A loudspeaker system

Abstract

This application provides a loudspeaker system to enhance the directivity of mid-to-low frequency sound waves radiated by a speaker subsystem, and to utilize the directivity of the speaker subsystem to prevent reflected sound waves from entering the pickup subsystem and causing interference in the acoustic environment. This allows for a reduction in the lower limit of the pickup frequency of the pickup subsystem, thereby improving the sound amplification gain of the loudspeaker system. The loudspeaker system includes a pickup subsystem and a speaker subsystem. The speaker subsystem includes at least two linearly arranged speaker units. The length of the speaker subsystem along the linear arrangement direction is not less than half the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem. The distance between any two adjacent speaker units is not less than a preset distance.

Description

Technical Field

[0001] This application relates to the field of public address technology, and more particularly to a public address system. Background Technology

[0002] A sound reinforcement system is a system that picks up sound signals, converts them into electrical signals, and then converts those electrical signals back into sound signals through a loudspeaker. Generally, a sound reinforcement system consists of two parts: a pickup system (e.g., a microphone) and a speaker subsystem (e.g., a loudspeaker). To ensure sufficient sound reinforcement gain (i.e., adequate loudness) and sound reinforcement quality (i.e., sufficient clarity), handheld or wearable microphones are commonly used. Furthermore, to increase the proportion of direct sound entering the microphone, it is advisable to place the microphone very close to the sound source.

[0003] Currently, due to reasons such as freeing up hands and facilitating maintenance, non-contact sound reinforcement systems, especially non-contact microphone systems, are becoming mainstream. However, at the same time, because the distance between the microphone and the sound source is relatively far, the sound pressure level of the direct sound entering the microphone system decreases significantly. Furthermore, as more environmental noise, reflected sound, and reverberation enter the microphone system, the proportion of direct sound entering the system also decreases, causing a sharp decline in sound reinforcement quality. Simultaneously, the positive feedback in the entire microphone-reinforcement loop further induces howling, necessitating a reduction in sound reinforcement gain. Clearly, non-contact sound reinforcement systems suffer from low sound reinforcement gain and poor sound reinforcement quality.

[0004] Although microphone arrays are sometimes used in sound reinforcement systems to enhance sound reinforcement gain by utilizing their out-of-beam suppression, their actual out-of-beam suppression capability is less than expected due to the acoustic environment in which they are located (e.g., reflected sound waves and microphone phase). This is especially true for low- and mid-frequency sound waves, where suppression is particularly inadequate. This results in low- and mid-frequency sounds entering the microphone array after reflection or diffraction. Simultaneously, the number of high-frequency beamside lobes and peak gain are also significant. Therefore, in sound reinforcement systems including microphone arrays, the proportion of direct sound entering the microphone array decreases because of its difficulty in suppressing low- and mid-frequency sound waves; furthermore, the significant high-frequency beamside lobes lead to insufficient sound quality emitted by the speaker subsystem after amplification. Despite numerous improvements to feedback suppression algorithms to suppress sound waves entering the microphone and avoid feedback, the problem of insufficient sound reinforcement gain persists in sound reinforcement systems. Summary of the Invention

[0005] This application provides a loudspeaker system to enhance the directivity of the mid-to-low frequency sound waves radiated by the loudspeaker subsystem, and to use the directivity of the loudspeaker subsystem to prevent reflected sound waves in the acoustic environment from entering the pickup subsystem and causing interference, so that the lower limit of the pickup frequency of the pickup subsystem can be lowered, thereby improving the sound amplification gain of the loudspeaker system.

[0006] In a first aspect, embodiments of this application provide a loudspeaker system, including a pickup subsystem and a speaker subsystem. The speaker subsystem includes at least two speaker units arranged linearly. The length of the speaker subsystem along the linear arrangement direction is not less than 1 / 2 of the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem. The distance between any two adjacent speaker units is not less than a preset distance.

