Sound box, audio signal processing method and computer program product

Abstract

The invention provides a sound box, an audio signal processing method and a computer program product. The sound box of the present disclosure comprises: a housing; the first loudspeaker is arranged in the shell; the second loudspeaker is arranged in the shell; and a signal processing circuit configured to receive the first sound channel audio signal, perform filtering processing on the first sound channel audio signal based on the first filter coefficient and the second filter coefficient, respectively, and generate a first loudspeaker driving signal and a second loudspeaker driving signal, the first loudspeaker driving signal is provided for the first loudspeaker, and the second loudspeaker driving signal is provided for the second loudspeaker, so that the first loudspeaker and the second loudspeaker generate sound waves respectively; wherein the sound wave generated by the first loudspeaker and directly propagating to the listening position is at least partially counteracted by the sound wave generated by the second loudspeaker; in addition, sound waves which are generated by the first loudspeaker and are transmitted to the listening position through reflection are not counteracted by sound waves generated by the second loudspeaker.

Description

Technical Field

[0001] This disclosure relates to a speaker, an audio signal processing method, and a computer program product. Background Technology

[0002] In related technologies, to construct a surround sound field, independent speakers need to be installed in different real-world geographical locations such as directly in front of, above, and to the left and right of the listening position. The radiating ports of these speakers face the listening position, allowing sound waves to radiate directly towards the listening position, thus creating a sense of space in the sound heard at that position. However, this installation method has high requirements for installation location and requires a significant amount of space. Summary of the Invention

[0003] This disclosure provides a speaker, an audio signal processing method, and a computer program product.

[0004] According to one aspect of this disclosure, a speaker is provided, comprising: a housing; a first speaker mounted within the housing; a second speaker mounted within the housing, the second speaker having a radiating port facing a listening position and having a different orientation from the radiating port of the first speaker, and the second speaker being disposed near the first speaker; and a signal processing circuit configured to receive a first channel audio signal, filter the first channel audio signal based on a first filter coefficient and a second filter coefficient respectively, generate a first speaker driving signal and a second speaker driving signal, and provide the first speaker driving signal to the first speaker and the second speaker driving signal to the second speaker, such that the first speaker and the second speaker respectively generate sound waves; wherein the sound wave generated by the first speaker that propagates directly to the listening position is at least partially canceled by the sound wave generated by the second speaker; and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled by the sound wave generated by the second speaker.

[0005] According to one technical solution, a first speaker not facing the listening position and a second speaker facing the listening position are configured. A signal processing circuit filters the first channel audio signal based on a first filter coefficient and a second filter coefficient, respectively, to generate a first speaker drive signal and a second speaker drive signal. This ensures that the sound wave directly propagating from the first speaker to the listening position is at least partially canceled by the sound wave generated by the second speaker, while the sound wave reflected from the first speaker to the listening position is not canceled by the sound wave generated by the second speaker. This achieves the preservation of reflected sound from the first speaker and the suppression of direct sound from the first speaker at the listening position, preventing the direct sound from weakening the spatial sense created by the reflected sound of the first speaker. Furthermore, since the first speaker does not need to be installed in the ideal installation position in related technologies to achieve the same spatial sense as a speaker installed in an ideal position, the requirements for the installation position of the first speaker are lower, allowing the first speaker to be integrated with other speakers, thus saving space.

[0006] According to at least one embodiment of the speaker disclosed herein, the signal processing circuit includes: a first FIR filter configured to receive the first channel audio signal and filter the first channel audio signal based on the first filter coefficients to obtain a first filtered signal; a second FIR filter configured to receive the first channel audio signal and filter the first channel audio signal based on the second filter coefficients to obtain a second filtered signal; wherein a first speaker driving signal and a second speaker driving signal are obtained based on the first filtered signal and the second filtered signal, respectively.

[0007] According to the technical solution of this embodiment, the first channel audio signal is filtered by the first fir filter and the second fir filter respectively, so as to ensure the linear phase response and distortion-free characteristics of the first speaker driving signal and the second speaker driving signal, thereby improving the accuracy of sound wave cancellation and the stability of the overall audio processing.

