Sound amplification system capable of controlling sound field range

Abstract

The utility model provides a sound amplification system capable of controlling a sound field range. The sound amplification system comprises more than two sound amplification units and a pointing mechanism used for connecting and adjusting the sound amplification units. Wherein the sound amplification unit comprises a sound gathering cover and a linear sound source column loudspeaker arranged in the sound gathering cover, so that a sound field control system is formed, the diffusion range of sound waves is effectively controlled, and sound pollution and sound interference caused by sound leakage and sound dyeing can be effectively reduced. The pointing mechanism can adjust the sound field range according to the needs of the application scene.

Description

Technical Field

[0001] This utility model relates to a sound amplification device, and more particularly to a sound amplification system with controllable sound field range. This sound amplification system includes two or more amplification units and a directional mechanism for connecting and adjusting the amplification units. Each amplification unit includes a sound-focusing enclosure and a line source sound column disposed within the sound-focusing enclosure, constituting a sound field control system. This system effectively controls the diffusion range of sound waves, effectively reducing sound leakage, sound coloration leading to sound pollution, and sound interference. The directional mechanism can adjust the sound field range according to the needs of the application scenario. Background Technology

[0002] Theoretically, point sound sources produce spherical waves, while line sound sources produce cylindrical waves, and their transmission characteristics are fundamentally different. For example... Figure 1 As shown, the wavefront generated by point sound source 2 is a concentric sphere, called a spherical wave. Imagine a spherical sound source in an infinitely uniform medium, whose surface rapidly expands and contracts, with each point on the surface vibrating in phase and amplitude. The wave radiated into the surrounding medium is a spherical wave. This 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 source, radiating spherical waves. For spherical waves, the sound intensity at any distance from the 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.

[0003] like Figure 2 As shown, the wavefront generated by line sound source 4 is a coaxial cylindrical wave, called 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.

[0004] As can be seen from the above acoustic theory analysis, the acoustic characteristics of a line sound source composed of cylindrical waves are far superior to those of a traditional point sound source composed of spherical waves. Specifically, this is manifested in: 1. Transmission characteristics: twice the efficiency. 2. Good coupling characteristics: low distortion caused by interference. 3. Better directivity control (strong directivity in the vertical direction). Therefore, how to convert spherical waves into cylindrical waves has become the main research focus of researchers in this field.

[0005] Prior art, Chinese patent application CN202210427881.X, discloses an adjustable vertically directional loudspeaker column. This technology uses a series of coaxial cylindrical mid-to-high frequency speakers to form a line sound source loudspeaker column.

[0006] In practical applications of public address systems, there are many situations where precise and controllable amplification range is required to reduce interference between sound sources. For example, the zoned sound control needs of museums and exhibition halls, or square dancing venues, often result in noise pollution and disturbance disputes due to uncontrollable sound field range. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a sound amplification system with controllable sound field range. This sound amplification system consists of two or more amplification units and a directional mechanism for connecting and adjusting the amplification units. The amplification units, through the combination of a sound-focusing enclosure and a line sound source column set inside the sound-focusing enclosure, perform three-dimensional control of sound wave diffusion, thereby achieving precise control of the sound field range.

[0008] This invention provides a sound amplification system with controllable sound field range, including two or more amplification units and a pointing mechanism for connecting and adjusting the amplification units.

[0009] As an improvement, the amplification unit includes a sound-focusing enclosure and a line sound source column disposed within the sound-focusing enclosure.

[0010] As an improvement, the line sound source columns include mid-to-high frequency sound columns and low frequency sound columns arranged back to back, with the low frequency sound columns facing the opening of the sound-gathering enclosure.

[0011] As an improvement, the cross-section of the sound-focusing enclosure is a first-order parabola. The acoustic center point of the mid-to-high frequency sound column is at the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The first-order parabola extends along the axis of the line sound source sound column to form a first-order parabolic surface, which constitutes the inner surface of the sound-focusing enclosure.

[0012] Furthermore, the cross-section of the sound-focusing enclosure presents a second-order combined parabola. The acoustic center of the mid-to-high frequency sound column is at the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The acoustic center of the low-frequency sound column is at the focus of the second-order parabola. The opening width of the second-order parabola is equal to the wavelength corresponding to the lower limit of the controllable frequency of the low-frequency sound column. The first-order parabola and the second-order parabola intersect at the intersection point. The second-order combined parabola is composed of the first-order parabola before the intersection point and the second-order parabola after the intersection point. The second-order combined parabola extends along the axis of the line sound source sound column to form a second-order combined parabolic surface. The second-order combined parabolic surface constitutes the inner surface of the sound-focusing enclosure.