[0007] In the loudspeaker system provided in this application embodiment, by increasing the length of multiple linearly arranged speaker units at intervals to a length not less than the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem, the directivity of the low-frequency sound waves output by the speaker subsystem is effectively enhanced. This allows listeners to receive more uniform and consistent low-frequency sound waves (sound) through the speaker subsystem, thereby improving their auditory experience. Simultaneously, this application embodiment avoids the current problem of suppressing low-frequency sound waves entering the pickup subsystem to prevent feedback caused by the speaker subsystem's radiated low-frequency sound waves. This suppression prevents the loudspeaker system from amplifying the low-frequency sound waves emitted by the sound source, resulting in poor sound quality. Therefore, the lower limit of the pickup frequency of the pickup subsystem is no longer limited by the omnidirectionality of the low-frequency sound waves, allowing the lower limit of the pickup frequency to be further lowered, increasing the frequency range of the pickup subsystem's sound pickup (direct sound).

[0008] In one possible implementation, the preset distance is the distance between the two farthest points on any of the speaker units along the arrangement direction of the speaker units.

[0009] In one possible implementation, the preset distance is half the wavelength of the sound wave corresponding to the preset frequency threshold.

[0010] In one possible implementation, the deviation distance between the centers of two adjacent speaker units is no greater than 1 / 10 of the wavelength of the sound wave corresponding to a preset frequency threshold.

[0011] In one possible implementation, the pickup subsystem includes a microphone and an acoustic load plate attached to the back of the microphone; wherein,

[0012] The thickness of the acoustic load plate is no more than 1 cm; the horizontal distance between the center of the microphone and the center of the acoustic load plate is no more than 1 cm.

[0013] In one possible implementation, the microphone is an array microphone, in which the straight-line distance between any microphone unit in the array microphone and any edge of the acoustic load plate is greater than the distance between any two adjacent microphone units.

[0014] In one possible implementation, the acoustic load plate is made of a non-metallic material.

[0015] In one possible implementation, the loudspeaker system further includes a high-frequency loudspeaker subsystem; wherein the pickup subsystem is used to collect the direct sound emitted by the sound source, the high-frequency loudspeaker subsystem is used to process a first electrical signal corresponding to a sound wave of a first frequency, the loudspeaker subsystem is used to process a second electrical signal corresponding to a sound wave of a second frequency, the first electrical signal and the second electrical signal are obtained by a frequency cutter, the first frequency is greater than a preset frequency threshold, and the second frequency is less than or equal to the preset frequency threshold.

[0016] In one possible implementation, the speaker subsystem, the high-frequency amplification subsystem, and the pickup subsystem are all disposed above the amplification space; wherein, the distance between the speaker units in the speaker subsystem and the sound source increases along the arrangement direction, the distance between the pickup subsystem and the sound source is less than the distance between the speaker subsystem and the sound source, and the distance between the pickup subsystem and the target audience is greater than the distance between the speaker subsystem and the target audience.

[0017] In one possible implementation, a plurality of the pickup subsystems are spaced apart above the amplification space, and the plurality of pickup subsystems are distributed along a direction parallel to the long side of the amplification space; wherein, each amplification group to which the pickup subsystem belongs includes two speaker subsystems, and the speaker subsystems in the amplification group are located in opposite side areas of the amplification space. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a current public address system setup.

[0019] Figure 2 An aerial view of the coverage area of ​​the sound waves radiated by a current loudspeaker system in a loudspeaker space;

[0020] Figure 3A A schematic diagram showing the distribution of speaker units in a speaker subsystem provided in an embodiment of this application;

[0021] Figure 3B A schematic diagram showing the distribution of speaker units in a speaker subsystem provided in an embodiment of this application;

[0022] Figure 4 This application provides a schematic diagram of the deviation distance between any two adjacent speaker units in a speaker subsystem.

[0023] Figure 5 A schematic diagram of a sound pickup subsystem for suppressing reflected sound waves, provided in an embodiment of this application;

[0024] Figure 6 A schematic diagram illustrating the relative positional relationship between the acoustic load board and the array microphone in a pickup subsystem provided in this application embodiment;

[0025] Figure 7 A schematic diagram of the shape of an acoustic load plate in a pickup subsystem provided in this application embodiment;

[0026] Figure 8 A schematic diagram of the shape of an acoustic load plate in a pickup subsystem provided in this application embodiment;

[0027] Figure 9 A schematic diagram of the shape of an acoustic load plate in a pickup subsystem provided in this application embodiment;

[0028] Figure 10 This application provides a schematic diagram illustrating the distribution of a loudspeaker system within a loudspeaker space, as shown in the embodiments of the present application.