[0008] According to at least one embodiment of the speaker disclosed herein, the signal processing circuit is further configured to receive a second channel audio signal, superimpose the second channel audio signal with a second filtered signal obtained by filtering the first channel audio signal based on the second filter coefficients, and generate a second speaker driving signal, wherein the second channel audio signal and the first channel audio signal are audio signals of different channels.

[0009] According to the technical solution of this embodiment, the second channel audio signal and the second filtered signal are superimposed to generate the second speaker driving signal, so that the sound wave generated by the second speaker can both cancel the direct sound of the first speaker and express the second channel audio signal. Therefore, it is not necessary to configure an additional speaker for playing the second channel audio, saving the number of speakers used. While maintaining the sense of space, the speaker is compatible with playing multi-channel audio.

[0010] According to at least one embodiment of the speaker disclosed herein, the first filter coefficients and the second filter coefficients are determined based on a minimum variance distortionless response algorithm.

[0011] According to the technical solution of this embodiment, the first filter coefficient and the second filter coefficient are determined based on the minimum variance distortionless response algorithm. The filtering objective is to minimize the signal variance and maintain the distortionless response, so that the sound wave generated by the first speaker after filtering is as distortionless as possible while the direct sound of the first speaker is canceled as much as possible, thus ensuring the sense of space created by the reflected sound of the first speaker.

[0012] According to at least one embodiment of the speaker disclosed herein, the first filter coefficients and the second filter coefficients are obtained through the following steps: controlling a first speaker and a second speaker in the speaker to generate sound waves based on a target driving signal; detecting a first transfer function, a second transfer function, and a third transfer function at the listening position of the speaker, wherein the first transfer function is the ratio of the sound wave signal generated by the first speaker based on the target driving signal when it directly propagates to the listening position to the Fourier transform of the target driving signal, and the second transfer function is the ratio of the sound wave signal generated by the first speaker based on the target driving signal when it propagates to the listening position after reflection to the Fourier transform of the target driving signal. The third transfer function information is the ratio of the Fourier transform of the sound wave signal generated by the second loudspeaker based on the target driving signal when it directly propagates to the listening position to the target driving signal; based on the minimum variance distortionless response algorithm, the frequency domain weights of the first loudspeaker and the second loudspeaker are determined according to the first transfer function information, the second transfer function information and the third transfer function information; and the inverse Fourier transforms are performed on the frequency domain weights of the first loudspeaker and the second loudspeaker respectively to obtain the time domain weights of the first loudspeaker and the second loudspeaker, and the time domain weights of the first loudspeaker are used as the first filter coefficients and the time domain weights of the second loudspeaker are used as the second filter coefficients.

[0013] According to the technical solution of this embodiment, various transfer function information is measured at the listening position, and then the first filter coefficient and the second filter coefficient are accurately determined by combining the minimum variance distortionless response algorithm, thereby realizing the environmental adaptability of the first filter coefficient and the second filter coefficient, and ensuring the suppression of the direct sound from the first speaker and the preservation of the reflected sound from the first speaker at the listening position.

[0014] According to at least one embodiment of the speaker disclosed herein, based on the minimum variance distortionless response algorithm, the frequency domain weights of the first speaker and the second speaker are determined according to the first transfer function information, the second transfer function information, and the third transfer function information. This includes: generating a speaker array response vector for a direct propagation path based on the first transfer function information and the third transfer function information, wherein the components of the speaker array response vector for the direct propagation path are the first transfer function information and the third transfer function information; and performing an outer product operation between the conjugate transpose of the speaker array response vector for the direct propagation path and the speaker array response vector for the direct propagation path to obtain the spatial covariance of the direct propagation path. The variance matrix; based on the second transfer function information, a loudspeaker array response vector for the reflection propagation path is generated, wherein the components of the loudspeaker array response vector for the reflection propagation path are the second transfer function information; and the frequency domain weight vector is obtained by multiplying the inverse of the spatial covariance matrix of the direct propagation path with the loudspeaker array response vector for the reflection propagation path and dividing by a normalization factor, wherein the components of the frequency domain weight vector are the frequency domain weights of the first loudspeaker and the frequency domain weights of the second loudspeaker, and the normalization factor is the inner product between the conjugate transpose of the loudspeaker array response vector for the reflection propagation path and the result of weighting the loudspeaker array response vector for the reflection propagation path by the spatial covariance matrix of the direct propagation path.