[0013] As an improvement, the pointing mechanism is an I-shaped connecting mechanism.

[0014] The beneficial effects of this utility model compared with the prior art are as follows: (1) By using a linear sound source column, the sound wave diffusion control along the axis of the linear sound source column is realized. As the length of the column axis increases, the lower limit of the controllable frequency will decrease. (2) By using the sound focusing effect of the sound focusing cover, the sound wave is controlled in the direction of the opening of the sound focusing cover. The diffusion control of mid-to-high frequency sound waves is realized through the first-order parabolic surface, and the diffusion control of low frequency sound waves is realized through the second-order parabolic surface. (3) By using the sound reflection effect of the sound focusing cover, the diffusion control of sound waves in the direction of the axis of the second-order combined parabola is realized. Finally, the sound pressure difference between the inner and outer sound fields of the sound focusing cover can be ≥25dB. (4) The pointing mechanism can be adjusted according to the needs of the application scenario. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a point sound source and a spherical wave.

[0016] Figure 2 This is a schematic diagram of a line sound source and a cylindrical wave.

[0017] Figure 3A and Figure 3B This is a schematic diagram of the linear sound source column structure in one embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the cross-sectional structure of the sound amplification unit in one embodiment of the present invention.

[0019] Figure 5 This is a test curve of the sound pressure field inside and outside the sound-concentrating cover according to an embodiment of this utility model.

[0020] Figure 6A , 6B This is a schematic diagram of the pointing mechanism in one embodiment of the present invention.

[0021] Figure 7A , 7B This is a schematic diagram illustrating the control of the sound field range via a pointing mechanism in one embodiment of the present invention.

[0022] Figure 8A , 8B This is a schematic diagram illustrating the control of the sound field range via a pointing mechanism in one embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] 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.

[0025] 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.

[0026] like Figure 3A and Figure 3B A schematic diagram of a linear sound source column structure, in which... Figure 3A It is a side view. Figure 3B This is a front view. In one embodiment of this utility model, a line source sound column 6 includes a mid-to-high frequency sound column 8 and a low-frequency sound column 10 arranged back-to-back, with the low-frequency sound column 10 facing the opening of the sound-gathering enclosure (not shown). The mid-to-high frequency sound column 8 consists of a row of six coaxial mid-to-high frequency horns 12, and the low-frequency sound column 10 consists of a row of four low-frequency horns 14. The axis 16 of the mid-to-high frequency horns 12 and the axis 18 of the low-frequency horns 14 are parallel to each other and are in the same plane as the axis 20 of the line source sound column 6, the mid-to-high frequency sound column 8, and the low-frequency sound column 10.

[0027] Figure 4 This is a cross-sectional structural diagram of the sound amplification unit in one embodiment of the present invention. The cross-section cuts across the axis of the length of the sound amplification unit 22, which is also the axis of the line sound source column. Therefore, the diagram shows a coaxial mid-high frequency horn 12 and a low-frequency horn 14, arranged back-to-back, with the low-frequency horn 14 facing the opening of the sound-focusing enclosure 24. The axis 16 of the mid-high frequency horn 12 and the axis 18 of the low-frequency horn 14 are parallel to each other; therefore, the cross-sectional view shows that axes 16 and 18 are collinear.

[0028] Figure 4 The diagram further illustrates the design of the second-order combined parabolic surface on the inner surface of the acoustic enclosure 24. In the cross-sectional view, the acoustic enclosure 24 is thin-shell shaped, and its cross-section resembles a second-order combined parabola. The mid-to-high frequency sound column, i.e., the acoustic center point F1 of the mid-to-high frequency horn 12, is at the focus of the first-order parabola P1. The opening width L1 of the first-order parabola P1 is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The low-frequency sound column, i.e., the acoustic center F2 of the low-frequency horn 14, is at the focus of the second-order parabola P2. The opening width L2 of the second-order parabola P2 is equal to the wavelength corresponding to the lower limit of the controllable frequency of the low-frequency sound column. The first-order parabola P1 and the second-order parabola P2 intersect at point C. The second-order combined parabola is formed by the combination of the first-order parabola P1 before point C (i.e., to the left of point C in the figure) and the second-order parabola P2 after point C (i.e., to the right of point C in the figure). The second-order combined parabola extends along the axis of the sound source column to form a second-order combined parabolic surface. The second-order combined parabolic surface forms the inner surface of the sound-gathering cover.