[0029] Figure 11 This application provides a schematic diagram illustrating the distribution of a loudspeaker system within a loudspeaker space, as shown in the embodiments of the present application.

[0030] Figure 12 This is a schematic diagram of a regional sound reinforcement system provided in an embodiment of this application. Detailed Implementation

[0031] To address the problem of insufficient sound reinforcement gain in current sound reinforcement systems, this application provides a speaker array comprising multiple linearly arranged speaker units spaced at a distance not less than a preset distance. By spaced multiple speaker units, the low-frequency sound wave radiation range is reduced, and the directivity of low-frequency sound waves is increased. This improves the sound reinforcement gain of the sound reinforcement system containing the speaker array, thereby effectively preventing feedback issues in sound reinforcement systems in loudspeaker spaces (such as studios).

[0032] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of this application, rather than limitations on the technical solution of this application. Unless otherwise specified, the embodiments and technical features in the embodiments can be combined with each other.

[0033] To better understand the above technical solutions, the technical terms involved in the embodiments of this application will be explained below:

[0034] Sound: Sound is produced by the vibration of objects; the object emitting sound is called the sound source. The number of vibrations an object makes in one second is the frequency of the sound, measured in Hertz (Hz). The sound source of a sound reinforcement system is the diaphragm of a tweeter or woofer, which converts the electrical signal from the audio power amplifier into sound through diaphragm vibration.

[0035] Sound pressure: When sound is transmitted, the sound waves propagate and disturb the medium, and the resulting pressure change within the medium is called sound pressure, measured in Pascals (Pa). The higher the sound pressure, the louder the sound.

[0036] Sound pressure level (SPL) is the commonly used logarithm of the ratio of sound pressure (P) to the fundamental sound pressure level (P0), expressed in dB. SPL is used to characterize the magnitude of sound pressure.

[0037] The rules governing the sound pressure level of a speaker and the sound it emits: (1) The sound pressure level of a speaker decreases with increasing distance, with the rule being that doubling the distance results in a 6dB decrease in sound pressure level. (2) When the power of each speaker is the same, doubling the number of speakers increases the sound pressure level by 6dB. (3) Doubling the power of a speaker increases the sound pressure level by 3dB. (4) Doubling the distance between a point source and a speaker decreases the sound pressure level by 6dB. (5) Doubling the distance between a linear source and a speaker decreases the sound pressure level by 3dB.

[0038] Direct sound refers to sound that travels directly from its source to the receiver in a straight line without any reflection.

[0039] Reverberation: The phenomenon where sound continues to be emitted after a sound source in a room has stopped emitting sound, due to multiple reflections or scatterings within the room. It reflects the decay of sound energy within the room, which is related to sound absorption, reflection, and scattering within the room.

[0040] Sound wave reflection: refers to the reflection of sound waves when they encounter changes in the density of a medium during propagation. The reflection of sound waves propagating in indoor air depends on the properties of its surface.

[0041] Sound wave diffraction: Diffraction occurs when the width of a slit, aperture, or obstacle is similar to or smaller than the wavelength. The longer the wavelength of the sound wave, the more pronounced the diffraction phenomenon; conversely, the higher the frequency of the sound wave and the shorter the wavelength, the less obvious the diffraction phenomenon, and the propagation direction tends to be straight. Sound waves propagate spherically in a free sound field, and the sound pressure level follows the inverse square law of distance.

[0042] Transmission gain: refers to the difference in dB between the average sound pressure level measured at each specified audience position and the sound pressure level at the microphone when the sound reinforcement system reaches its maximum usable gain (critical gain minus 6dB gain margin).