[0015] According to the technical solution of this embodiment, the spatial covariance matrix of the direct propagation path and the loudspeaker array response vector of the reflected propagation path are first generated, and then the two are processed accordingly to accurately determine the frequency domain weight of the first loudspeaker and the frequency domain weight of the second loudspeaker, so as to achieve the suppression of the direct sound of the first loudspeaker and the preservation of the reflected sound of the first loudspeaker at the listening position, thereby reducing the interference of the direct sound of the first loudspeaker on the spatial sense created by the reflected sound of the first loudspeaker.

[0016] According to at least one embodiment of the present disclosure, the housing includes a front panel and a circumferential side panel connected to the front panel, wherein the radiation port of the first speaker faces the circumferential side panel and the radiation port of the second speaker faces the front panel.

[0017] According to the technical solution of this embodiment, the first speaker radiating port faces the circumferential side panel and the second speaker radiating port faces the front panel, so that the sound waves generated by the first speaker mainly propagate to the listening position through the reflection propagation path and the sound waves generated by the second speaker mainly propagate to the listening position through the direct propagation path. This achieves the suppression of the direct sound of the first speaker and the preservation of the reflected sound of the first speaker at the listening position, reducing the interference of the direct sound of the first speaker on the spatial sense created by the reflected sound of the first speaker.

[0018] According to at least one embodiment of the speaker disclosed herein, the circumferential side panel includes a side panel and a top panel; when the first speaker is a side surround channel speaker, the radiation port of the side surround channel speaker faces the side panel, and the first channel audio signal is a side surround channel audio signal; when the first speaker is a sky channel speaker, the radiation port of the sky channel speaker faces the top panel, and the first channel audio signal is a sky channel audio signal.

[0019] According to the technical solution of this embodiment, the orientation of the speaker radiation port is configured according to the channel type of the audio output by the first speaker, so that the sound waves generated by the first speaker can reach the listening position through reflection. Thus, the first speaker does not need to be installed in the ideal installation position in the related technology to basically achieve the sense of space created by the speaker installed in the ideal installation position in the related technology, thereby improving the speaker's ability to reproduce surround sound or sky sound.

[0020] According to at least one embodiment of the speaker disclosed herein, the orientation of the radiating port of the first speaker is at an angle to the normal of the circumferential side panel, and the orientation of the radiating port of the second speaker is parallel to the normal of the front panel.

[0021] According to the technical solution of this embodiment, by setting the angle between the orientation of the first speaker radiating port and the normal of the circumferential side plate, and the parallel relationship between the orientation of the second speaker radiating port and the normal of the front panel, the reflection propagation path of the sound wave generated by the first speaker and the direct propagation path of the sound wave generated by the second speaker are optimized, thereby ensuring that the reflected sound of the first speaker propagates to the listening position more effectively, while maintaining the precise suppression of the direct sound from the first speaker by the second speaker, and improving the overall acoustic performance.

[0022] According to at least one embodiment of the speaker disclosed herein, the circumferential side plate is provided with an opening, and the radiation port of the first loudspeaker is connected to the opening via a waveguide horn.

[0023] According to the technical solution of this embodiment, the waveguide horn is used to improve the directionality and efficiency of the sound waves radiated by the first loudspeaker, ensuring that the sound waves have better focusing and transmission characteristics when radiating from the opening, increasing the energy of the sound waves propagating in the axial direction of the first loudspeaker, and thus increasing the intensity of the sound reflected by the first loudspeaker.

