diaphragm is less than one-quarter of the wavelength corresponding to the upper frequency limit adapted by the midrange horn.

[0023] As an improvement, the speaker connection mechanism is a hinge arranged on the outer surface of the speaker, connecting adjacent speakers and allowing the adjacent speakers to deflect relative to each other.

[0024] As an improvement, the sound column direction adjustment mechanism includes an adjustment plate and an adjustment bolt respectively arranged on the back panels of adjacent sound boxes.

[0025] The beneficial effects brought about by the present invention compared with the prior art are: the present invention provides an adjustable vertical pointing sound column, including a plurality of coaxial cylindrical wave mid-high frequency speakers arranged vertically, and accurately controls the curvature of the cylindrical wave through a connecting mechanism and an adjusting mechanism to achieve continuous adjustment of the vertical pointing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1Schematic diagram of a point sound source and a spherical wave.

[0027] Figure 2 Schematic diagram of a line sound source and cylindrical wave.

[0028] Figure 3A 、 Figure 3B Schematic diagram of the structure of a coaxial cylindrical wave mid-high frequency speaker in one embodiment of the present invention.

[0029] Figure 4A Schematic diagram of the structure of the tweeter module in one embodiment of the present invention.

[0030] Figure 4B Schematic diagram of the structure of a tweeter horn in one embodiment of the present invention.

[0031] Figure 5A Schematic diagram of the structure of a midrange phase plate in one embodiment of the present invention.

[0032] Figure 5B Schematic diagram of the connection between the midrange phase plate and the waveguide horn in one embodiment of the present invention.

[0033] Figure 5C Schematic diagram of a mid-high frequency module according to an embodiment of the present invention.

[0034] Figure 5D Schematic diagram of a midrange horn and a midrange phase plate according to an embodiment of the present invention.

[0035] Figure 6 It is a front view schematic diagram of a tweeter horn according to an embodiment of the present invention.

[0036] Figure 7 The figure is a front view of a mid-range horn according to an embodiment of the present invention.

[0037] Figure 8 The beam lines of the midrange horn of the prior art and the present invention are shown.

[0038] Figure 9A and Figure 9B It is a schematic diagram of a speaker connection mechanism and a sound column direction adjustment mechanism in one embodiment of the present invention.

[0039] Figure 9C is a schematic diagram of an embodiment of the present invention.

[0040] Figure 10 It is a schematic diagram of a mid-range sound column in the prior art.

[0041] Figure 11 It is a schematic diagram of a non-coaxial mid-high pitch column speaker in the prior art.

[0042] Figure 12It is a schematic diagram of a coaxial mid-high pitch column sound in the prior art.

[0043] Figure 13A and Figure 13B This is a schematic diagram of the present invention meeting the requirements of different application scenarios by adjusting the directivity. DETAILED DESCRIPTION

[0044] The present invention will be further described below with reference to the accompanying drawings.

[0045] like Figure 1 , a schematic diagram of a point sound source and a spherical wave. As shown in the figure, the wavefront generated by point sound source 2 is a concentric sphere, known as a spherical wave. Imagine a spherical sound source in an infinite homogeneous medium. Its surface rapidly expands and contracts, and each point on the surface vibrates 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 that the magnitude of the sound pressure depends only on the distance from the center of the sphere. A 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 a spherical wave, the sound intensity at any distance from the sound source is inversely proportional to the square of the distance. As shown in the figure, 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 drops to 1 / 4.

[0046] like Figure 2 , a schematic diagram of a line sound source and a cylindrical wave, as shown, shows that the wavefront generated by the line sound source 4 is a coaxial cylindrical wave, which is called a cylindrical wave. A cylindrical wave is a wave whose wavefront is a coaxial cylindrical wave. Imagine that there is an infinitely long uniform line sound source in an infinitely uniform medium. The wave it generates is an ideal cylindrical sound wave. In a cylindrical sound wave, the sound pressure amplitude is uniform 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 figure, when the distance from the sound source increases from R to R2, that is, twice R, the area of ​​the wavefront increases from A to 2A, and the sound intensity drops to 1 / 2.