[0043] To improve the sound reinforcement gain and avoid feedback, the pickup subsystem is currently suspended from the ceiling of the sound reinforcement space (e.g., the ceiling), while the speaker subsystem is vertically positioned near the sound source, with the speaker facing the side of the sound reinforcement space towards the audience. Please refer to [reference needed]. Figure 1Compared to installing the amplification subsystem next to the sound source (e.g., beside the speaker), this effectively reduces early reflections from the ground and ceiling, increasing amplification gain. However, because sound waves have a characteristic where directivity decreases with decreasing frequency, in situations such as... Figure 1 When the sound reinforcement system is set up as shown, the radiation range of the mid- and low-frequency sound waves (i.e., mid- and low-frequency sound waves) from the speaker subsystem is actually very large, especially in the horizontal direction. Figure 2 This is a bird's-eye view of the radiation range of high-frequency and mid-to-low-frequency sound waves within the sound reinforcement space provided in the embodiments of this application, such as... Figure 2 As shown, the large coverage area means that the direct sound area corresponding to mid-to-low frequency sound waves includes the microphone, making it easy for sound to enter the microphone, thus causing feedback and low amplification gain. If the output of low-frequency sound waves in the amplification system is reduced, then low sound quality is likely to occur.

[0044] To address the aforementioned technical problems, embodiments of this application provide a loudspeaker system, which includes a pickup subsystem and a speaker subsystem. The speaker subsystem includes at least two speaker units arranged linearly. Furthermore, the length of the speaker subsystem along the linear arrangement direction is not less than 1 / 2 of the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem.

[0045] The distance between any two adjacent speaker units shall not be less than a preset distance.

[0046] Figure 3A , Figure 3B This is a schematic diagram showing the distribution of speaker units in a speaker subsystem provided in an embodiment of this application. Figures 3A-3B As shown, the distance between any two adjacent speaker units can be equal, unequal, or not all equal. The specific distance can be determined based on the distribution of the audience seating.

[0047] Continue to refer to Figure 3A and Figure 3B The number of loudspeakers included in each speaker unit may be equal or unequal, for example, one or two. Preferably, the number of speaker units is four.

[0048] This application provides two implementation methods for determining the above-mentioned preset distance:

[0049] (I) The preset distance is the two points furthest apart on the edge of the speaker units along the arrangement direction. The side of the speaker unit facing the audience (speaker surface) can be arbitrary, such as circular or polygonal. When the side of the speaker unit facing the audience is circular, the preset unit is the diameter of that circle. When the side of the speaker unit facing the audience is rectangular, and the longer side of the rectangle is in the same direction as the arrangement, see [reference needed]. Figures 3A-3B The preset distance is the length of the longer side of the rectangle.

[0050] (ii) The preset distance is half the wavelength of the sound wave corresponding to the preset frequency threshold. This preset frequency threshold is actually the threshold for distinguishing between high-frequency and mid-to-low-frequency sound waves; that is, sound waves with frequencies less than or equal to the preset frequency threshold are mid-to-low-frequency sound waves, while sound waves with frequencies greater than the preset frequency threshold are high-frequency sound waves. Specifically, the preset frequency threshold can be, for example, 1000Hz or 2000Hz. When the preset frequency threshold is 1000Hz, according to c = λ × f, and the propagation medium is air, half the wavelength of the sound wave is approximately 17cm. Therefore, the preset distance can be 17cm or 18cm.

[0051] Furthermore, the speaker subunit provided in this embodiment is positioned above the audience, so that the sound waves emitted by the speaker subsystem form "cylindrical waves," significantly increasing the proportion of direct sound from the speaker subsystem in the sound waves received by the audience. In addition, the center of the linearly arranged speaker subsystem, i.e., the center of the linear array, is positioned above the center of the audience seating distribution, or slightly offset away from the sound source. The specific offset distance can be set according to the effective distance that the direct sound from the sound source can reach in the audience seating area.

[0052] Furthermore, the deviation distance between the centers of two adjacent speaker units is no greater than 1 / 10 of the wavelength of the sound wave corresponding to the preset frequency threshold. This deviation distance can be uniformly set to 1 cm. The deviation distance is the distance between two straight lines passing through the centers of the two speaker units and parallel to the direction in which the speaker units are arranged. Still considering the speaker unit as a cuboid and the side facing the listener as a rectangle, the deviation distance De is as follows: Figure 4 As shown.