[0024] According to at least one embodiment of the speaker of the present disclosure, the distance between the geometric center of the diaphragm of the first speaker and the geometric center of the diaphragm of the second speaker is less than or equal to 17 cm.

[0025] According to the technical solution of this embodiment, the second speaker is arranged near the first speaker, which can reduce the phase delay and spatial difference between the first speaker and the second speaker, and ensure that the second speaker suppresses the direct sound of the first speaker more accurately.

[0026] According to another aspect of this disclosure, an audio signal processing method is provided, applied to a speaker in any embodiment of this disclosure. The method includes: receiving a first channel audio signal; filtering the first channel audio signal based on a first filter coefficient and a second filter coefficient to generate a first speaker driving signal and a second speaker driving signal; and providing the first speaker driving signal to the first speaker and the second speaker driving signal to the second speaker, such that the first speaker and the second speaker respectively generate sound waves; wherein the sound wave generated by the first speaker that directly propagates to the listening position is at least partially canceled by the sound wave generated by the second speaker; and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled by the sound wave generated by the second speaker.

[0027] According to another aspect of the technical solution of this disclosure, the first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient to generate the first speaker driving signal and the second speaker driving signal, respectively. This makes the sound wave directly propagating to the listening position generated by the first speaker at least partially canceled by the sound wave generated by the second speaker, and the sound wave propagating to the listening position after reflection generated by the first speaker is not canceled by the sound wave generated by the second speaker. This achieves the preservation of the reflected sound of the first speaker and the suppression of the direct sound of the first speaker at the listening position, and avoids the direct sound of the first speaker weakening the sense of space created by the reflected sound of the first speaker.

[0028] An audio signal processing method according to at least one embodiment of the present disclosure filters a first channel audio signal based on a first filter coefficient and a second filter coefficient to generate a first speaker driving signal and a second speaker driving signal, comprising: filtering the first channel audio signal based on the first filter coefficient and the second filter coefficient to obtain a first filtered signal and a second filtered signal; and obtaining the first speaker driving signal and the second speaker driving signal based on the first filtered signal and the second filtered signal, respectively.

[0029] According to the technical solution of this embodiment, the first speaker driving signal and the second speaker driving signal are generated after filtering, thereby enabling precise control of the output characteristics of the first speaker and the second speaker, improving the accuracy of sound wave cancellation and the stability of the overall audio processing.

[0030] An audio signal processing method according to at least one embodiment of the present disclosure filters a first channel audio signal based on a first filter coefficient and a second filter coefficient to generate a first speaker driving signal and a second speaker driving signal, comprising: receiving a second channel audio signal, wherein the second channel audio signal and the first channel audio signal are audio signals from different channels; filtering the first channel audio signal based on the first filter coefficient and the second filter coefficient to obtain a first filtered signal and a second filtered signal; superimposing the second channel audio signal and the second filtered signal to obtain a superimposed audio signal; and obtaining the first speaker driving signal and the second speaker driving signal based on the first filtered signal and the superimposed signal, respectively.

[0031] According to the technical solution of this embodiment, the second channel audio signal is superimposed with the second filtered signal to generate the second speaker driving signal, so that the sound wave generated by the second speaker can both cancel the direct sound of the first speaker and express the second channel audio signal. Thus, it is not necessary to configure an additional speaker for playing the second channel audio, saving the number of speakers used, and making the speaker compatible with playing multi-channel audio while maintaining the sense of space.

[0032] According to another aspect of this disclosure, a computer program product is provided, including a computer program that, when executed by a processor, implements an audio signal processing method according to any embodiment of this disclosure. Attached Figure Description

[0033] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0034] Figure 1 This is a schematic structural block diagram of a speaker according to one embodiment of the present disclosure.

[0035] Figure 2 This is a schematic structural block diagram of a speaker according to another embodiment of the present disclosure.

[0036] Figure 3 This is a schematic diagram illustrating the process of calibrating the first filter coefficients and the second filter coefficients according to one embodiment of the present disclosure.

[0037] Figure 4 This is a schematic diagram illustrating the process of determining the frequency domain weights of the first loudspeaker and the second loudspeaker according to one embodiment of the present disclosure.