[0047] Figure 3A 、 Figure 3B The structure diagram of a coaxial cylindrical wave mid-high frequency speaker in one embodiment of the present invention is shown in FIG. Figure 3A is a vertical plane cross-sectional view, Figure 3B is a cross-sectional view of the horizontal plane. Figure 3A 、 Figure 3B As shown, in one embodiment of the present invention, a coaxial cylindrical wave mid-treble speaker 6 includes a cabinet 8 and a coaxial cylindrical wave mid-treble module 10 mounted on a cabinet panel. The coaxial cylindrical wave mid-treble module 10 includes a midrange horn 12 having a common axis Y, a tweeter module 14, and a midrange phase plate 16. The tweeter module 14 is embedded in the midrange phase plate 16, which is positioned on the midrange horn 12. The tweeter module 14 includes three tweeter horns 18.

[0048] Figure 4A This is a schematic diagram of the structure of a tweeter module in one embodiment of the present invention. The tweeter module 14 includes three tweeter horns 18. The tweeter horns 18 comprise a tweeter magnet 20 (not shown because it is obscured by the tweeter diaphragm 22) with a common axis, a tweeter diaphragm 22, a waveguide horn 24, and a tweeter phase plug 26. The waveguide horn 24 is basin-shaped and surrounds the tweeter magnet 20 and tweeter diaphragm 22. The tweeter phase plug 26 covers the center of the tweeter diaphragm 22 and is connected to the waveguide horn 24 via a cross-shaped connecting rib 28.

[0049] Figure 4B This is a schematic diagram of the structure of a tweeter horn according to one embodiment of the present invention. The tweeter horn 18 comprises a tweeter magnet 20, a tweeter diaphragm 22, a waveguide horn 24, and a tweeter phase plug 26, all with a common axis Y1. The tweeter diaphragm 22 is connected to the tweeter magnet 20 and converts electrical signals into vibrations and sound. The waveguide horn 24 is basin-shaped and surrounds the tweeter magnet 20 and the tweeter diaphragm 22. The tweeter diaphragm 22 has a convex spherical surface, while the tweeter phase plug 26 has a concave spherical surface, with the spherical surface of the tweeter phase plug 26 corresponding to the spherical surface of the tweeter diaphragm 22. In a cross-section of the tweeter horn 18, the difference between the sum of the lengths of arcs OA and AB on the surface of the tweeter phase plug 26 and the length of arc CD on the inner surface of the waveguide horn 24 is less than one-quarter of the wavelength corresponding to the upper frequency limit of the tweeter horn. The tweeter phase plug 26 is connected to the waveguide horn 24 via a cross-shaped connecting rib 28, the edge of which corresponds to the surface of the tweeter diaphragm 22.

[0050] Figure 5A The figure below is a schematic diagram of the structure of a midrange phase plate in one embodiment of the present invention. The midrange phase plate 16 is cross-shaped and consists of vertical vertical plates 30 and horizontal horizontal plates 32. The vertical plates 30 have a width of W1, and the horizontal plates 32 have a width of W2. To facilitate connection between the midrange phase plate 16 and the panel of the cabinet 8, the midrange phase plate 16 may include a connecting plate 34 that surrounds the midrange phase plate 16 and connects the ends of the vertical plates 30 and the horizontal plates 32.

[0051] Figure 5B FIG. 1 is a schematic diagram of the connection relationship between the midrange phase plate and the waveguide horn in one embodiment of the present invention. The waveguide horn 24 and the riser 30 of the treble horn can be connected at corresponding holes.

[0052] Figure 5CThe figure is a schematic diagram of a midrange / treble module according to one embodiment of the present invention. The coaxial cylindrical wave midrange / treble module 10 includes a midrange horn 12, a tweeter module 14, and a midrange phase plate 16, all of which share a common axis Y. The tweeter module 14 is embedded in the midrange phase plate 16, which is positioned on the midrange horn 12. The waveguide horn 24 of the tweeter horn is connected to a riser 30. The riser 30 has a V-shaped cross-section, with the ridgeline of the riser 30 aligning with the outer surface of the midrange diaphragm 36 of the midrange horn 12. The lower surface of the crossbar 32 aligns with the outer surface of the midrange diaphragm 36 of the midrange horn 12. The difference between the sum of the lengths of the arc line oa of the riser 30 and the arc line ab of the waveguide horn 24 and the length of the arc line od of the crossbar 32 is less than one-quarter of the wavelength corresponding to the upper frequency limit of the midrange horn. Among them, point o is the intersection of the outer surface of the vertical plate 30 and the axis Y, point a is the end point of the outer surface of the vertical plate 30, point b is the end point of the outer surface of the waveguide horn 24, and point d is the intersection of the intersection line of the horizontal plate 32 and the connecting plate 34 on the cross section.