[0029] Correspondingly, if no second-order parabola is set, the cross-section of the sound-concentrating enclosure will be a first-order parabola. The acoustic center point of the mid-to-high frequency sound column is the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The first-order parabola extends along the axis of the line sound source sound column to form a first-order parabolic surface, which constitutes the inner surface of the sound-concentrating enclosure.

[0030] The design steps of the speaker unit of this utility model mainly include:

[0031] (1) Determine the structure and dimensions of the sound column. Based on the requirements of the amplification technical indicators under actual application conditions, select low, medium and high frequency horns, set the crossover frequency, and determine the dimensions of the sound column and the frequency response range of the controllable sound field according to the specifications of the horns.

[0032] (2) Calculate the crossover frequency. According to the line source theory, the acoustic center distance between two adjacent horns should be less than or equal to half the wavelength corresponding to the upper limit of the coupling frequency. Considering that the acoustic center distance between two adjacent horns is approximately equal to the diameter of the horn, the crossover frequency can be determined according to the specifications of the selected horn. For example, the crossover point for low and mid frequencies can be calculated based on the diameter of the low-frequency horn, and the crossover point for mid and high frequencies can be calculated based on the diameter of the mid-frequency horn.

[0033] (3) Determine the acoustic centers of the mid-to-high frequency horn and the low-frequency horn. Theoretically, the acoustic center of the horn is located at the center of the voice coil. The mid-to-high frequency horn uses a coaxial design, and through electronic delay compensation, its coupled acoustic center is located at the center of the mid-frequency and high-frequency horn centers. The acoustic center of the low-frequency horn is located at the center of the low-frequency horn voice coil.

[0034] (4) Determine the second-order combined parabolic surface of the acoustic shield. According to acoustic theory, the size of the baffle is approximately equal to the wavelength of the controllable frequency. Therefore, it can be deduced that the opening width L1 of the first-order parabola is equal to the wavelength corresponding to the crossover frequency of the low-frequency and mid-frequency ranges. In addition, the acoustic center F1 of the mid-high frequency horn is at the focus of the first-order parabola P1. Thus, the shape of the first-order parabola P1 corresponding to the mid-high frequency horn can be determined. Similarly, the opening width L2 of the second-order parabola P2 is equal to the wavelength corresponding to the lower limit of the controllable frequency of the low-frequency sound column. Furthermore, the acoustic center F2 of the low-frequency horn is at the focus of the second-order parabola P2. Thus, the shape of the second-order parabola P2 corresponding to the low-frequency horn can be determined. Subsequently, the first-order parabola P1 and the second-order parabola P2 intersect at point C. The second-order combined parabola is formed by the combination of the first-order parabola P1 before point C (i.e., to the left of point C in the figure) and the second-order parabola P2 after point C (i.e., to the right of point C in the figure). The second-order combined parabola extends along the axis of the sound source column to form a second-order combined parabolic surface, which constitutes the inner surface of the sound-gathering cover.

[0035] Correspondingly, if no second-order parabola is set, the cross-section of the sound-concentrating enclosure will be a first-order parabola. The acoustic center point of the mid-to-high frequency sound column is the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The first-order parabola extends along the axis of the line sound source sound column to form a first-order parabolic surface, which constitutes the inner surface of the sound-concentrating enclosure.

[0036] (5) Combined Focusing. In actual assembly, actual focusing tests must be performed to ensure that the acoustic center F1 of the mid-to-high frequency horn is at the focus of the first-order parabola P1, and the acoustic center F2 of the low-frequency horn is at the focus of the second-order parabola P2. Accordingly, with the acoustic enclosure specifications fixed, the positions of the mid-to-high frequency horn and the low-frequency horn can be finely adjusted to meet the focusing requirements.

[0037] (6) Actual measurement confirmation. Once the actual measurement of the sound pressure difference inside and outside the sound-concentrating cover reaches the design target, the design scheme can be confirmed, mold opening can be carried out, and mass production can begin.

[0038] (7) Assembly and application. Depending on the application requirements, two or more amplifier units can be connected by a pointing mechanism and the sound field range can be adjusted by hinges.