[0053] Furthermore, the pickup subsystem in the aforementioned loudspeaker system includes a microphone and an acoustic load plate attached to the back of the microphone. Please refer to [reference needed]. Figure 5 , Figure 5 The area within the dashed box represents the sound waves suppressed by the back of the acoustic load plate. It can be seen that this acoustic load plate can suppress reflections from the top of the sound reinforcement space (e.g., the ceiling), part of the side walls, and part of the reverberation into the microphone, significantly increasing the proportion of direct sound from the source in the sound waves entering the microphone.

[0054] To reduce diffraction of microphone sound waves at the edge of the acoustic load plate, the thickness of the acoustic load plate in this embodiment is no more than 1 cm, for example, 0.2 cm. The horizontal distance between the center of the microphone and the center of the acoustic load plate does not exceed 1 cm, meaning that the relative positions of the center of the microphone and the center of the acoustic load plate are either coincident or close to each other.

[0055] When there is one microphone, it is preferably positioned at the center of the acoustic load plate. Similarly, when the microphone is an array microphone, the center of the array microphone is preferably positioned at the center of the acoustic load plate, and the straight-line distance between any microphone unit in the array and any edge of the acoustic load plate is not less than the distance between any two adjacent microphone units. That is, see [link to relevant documentation]. Figure 6 The minimum distance between any microphone unit and the edge of the acoustic load plate is greater than the distance between adjacent microphone units. This further mitigates the diffraction phenomenon of sound waves emitted by the array microphones at the edge of the acoustic load plate. By reducing diffracted sound waves, the phase interference of diffracted sound waves on direct sound waves is reduced, thereby improving the sound reinforcement gain and sound quality. In addition, the acoustic load plate can also suppress sound waves (i.e., sound) from its back side from entering the array microphones, significantly reducing the interference of reflected sound waves on the phase of the array microphones' external suppression. This improves the beam of sound waves emitted by the array microphones, and the external suppression capability is closer to the theoretical external suppression capability. This effectively avoids the problem of low-frequency sound waves, such as reflected and refracted non-direct sound waves, entering the array microphones and causing a decrease in sound reinforcement gain.

[0056] This pickup subsystem can utilize the beam directivity of the array microphone and the high directivity of the aforementioned speaker unit to reduce the proportion of reflected, refracted, or diffracted sound waves entering the pickup subsystem.

[0057] Meanwhile, in this embodiment, the height of the pickup subsystem in the sound reinforcement space is not specifically limited. When the pickup system is directly installed at the top of the sound reinforcement space, such as on the ceiling, the area of ​​the acoustic load plate can be the same as the area of ​​the ceiling.

[0058] The aforementioned acoustic load plate is a board with a flat surface and made of non-metallic materials. For example, it can be a perforated gypsum board or a low-density fiberboard.

[0059] It is worth noting that the speaker subsystem provided in this embodiment enables the mid-to-low frequency sound waves to be directional, thus effectively preventing interference caused by reflection and diffraction of mid-to-low frequency sound waves in the acoustic environment. Therefore, the limitation on the lower limit of the pickup frequency of the pickup subsystem in this embodiment is significantly alleviated. Correspondingly, the longitudinal length of the pickup subsystem can be appropriately increased to help lower its lower pickup frequency limit and improve sound quality.

[0060] In this embodiment, the shape and size of the acoustic load plate are not specifically limited. The surface of the load microphone can be curved or flat, and the edges can be regular or irregular. Please refer to [reference needed]. Figure 7 , Figure 8 and Figure 9 .

[0061] Furthermore, the aforementioned public address system may also include a high-frequency amplification subsystem. The amplification principle of a public address system is as follows: the pickup subsystem receives sound signals (including direct sound from the sound source, noise in the acoustic environment, early reflections, reverberation, and sound waves emitted by the speaker subsystem and then entering the pickup subsystem), converts the sound signals into electrical signals, performs feedback suppression on the sound signals in the speaker subsystem, amplifies the electrical signals, and then radiates them as sound signals through the speaker subsystem. Therefore, when the public address system includes a high-frequency amplification subsystem, the high-frequency amplification subsystem and the aforementioned speaker subsystem can respectively process (i.e., amplify and convert into sound signals for output) the electrical signals corresponding to sound waves of different frequencies. This high-frequency amplification subsystem can, for example, be a highly directional high-pitched horn. The low-frequency response of this speaker unit is omnidirectional. Through phase interference between the linear array units, it forms strong directivity. Within the directivity space, the sound pressure and frequency response in the amplification space are more uniform. Outside the directivity space, the interference causes the sound waves to attenuate sharply, thereby reducing the sound waves emitted by the speaker from entering the pickup subsystem.