[0053] Figure 5D This is a schematic diagram of a midrange horn and midrange phase plate according to one embodiment of the present invention. The midrange phase plate 16 is placed on the midrange horn 12. The ridgeline of the vertical plate 30 corresponds to the outer surface of the midrange diaphragm 36 of the midrange horn 12. The horizontal plate 32 has a triangular cross-section, with its lower surface corresponding to the outer surface of the midrange diaphragm 36. The horizontal plate 32 has a triangular shape in the cross-section (BB). The difference between the sum of the lengths of the arc line ef on the lower surface and the arc line fg on the upper surface of the horizontal plate 32 and the length of the arc line hj on the outer surface of the midrange diaphragm 36 is less than one-quarter of the wavelength corresponding to the upper frequency limit of the midrange horn. In the cross-section (BB), point e is the intersection of a vertical line parallel to the axis Y and the lower surface of the horizontal plate 32, point f is the endpoint of one side of the horizontal plate 32, g is the vertex of the horizontal plate 32, point h is the intersection of a vertical line parallel to the axis Y and the outer surface of the midrange diaphragm 26, and point j is the endpoint of the midrange diaphragm.

[0054] In one embodiment of the present invention, the development and design process of a coaxial cylindrical wave mid-high frequency speaker mainly includes the following steps:

[0055] (1) Select the effective frequency response range of the speaker. Usually, to meet the various application requirements of modern sound reinforcement, the effective frequency response range of a two-way speaker system is usually 100Hz to 18KHz (-10dB).

[0056] (2) Select the tweeter / midrange unit. According to the existing industrial standards, the smallest tweeter that can meet the sound reinforcement requirements (sensitivity, power handling, and maximum sound pressure level) is 0.75 inches, with an outer diameter of approximately 31 mm. According to the industrial standards, the smallest midrange unit that can meet the sound reinforcement requirements and f0≈100 Hz is 4 inches, with an outer diameter of approximately 107 mm. Accordingly, using the equal distance method, the tweeter / midrange ratio is selected to be 3:1.

[0057] (3) Tweeter calibration. First, according to the line sound source equivalent condition, the distance LH between two adjacent tweeters should be less than or equal to half of the upper frequency wavelength. Therefore, when the coupling upper limit frequency fup of the tweeter is 18KHz, its sound source distance LH can be calculated according to fup = 18KHz and sound velocity V0 = 343 m / s, and LH ≤ 9.5 mm. In the existing industrial standards, the minimum size tweeter that can meet the sound reinforcement conditions (sensitivity, power handling, maximum sound pressure level) is 0.75 inches, and its outer diameter is about 31 mm. Correspondingly, when the tweeter sound source distance LH is 31 mm, its corresponding coupling upper limit frequency fup = 5532 Hz, which is much smaller than the expected coupling upper limit frequency fup = 18000 Hz. It can be seen from this that the direct tweeter cannot meet the set conditions of fup, so the only way to design the matching "tweeter phase plug + waveguide horn" structure is to use the "sound spacing" equal division method of phase plug + waveguide horn.