[0038] Figure 5 This is a schematic diagram illustrating a usage scenario of a speaker according to one embodiment of the present disclosure.

[0039] Figure 6 This is a schematic diagram of the frequency response curves of the sound waves radiated by the front surround channel speaker of the second speaker according to an embodiment of the present disclosure, measured at various angles.

[0040] Figure 7 This is a schematic diagram of the frequency response curves of the sound waves radiated by the rear surround channel speaker of the second speaker according to an embodiment of the present disclosure, measured at various angles.

[0041] Figure 8 This is a comparative schematic diagram of the frequency response at 15° and 110° according to one embodiment of the present disclosure.

[0042] Figure 9 This is a schematic diagram showing the installation effect of a first loudspeaker according to one embodiment of the present disclosure.

[0043] Figure 10 This is a schematic diagram of the frequency response curves on the shaft of the first speaker before and after installation according to one embodiment of this disclosure.

[0044] Figure 11 This is a schematic diagram of the installation of a first loudspeaker and a waveguide horn according to one embodiment of the present disclosure.

[0045] Figure 12 This is a schematic diagram of the installation of a first loudspeaker and a waveguide horn according to another embodiment of the present disclosure.

[0046] Figure 13 This is a schematic diagram of the installation of a first loudspeaker and a waveguide horn according to yet another embodiment of this disclosure.

[0047] Figure 14This is a schematic diagram of the frequency response curves of the first loudspeaker before and after oblique cutting according to one embodiment of the present disclosure.

[0048] Figure 15 This is a schematic diagram of the off-axis energy isolation of the first loudspeaker before and after oblique cutting, according to one embodiment of the present disclosure.

[0049] Figure 16 This is a schematic flowchart of an audio signal processing method according to one embodiment of the present disclosure.

[0050] Figure 17 This is a schematic diagram illustrating the process of generating a first speaker drive signal and a second speaker drive signal according to one embodiment of the present disclosure.

[0051] Figure 18 This is a schematic diagram illustrating the process of generating a first speaker drive signal and a second speaker drive signal according to another embodiment of the present disclosure.

[0052] Explanation of reference numerals in the attached figures: Speaker 1000, housing 100, front panel 101, circumferential side panel 102, first speaker 200, second speaker 300, signal processing circuit 400, first FIR filter 401, second FIR filter 402, power amplifier 403, adder 404, waveguide horn 500. Detailed Implementation

[0053] The present disclosure will now be described in further detail with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0054] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] The installation method of installing speakers with their radiating ports facing the listening position in different actual geographical locations is often difficult to achieve in actual home or small venues due to space limitations or aesthetic considerations. In particular, speakers with ideal installation positions at the top or side are often installed in non-ideal positions, which in turn interferes with the spatial sense of the sound heard at the listening position.

[0056] After careful research, the inventors discovered that when the speaker's radiating port faces the ceiling or side wall (i.e., not towards the listening position), the ceiling or side wall can reflect the sound waves directly radiated by the speaker. Thus, the reflected sound heard at the listening position is approximately the direct sound of a speaker installed at a certain height or width in a real geographical location and facing the listening position. Therefore, by adjusting the orientation of the radiating port, a virtual sound source with a certain height or width can be formed. This allows the virtual sound source formed by a speaker in an ideal installation position in a non-related technology to basically achieve the spatial sense created by a speaker in an ideal installation position in a related technology within a limited space, reducing the requirements for installation position and space occupation.

[0057] However, further research by the inventors revealed that, due to the limitations of the speaker's physical radiation characteristics, a speaker whose radiating port does not face the listening position inevitably generates direct radiated sound waves toward the listening position during operation. These direct radiated sound waves arrive at the listening position before the reflected sound waves. According to relevant principles of psychoacoustics (such as the Haas effect and masking effect), in this situation, the direct and reflected sound from the speaker will compete, leading to a reduction in the apparent source width (ASW), thus weakening the sense of space.