[0062] In other words, the high-frequency amplification subsystem is used to process the first electrical signal of the sound wave corresponding to the first frequency, and the loudspeaker subsystem is used to process the second electrical signal of the sound wave corresponding to the second frequency. The first and second electrical signals can be obtained by processing the frequency cutting device, that is, by processing the sound wave (i.e., the sound signal) received by the sound pickup subsystem using the frequency cutting device.

[0063] The aforementioned sound pickup subsystem is used to collect the direct sound emitted by the sound source. This frequency cutting device can be, for example, a high-pass filter or a low-pass filter.

[0064] Specifically, the target frequency range (determined by the actual application scenario and requirements) processed by the sound reinforcement algorithm of the speaker subsystem can be defined as the complete frequency range. The electrical signal corresponding to the acoustic signal within this complete frequency range is filtered and amplified by an LPF low-pass filter before being output to the speaker subsystem, resulting in an amplified mid-to-low frequency acoustic signal. The electrical signal corresponding to the acoustic signal within this complete frequency range is filtered and amplified by an HPF high-pass filter before being output to the high-frequency amplification subsystem (e.g., a highly directional tweeter horn or tweeter line array). The crossover points of the HPF and LPF are connected, and the directivity of the high-frequency amplification subsystem is very sharp. It can be distributed in a specified pattern, similar to the speaker units in the speaker subsystem, such as along the distribution direction of the linear array in the speaker subsystem. This high-frequency amplification subsystem avoids the problem of a sharp increase in the number of high-frequency sidelobes and the peak gain of high-frequency sidelobes, thereby further improving the sound reinforcement gain of the sound reinforcement system containing this speaker array.

[0065] Current loudspeaker systems transmit sound waves over long distances, resulting in significant attenuation of high-frequency signals over the same propagation distance. Therefore, current loudspeaker systems require high sound pressure levels to compensate for this high-frequency attenuation, which increases costs. However, the high-frequency amplification subsystem provided in this application transmits sound waves directionally over short distances. The high-frequency attenuation of tweeter line arrays or tweeter horns is negligible. Even without requiring higher sound pressure compensation, it still exhibits superior sound quality compared to current loudspeaker systems, especially the high-frequency amplification subsystem. The high-frequency amplification subsystem provided in this application only needs to reach a high-frequency limit of 8kHz, meaning the maximum distance between tweeters only needs to be half the wavelength of an 8kHz sound wave. Taking a sound speed of 340 meters per second as an example, the aforementioned half-wavelength is approximately 2.13 centimeters. Considering the small size of tweeters required for indoor sound reinforcement, this setup also possesses ease of implementation.

[0066] The aforementioned first frequency sound wave and second frequency sound wave correspond to the sound signals entering the pickup subsystem, including the direct sound from the sound source and the sound signals corresponding to the low-frequency sound waves that enter the pickup subsystem after emission, diffraction, or refraction.

[0067] The first frequency and the second frequency of the sound wave actually refer to high-frequency sound waves and mid-to-low-frequency sound waves. Wherein, if the first frequency is greater than a preset frequency threshold, then the second frequency is less than or equal to the preset frequency threshold.

[0068] In one embodiment of this application, the speaker subsystem, the high-frequency amplification subsystem, and the pickup subsystem are all located above the amplification system, and the distance between the speaker units in the speaker subsystem and the sound source increases along the arrangement direction.

[0069] Specifically, the distance between the pickup subsystem and the sound source is smaller than the distance between the speaker subsystem or the high-frequency amplification subsystem and the sound source, while the distance between the pickup subsystem and the target audience is greater than the distance between the speaker subsystem or the high-frequency amplification subsystem and the target audience. In other words, throughout the entire amplification space, the pickup subsystem is closer to the sound source, while the speaker subsystem and the high-frequency amplification subsystem are closer to the audience, especially the target audience.