[0058] (4) Midrange unit calibration. In the existing industrial standards, the nominal frequency response range of the 0.75-inch tweeter is 1500Hz to 20000Hz. In the actual frequency division application design, in order to ensure its long-term safety, reliability and low distortion, the "retraction octave rule" is usually adopted to shift the lower limit of the operating frequency up by 1 times the frequency. From this, it can be determined that the long-term effective operating frequency range is: 3000Hz to 20000Hz. From this, it can also be deduced that the lower limit of the crossover frequency of the 0.75-inch tweeter is 3000Hz, and the crossover point of the two-way crossover of the speaker is fmin ≥ 3000Hz. According to the line sound source theory, a continuous line sound source can only be formed when the coupling upper limit frequency fup of the midrange unit in the speaker system is ≥ 3000Hz. In the existing industrial standards, the minimum midrange unit that can meet the sound reinforcement conditions and f0 ≈ 100Hz is 4 inches, and its outer diameter is about 107 mm. Correspondingly, when the midrange driver's sound source distance LH is 107 mm, the corresponding upper coupling frequency fup = 1603 Hz. Under direct radiation conditions, fup = 1603 Hz is far less than the required 3000 Hz. Therefore, the phase plate "sound spacing" equalization method must be used to reduce the sound distance and increase fup to meet the line source condition.

[0059] (5) Tweeter phase plug + waveguide horn structure design. Figure 4A As shown, the tweeter horn 18 includes a tweeter magnet 20 (not shown because it is blocked by the tweeter diaphragm 22) with a common axis, a tweeter diaphragm 22, a waveguide horn 24, and a tweeter phase plug 26. The waveguide horn 24 is basin-shaped and surrounds the tweeter magnet 20 and the tweeter diaphragm 22. The tweeter phase plug 26 covers the center of the tweeter diaphragm 22 and is connected to the waveguide horn 24 via a cross-shaped connecting rib 28. Accordingly, as shown in FIG. Figure 6The front view of the tweeter horn shown shows the tweeter horn 18 divided into four identical fan-shaped areas by a cross-shaped connecting rib 28, forming four virtual sound sources S1-S4. The centers of the four virtual sound sources are the virtual sound source points C1-C4. The diameter of the tweeter phase plug 26 is DS, and the outer diameter of the tweeter diaphragm 22 is DZ. Each virtual sound source point C1-C4 is located at the intersection of a circle with a diameter DY and a 45° ray X1-X4 starting from the center of the circle K, where DY = (DS + DZ) / 2. Accordingly, the vertical and horizontal spacing between the virtual sound source points C1-C4 is LH, which is the distance between two adjacent tweeter sound sources.

[0060] According to the specifications of the 0.75-inch tweeter, the outer edge diameter DZ of its tweeter diaphragm is about 19 mm, and the diameter of the selected tweeter phase plug is 8 mm. The diameter DY of the circle where the virtual sound source points C1-C4 are located is 13.5 mm. Correspondingly, the vertical and horizontal spacing LH of the virtual sound source points C1-C4 is 9.5 mm, which can meet the requirement of the tweeter coupling upper limit fup = 18KHz.

[0061] Furthermore, to reduce coupling distortion, the difference between the sum of the lengths of arcs OA and AB on the surface of tweeter phase plug 26 and the length of arc CD on the inner surface of waveguide horn 24 must be less than one-quarter of the wavelength corresponding to the upper frequency limit of the tweeter horn, which is 2.375 mm. Based on these constraints and referring to the specifications of a 0.75" tweeter, the dimensions of the tweeter phase plug and waveguide horn can be determined using CAD software.

[0062] (6) Midrange phase plate structure design. Similarly, the sound spacing equal division method, assisted by CAD software, can be used to determine the structural dimensions of the midrange phase plate. Figure 5A As shown, the midrange phase plate 16 is cross-shaped and consists of a vertical plate 30 and a horizontal plate 32. The width of the vertical plate 30 is W1, and the width of the horizontal plate 32 is W2. For the convenience of design and verification, the width W1 of the vertical plate 30 = the width W2 of the horizontal plate 32.

[0063] like Figure 7The front view of the midrange horn shown shows the midrange horn 12 divided into four identical sector-shaped areas by the cross-shaped midrange phase plate 16, forming four virtual sound sources M1-M4. The centers of the four virtual sound sources are the virtual sound source points N1-N4. The intersection of the vertical plate 30 and the horizontal plate 32 covers the center of the midrange diaphragm 36. The diameter of the inscribed circle around the four intersection points is D1. The outer diameter of the midrange diaphragm 36 is D2. Each virtual sound source point N1-N4 is located at the intersection of a circle with a diameter of D3 and a 45° ray X1-X4 originating from the center P of the circle, where D3 = (D1+D2) / 2. Accordingly, the vertical and horizontal spacing between the virtual sound source points N1-N4 is LM, which is the distance between two adjacent midrange sound sources.