[0039] Figure 5The figure shows the sound pressure test curves of the sound field inside and outside the sound-focusing enclosure according to an embodiment of the present invention. In the figure, curve A is the sound pressure test curve of the sound field inside the sound-focusing enclosure, and curve B is the sound pressure test curve of the sound field outside the sound-focusing enclosure. The test curves show that (1) the sound pressure inside the sound-focusing enclosure is generally greater than the sound pressure outside the sound-focusing enclosure, indicating that the sound-focusing enclosure has the function of reducing sound leakage. (2) In a specific frequency band, such as the 5K to 10K Hz band, the sound pressure inside the sound-focusing enclosure is about 30dB greater than the sound pressure outside the sound-focusing enclosure, indicating that the sound-focusing enclosure has a stronger ability to reduce sound leakage in this frequency band.

[0040] Figure 6A , 6B This is a schematic diagram of a pointing mechanism in one embodiment of the present invention, wherein... Figure 6A , 6B These refer to the top and front views of the mechanism. Figure 6A In the middle, the pointing mechanism 26 is an I-shaped connecting mechanism, including two slat-shaped connecting plates 28 and a fixing plate 30 connected to the connecting plates. The connecting plates 28 are used to connect with the opening of the sound-concentrating cover (not shown), and the two ends of the fixing plate 30 are connected to the middle of the connecting plates 28. Figure 6B In the middle, the fixing plate 30 is shaped like a "Z", and the central space of the "Z" shape of the fixing plate 30 is used to accommodate the sound-gathering cover (not shown).

[0041] Figure 7A , 7B This is a schematic diagram illustrating the control of the sound field range via a pointing mechanism in one embodiment of the present invention. Figure 7A As shown, a sound amplification system 32 with controllable sound field range includes three amplification units 22 and directing mechanisms 26 for connecting and adjusting the amplification units. The directing mechanisms 26 are connected by hinges 34. Figure 7B As shown, the three amplification units 22 are deflected at a certain angle X by the hinge 34, thereby expanding the controllable sound field range.

[0042] Figure 8A , 8B This is a schematic diagram illustrating the control of the sound field range via a pointing mechanism in one embodiment of the present invention. Figure 8A As shown, a sound amplification system 32 with controllable sound field range includes three amplification units 22 and directing mechanisms 26 for connecting and adjusting the amplification units. The directing mechanisms 26 are connected by hinges 34. Figure 8B As shown, the three amplification units 22 are deflected at a certain angle X by the hinge 34, thereby expanding the controllable sound field range.

Claims

1. A sound amplification system with controllable sound field range, characterized in that... It includes two or more amplifier units and a pointing mechanism for connecting and adjusting the amplifier units.

2. The sound reinforcement system with controllable sound field range according to claim 1, characterized in that... The amplification unit includes a sound-focusing enclosure and a line sound source column disposed inside the sound-focusing enclosure.

3. The sound amplification system with controllable sound field range according to claim 2, characterized in that... The linear sound source columns include mid-to-high frequency sound columns and low frequency sound columns arranged back to back, with the low frequency sound columns facing the opening of the sound-gathering cover.

4. A sound reinforcement system with controllable sound field range according to claim 3, characterized in that... The cross-section of the sound-gathering cover is a first-order parabola. The acoustic center point of the mid-to-high frequency sound column is the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The first-order parabola extends along the axis of the line sound source sound column to form a first-order parabolic surface. The first-order parabolic surface forms the inner surface of the sound-gathering cover.

5. A sound reinforcement system with controllable sound field range according to claim 3, characterized in that... The cross-section of the sound-gathering enclosure presents a second-order combined parabola. The acoustic center of the mid-to-high frequency sound column is at the focus of the first-order parabola. The opening width of the first-order parabola is equal to the wavelength corresponding to the mid-to-low frequency crossover frequency. The acoustic center of the low-frequency sound column is at the focus of the second-order parabola. The opening width of the second-order parabola is equal to the wavelength corresponding to the lower limit of the controllable frequency of the low-frequency sound column. The first-order parabola and the second-order parabola intersect at the intersection point. The second-order combined parabola is composed of the first-order parabola before the intersection point and the second-order parabola after the intersection point. The second-order combined parabola extends along the axis of the line sound source sound column to form a second-order combined parabolic surface. The second-order combined parabolic surface constitutes the inner surface of the sound-gathering enclosure.

6. A sound amplification system with controllable sound field range according to claim 1, characterized in that... The pointing mechanism is an I-shaped connecting mechanism.

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