[0070] The target audience here can be all listeners or listeners who are farther away from the sound source. When the target audience is listeners who are farther away from the sound source, non-target listeners receive the direct sound from the sound source, while the target audience receives the direct sound from the sound waves output by the loudspeaker subsystem and the high-frequency amplification subsystem.

[0071] The area above the aforementioned sound reinforcement space refers to the area near the top surface of the sound reinforcement space, such as the area whose height exceeds 1 / 2 of the height of the sound reinforcement space.

[0072] Figure 10This is a schematic diagram illustrating the distribution of a loudspeaker system within a loudspeaker space, as provided in an embodiment of this application. Figure 10 As shown, the sound reinforcement space is rectangular in shape, such as a classroom. The microphone pickup subsystem is positioned diagonally above the sound source; that is, it is an array of microphones attached to the acoustic load plate and suspended from the ceiling diagonally above the lectern. The speaker subsystem and high-frequency amplification subsystem (not shown in the figure) are also positioned above the classroom. Furthermore, the height of the speaker and high-frequency amplification subsystems is slightly lower than the height of the microphone pickup subsystem to further reduce the proportion of mid-to-low frequency sound waves entering the microphone pickup subsystem. The high-frequency amplification subsystem can be arranged in a linear array next to the speaker subsystem, meaning each speaker unit corresponds to a high-frequency unit of the adjacent high-frequency amplification subsystem.

[0073] As can be seen, by arranging the speaker units in a linear array within the speaker subsystem, the directivity of mid-to-low frequency sound waves is significantly increased. This results in a significant increase in the overlap between the coverage areas of the direct sound from the mid-to-low frequency sound waves radiated (i.e., output) and the coverage areas of the direct sound from the high-frequency sound waves, allowing the target audience to enjoy a more uniform listening experience. Furthermore, in a distributed linear array speaker subsystem, each speaker unit uses the same cabinet structure, resulting in a smaller mold size for manufacturing the speaker cabinet. This significantly reduces mold costs and allows for flexible adjustment of the distance between speaker units.

[0074] Meanwhile, since the speaker subsystem provided in this application embodiment is located above the sound reinforcement space (i.e., above the audience's heads, near the ceiling area of ​​the sound reinforcement space; preferably, along the middle area of ​​the sound reinforcement space), and its length is not less than 1 / 2 of the wavelength of the sound wave corresponding to the lowest operating frequency of the aforementioned pickup subsystem, the strong directivity of its linear array speaker units (and high-frequency sound reinforcement subsystem) reduces the average sound path of the first reflected sound wave (mid-low frequency), which increases the average number of reflections and the average propagation path of the reflected sound wave that finally enters the array microphone in the pickup subsystem. As a result, the reflected sound wave entering the array microphone exhibits a high attenuation characteristic compared to the first or second reflected sound wave. That is, by setting the speaker units arranged in a linear array at intervals in this application embodiment, the proportion of sound waves other than the direct sound from the sound source entering the pickup subsystem is significantly reduced; and even if a small amount of emitted sound waves enter the array microphone, the phase interference of the direct sound from the sound source is effectively reduced because of the large attenuation after multiple reflections, thereby improving the sound reinforcement gain. Meanwhile, since the speaker subunit provided in this application embodiment does not change the reverberation time in the classroom, and the user's perceived sound pressure remains unchanged, the high directivity sound field obtained by enhancing the directivity of mid-low frequency sound waves in this application embodiment effectively reduces the reverberation degree of sound waves in the space covered by the directivity of the linear array in the classroom, thereby further improving the sound reinforcement clarity and sound reinforcement gain.

[0075] The minimum straight-line distance between the aforementioned pickup subsystem and the speaker subsystem in the amplification space is not less than the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem.

[0076] Furthermore, for situations with a large sound reinforcement space, such as a volume larger than the coverage space of a single speaker subsystem (i.e., a line array), in order to improve the listening experience for rear-row listeners, in one embodiment of this application, multiple pickup subsystems are spaced apart in the upper area of ​​the sound reinforcement space, and these multiple pickup subsystems are distributed along a direction parallel to the long side of the sound reinforcement space. For example, if the sound reinforcement space is a cuboid, the long side is the longer side of the cuboid. When the sound reinforcement space is a cylinder or the audience is distributed in a circular or other irregular shape, the long side is the diameter of the circumcircle of the plane where the preset position is located.