[0064] According to the specifications of the 4-inch midrange unit, the outer edge diameter D2 of the sound diaphragm is approximately 102 mm, and the width W1 of the vertical plate 30 is selected to be equal to the width W2 of the horizontal plate 32 = 38 mm, then D1 is approximately equal to 54 mm, and the diameter D3 of the circle where the virtual sound source points N1-N4 are located is 78 mm. Accordingly, the vertical and horizontal spacing of the virtual sound source points N1-N4 is LM = 55 mm. According to the formula, the corresponding crossover point (midrange coupling upper limit frequency) fup ≈ 3118 Hz, which can meet the requirement that the midrange coupling upper limit fup, that is, the crossover point frequency fmin of the two-way frequency division is ≥ 3000 Hz.

[0065] Furthermore, to reduce coupling distortion, the design of the midrange phase plate 16 must also meet the following requirements: 1) The vertical plate 30 has a V-shaped cross-section, with its ridgeline corresponding to the outer surface of the midrange diaphragm 36 of the midrange horn 12. The lower surface of the horizontal plate 32 corresponds to the outer surface of the midrange diaphragm 36 of the midrange horn 12. The difference between the sum of the lengths of the arc line oa on the outer surface of the vertical plate 30 and the arc line ab on the outer surface of the waveguide horn 24 and the length of the arc line od on the outer surface of the horizontal plate 32 is less than one-quarter of the wavelength corresponding to the upper frequency limit of the midrange horn. 2) The horizontal plate 32 has a triangular cross-section, with its lower surface corresponding to the outer surface of the midrange diaphragm 36 of the midrange horn 12. The horizontal plate 32 has a triangular cross-section at section BB, and the difference between the sum of the lengths of the arc line ef on the lower surface and the arc line fg on the upper surface of the horizontal plate 32 and the length of the arc line hj on the outer surface of the midrange diaphragm 36 is less than one-quarter of the wavelength corresponding to the upper frequency limit of the midrange horn. Among them, the upper limit of the frequency adaptation of the mid-range horn is the crossover point frequency f = 3000Hz, and its corresponding wavelength is 57mm.

[0066] Based on the above constraints, referring to the specifications of a 4-inch midrange unit, and using CAD drawing software to assist in design, the size of the midrange phase plate can be determined.

[0067] (7) The "treble phase plug + horn" is embedded in the midrange phase plate to meet the following requirements: ① Effectively reduce the distance between the treble and midrange, reducing the phase distortion caused by it. ② Avoid the acoustic reflection of the tweeter magnet on the midrange sound waves, laying the foundation for the frequency response and directional beam continuity of the midrange / treble frequency division area. ③ The tweeter units are symmetrically distributed, so that the tweeter coupling sound axis coincides with the midrange and treble sound axis, forming an acoustic coaxial structure, and improving the coupling characteristics of the midrange / treble sound waves.

[0068] (8) Design and debugging of the crossover. Based on the aforementioned calculation conditions, the crossover frequency f=3000Hz was selected. The LRC two-order crossover method was used, and an appropriate crossover circuit was selected. Combined with actual testing, the system crossover was completed. After actual testing, the speaker system met the technical pre-set conditions and achieved line source characteristics.

[0069] (9) Speaker assembly: Assemble the speakers as follows: ① Assemble the tweeter -> Install the midrange phase plate. ② Fasten it to the cabinet simultaneously with the midrange unit.

[0070] The coaxial cylindrical wave mid-high frequency speaker of the present invention has the following technical advantages: (1) Through the design of the tweeter phase plug and the waveguide horn, according to the theoretical principle that "sound waves with equal sound paths can form equal phase waves" and the "equal phase coupling superposition principle", an equal phase wave front can be formed at the horn outlet. (2) The tweeter phase plug and the connecting ribs are used to separate the sound source, and the tweeter diaphragm is divided equally to form four independent virtual sound source points, which reduces the distance between the sound sources and increases the upper limit frequency of coupling. (3) According to the "equal path phase coupling" theory, the design of the mid-frequency phase plate can form an equal phase coupling wave front on the outlet surface. (4) The dividing effect of the cross-shaped mid-range phase plate is used to separate the mid-range diaphragm to form four independent virtual sound source points, which reduces the distance between the sound sources and meets the needs of frequency division. (5) The mid-range phase plate increases the upper limit frequency of coupling of the mid-range horn, so that the mid-frequency sound waves are guided out from both sides of the mid-range phase plate, forming a "sound wave diffraction" effect, making the mid-frequency sound waves continuous and consistent. (6) Intermediate frequency phase plate can effectively "widen" the horizontal pointing angle. Figure 8 The figure shows the beam lines of the midrange horn of the prior art and the present invention. The horizontal axis is frequency, and the vertical axis is directional angle. Line 40 is the beam line of the prior art, that is, the midrange horn without a midrange phase plate, and line 42 is the beam line of the present invention, that is, the midrange horn with a midrange phase plate. Tests show that: 1) At the same frequency, the present invention has a larger directional angle. 2) Within the same directional angle range, Figure 8 As shown, from -45 degrees to +45 degrees, the corresponding frequency Pf90 of the technology of the present invention is higher than the Df90 of the prior art, indicating that the phase plate "broadens" the horizontal direction of the mid-frequency. (7) "Embedding" the tweeter into the mid-frequency phase plate minimizes the distance between the high / mid-frequency sound sources, which can effectively improve the phase coupling characteristics of the high / mid-frequency, reduce phase offset, and reduce phase distortion.

[0071] Figure 9A and Figure 9B It is a schematic diagram of a speaker connection mechanism and a sound column direction adjustment mechanism in one embodiment of the present invention. Figure 9A is a vertical cross-sectional view, Figure 9B It is a rear view. The sound column 44 is composed of two coaxial cylindrical wave mid-high frequency speakers 6 (simplified diagram) arranged vertically. The speaker 6 includes a box body 8 with a trapezoidal vertical section. The speaker connection mechanism 46 is a hinge 48 arranged on the outer surface of the speaker 6, connecting adjacent speakers 6 and making adjacent speakers 6 deflect relative to each other. The hinge 48 can be a profile arranged on the outer surface of the speaker 6 and can be engaged with each other. The sound column direction adjustment mechanism 50 includes an adjustment plate 52 and an adjustment bolt 54 respectively arranged on the back panels of adjacent speakers 6. The head of the adjustment plate 52 cooperates with the slide groove on the back panel of the speaker 6 and can slide left and right in the direction of the arrow. There are multiple positioning grooves on the adjustment plate 52, and the adjustment bolt 54 cooperates with the positioning groove to adjust the direction of the sound column.

[0072] Figure 9C The figure is a schematic diagram of an embodiment of the present invention. A sound column 44 with adjustable vertical directionality includes four vertically arranged coaxial cylindrical wave mid-high frequency speakers 6, a speaker connection mechanism 46, and a sound column directionality adjustment mechanism 50. The speaker 6 includes a cabinet 8 having a trapezoidal vertical cross-section and a coaxial cylindrical wave mid-high frequency module 10 mounted on the cabinet panel. The coaxial cylindrical wave mid-high frequency module 10 includes a midrange horn 12, a tweeter module 14, and a midrange phase plate 16, which have a common axis. The tweeter module 14 is embedded in the midrange phase plate 16, which is then mounted on the midrange horn 12.

[0073] Figure 10 It is a schematic diagram of a mid-range sound column in the prior art. The mid-range sound column 56 includes four vertically arranged mid-range horns 12. However, conventional sound columns have obvious technical defects. (1) The upper limit of the effective frequency range is affected by the size of the speaker unit. On the one hand, the distance between adjacent sound sources must be less than or equal to half of the wavelength corresponding to the upper limit of the effective frequency, which requires the speaker unit size to be small, otherwise there will be obvious interference effects, which will deteriorate the sound quality of the sound reinforcement. On the other hand, the use of small-sized units will reduce their power and effective sound radiation area accordingly, which will directly reduce the sound reinforcement efficiency and deteriorate the sound quality in the low-frequency band. Therefore, conventional sound columns, due to their limited effective frequency response range, usually 200 to 4000 Hz, are only used for language and broadcasting sound reinforcement.