[0077] The multiple pickup subsystems are arranged linearly, preferably near the center of their respective planes. Each pickup subsystem belongs to a sound reinforcement group comprising two speaker subsystems, positioned on opposite sides of the sound reinforcement space. This sound reinforcement group may also include a high-frequency amplification subsystem, in which case the speaker subsystem and the high-frequency amplification subsystem are arranged adjacent to each other in the sound reinforcement space. Please refer to [reference needed]. Figures 11-12 Combining Figures 11-12It can be seen that the sound lost by beams 101, 102, 201, 202, 301, and 302 is amplified by the speaker subsystems 101, 102, 201, 202, 301, and 302, respectively. The array microphones and amplification speakers are distributed in different areas to achieve zoned amplification: the sound pickup subsystem processes the received sound waves and plays them through speakers far away from the array microphones, so that users can pick up and amplify sound from any location.

[0078] In each amplification group, the minimum straight-line distance between the pickup subsystem and the speaker subsystem in the amplification space is not less than the wavelength of the sound wave corresponding to the lowest operating frequency of the pickup subsystem.

[0079] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A sound amplification system comprising a sound pickup subsystem and a sound reproduction subsystem, characterized by, The loudspeaker system comprises at least two loudspeaker units arranged in a linear array, the length of the loudspeaker system along the linear array direction is not less than 1 / 2 of the wavelength of the sound wave corresponding to the lowest working frequency of the sound pickup system; wherein the distance between any two adjacent loudspeaker units is not less than a preset distance.

2. The sound amplification system of claim 1, wherein, The preset distance is the distance between the two most distant points on any loudspeaker unit along the arrangement direction of the loudspeaker unit.

3. The sound amplification system of claim 1, wherein, The preset distance is 1 / 2 of the wavelength of the sound wave corresponding to the preset frequency threshold.

4. A sound amplification system as claimed in any one of claims 1 to 3, wherein, The deviation distance between the centers of two adjacent loudspeaker units is not greater than 1 / 10 of the wavelength of the sound wave corresponding to the preset frequency threshold.

5. A sound amplification system as claimed in any one of claims 1 to 3, wherein, The sound pickup system comprises a microphone and an acoustic load board attached to the back of the microphone; wherein, The thickness of the acoustic load board is not greater than 1cm; the horizontal distance between the center of the microphone and the center of the acoustic load board is not more than 1cm.

6. A sound amplification system as claimed in claim 5, characterised in that, If the microphone is an array microphone, the straight-line distance between any microphone element in the array microphone and any edge of the acoustic load board is greater than the distance between any two adjacent microphone elements.

7. A sound amplification system as claimed in claim 6, characterised in that, The material of the acoustic load board is a non-metallic material.

8. A sound amplification system as claimed in any one of claims 1-3, 6-7, characterized in that, The sound amplification system further comprises a high-frequency sound amplification system; wherein, The sound pickup system is used to collect direct sound emitted by the sound source, the high-frequency sound amplification system is used to process a first electric signal corresponding to a sound wave of a first frequency, the loudspeaker system is used to process a second electric signal corresponding to a sound wave of a second frequency, the first electric signal and the second electric signal are obtained by frequency cutting, the first frequency is greater than a preset frequency threshold, and the second frequency is less than or equal to the preset frequency threshold.

9. A sound amplification system as claimed in claim 8, wherein, The loudspeaker system, the high-frequency sound amplification system and the sound pickup system are all arranged above the sound amplification space; wherein the distance between the loudspeaker units in the loudspeaker system and the sound source along the arrangement direction increases, the distance between the sound pickup system and the sound source is less than the distance between the loudspeaker system and the sound source, and the distance between the sound pickup system and the target listener is greater than the distance between the loudspeaker system and the target listener.

10. The sound amplification system of claim 8, wherein, A plurality of sound pickup systems are arranged above the sound amplification space and distributed in a direction parallel to the long side of the sound amplification space; wherein each sound pickup system is arranged in a sound amplification group comprising two loudspeaker systems, and the loudspeaker systems in the sound amplification group are arranged in the opposite two side regions of the sound amplification space.

Images