[0074] Figure 11This is a schematic diagram of a non-coaxial mid-treble column speaker in the prior art. Non-coaxial mid-treble column speaker 58 comprises a row of mid-range horns 12 and a row of tweeter horns 18 arranged adjacently. While this solution improves the effective frequency range, the horizontal off-axis response and directivity, caused by the distance difference between the treble and mid-range, creates a discontinuity effect, affecting the sound quality and uniformity of the sound field.

[0075] Figure 12 This is a schematic diagram of a coaxial mid-treble column speaker in the prior art. Coaxial mid-treble column speaker 60 comprises an array of midrange horns 12 and a array of tweeter horns 18, with the tweeter horns 18 mounted on the surface of the midrange horns 12 via mounting plates 62. While the coaxial arrangement of the midrange and tweeter horns partially improves sound quality, it also introduces a discontinuity effect due to the shielding and reflection of midrange sound waves by the tweeter 18 and its mounting plates 62.

[0076] Compared to existing technologies, this invention adopts a modular design. Instead of assembling a single array of midrange horns and a single array of tweeter horns within a single speaker cabinet, the existing design utilizes a vertically arranged sound column composed of multiple coaxial cylindrical wave midrange and tweeter speakers, improving the adaptability of the sound column. On the one hand, the number of speakers used can be adjusted to meet the amplification needs of different spaces. On the other hand, the directivity of the sound column can be adjusted through the speaker connection mechanism and the sound column direction adjustment mechanism to meet the needs of different application scenarios. Figure 13A and Figure 13B This is a schematic diagram of the present invention meeting the requirements of different application scenarios by adjusting the directivity. Figure 13A and Figure 13B It is respectively illustrated that the directivity of the sound column 44 is adjusted by the speaker connection mechanism and the sound column direction adjustment mechanism, which can meet the different application requirements of the flat theater and the stepped theater respectively.

Claims

1. A sound column with adjustable vertical direction, characterized in that: The invention comprises a plurality of coaxial cylindrical wave mid-high frequency speakers arranged vertically, a speaker connection mechanism, and a sound column direction adjustment mechanism. The speaker comprises a box body with a trapezoidal vertical cross-section and a coaxial cylindrical wave mid-high frequency module installed on the box body panel. The coaxial cylindrical wave mid-high frequency module comprises a mid-range horn with a common axis, a tweeter module, and a mid-range phase plate. The tweeter module is embedded in the mid-range phase plate, and the mid-range phase plate is placed on the mid-range horn. The tweeter module comprises at least one tweeter horn, and the tweeter horn comprises a tweeter magnet with a common axis, a tweeter diaphragm, a waveguide horn, and a tweeter phase plug. The tweeter diaphragm is connected to the tweeter magnet and converts electrical signals into vibration and sound. The waveguide horn is basin-shaped and surrounds the tweeter magnet and tweeter diaphragm. The treble diaphragm is a convex spherical surface, the treble phase plug is a concave spherical surface, the spherical surface of the treble phase plug corresponds to the spherical surface of the treble diaphragm, the treble phase plug is connected to the waveguide horn through a cross-shaped connecting rib, and the edge of the connecting rib corresponds to the surface of the tweeter diaphragm. The midrange phase plate is cross-shaped, and the midrange phase plate consists of a vertical plate in the vertical direction and a horizontal plate in the horizontal direction. The waveguide horn of the tweeter horn is connected to the vertical plate. The cross section of the vertical plate is V-shaped, and the ridge line of the vertical plate corresponds to the outer surface of the midrange diaphragm of the midrange horn. The cross section of the horizontal plate is triangular, and the lower surface of the horizontal plate corresponds to the outer surface of the midrange diaphragm of the midrange horn. The sound column direction adjustment mechanism includes an adjustment plate and an adjustment bolt respectively arranged on the back panels of adjacent speaker boxes.

2. The adjustable vertical direction sound amplification column according to claim 1, characterized in that: The tweeter module includes three tweeter horns.

3. The adjustable vertical direction sound amplification column according to claim 1, characterized in that: The speaker connection mechanism is a hinge arranged on the outer surface of the speaker, connecting adjacent speakers and enabling the adjacent speakers to deflect relative to each other.

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