[0058] To address this, the present disclosure proposes the following technical solution: A first speaker not facing the listening position and a second speaker facing the listening position are configured. A signal processing circuit filters the first channel audio signal based on a first filter coefficient and a second filter coefficient, respectively, to generate a first speaker drive signal and a second speaker drive signal. This ensures that the sound wave directly propagating from the first speaker to the listening position is at least partially canceled by the sound wave generated by the second speaker, while the sound wave reflected from the first speaker to the listening position is not canceled by the sound wave generated by the second speaker. This achieves the preservation of reflected sound from the first speaker and the suppression of direct sound from the first speaker at the listening position, preventing the direct sound from weakening the spatial sense created by the reflected sound of the first speaker. Furthermore, since the first speaker does not need to be installed in the ideal installation position as in related technologies to achieve the same spatial sense as a speaker installed in an ideal position, the requirements for the installation position of the first speaker are lower, allowing the first speaker to be integrated with other speakers, thus saving space.

[0059] In this disclosure, direct sound refers to sound emitted by a loudspeaker that travels directly to the listening position without reflection. Reflected sound refers to sound emitted by a loudspeaker that encounters an obstacle (such as a wall or ceiling) and is reflected to the listening position. The radiating port of a loudspeaker refers to the opening through which the loudspeaker emits sound waves into the external space.

[0060] Figure 1 A schematic structural block diagram of a speaker according to one embodiment of this disclosure is shown. Figure 1 The speaker 1000 shown includes: a housing 100; a first speaker 200 installed within the housing 100; a second speaker 300 installed within the housing 100, the radiating port of the second speaker 300 facing the listening position and having a different orientation from the radiating port of the first speaker 200, and the second speaker 300 being disposed near the first speaker 200; and a signal processing circuit 400 configured to receive a first channel audio signal, filter the first channel audio signal based on a first filter coefficient and a second filter coefficient respectively, generate a first speaker driving signal and a second speaker driving signal, and provide the first speaker driving signal to the first speaker 200 and the second speaker driving signal to the second speaker 300, so that the first speaker 200 and the second speaker 300 respectively generate sound waves; wherein the sound wave generated by the first speaker 200 that propagates directly to the listening position is at least partially canceled by the sound wave generated by the second speaker 300; and the sound wave generated by the first speaker 200 that propagates to the listening position after reflection is not canceled by the sound wave generated by the second speaker 300.

[0061] The housing 100 may be elongated. The number of first speakers 200 and second speakers 300 within the housing 100 may be one or more. In one possible implementation, the second speakers 300 within the housing 100 correspond one-to-one with the first speakers 200, thus one second speaker 300 is used to suppress the direct sound from one first speaker 200, resulting in better suppression. In another possible implementation, multiple first speakers 200 within the housing 100 correspond to one second speaker 300. The driving signal for one second speaker 300 may be a signal formed by superimposing multiple driving signals corresponding to each first speaker 200, thereby suppressing the direct sound from multiple first speakers 200 through one second speaker 300, saving cost and space.

[0062] The first channel may include side surround channels and / or sky channels. In addition, one or more third speakers for outputting second channel audio may be configured within the housing 100. The second channel audio is different from the first channel audio corresponding to the first channel audio signal. The second channel may include one or more of the left channel, center channel, and right channel.

[0063] The signal processing circuit 400 may include a DSP chip, which can be connected to the first speaker 200 and the second speaker 300 respectively. The DSP chip can be configured to: receive a first channel audio signal; filter the first channel audio signal based on a first filter coefficient and a second filter coefficient respectively to generate a first speaker driving signal and a second speaker driving signal; and provide the first speaker driving signal to the first speaker 200 and the second speaker driving signal to the second speaker 300. In this way, by utilizing the powerful real-time computing capabilities of the DSP chip, digital filtering based on the first and second filter coefficients can be implemented accurately and flexibly, ensuring that the generated first speaker driving signal and second speaker driving signal can work effectively together.

[0064] The first and second filter coefficients can be pre-calibrated and stored in the signal processing circuit 400, thereby improving the efficiency and real-time performance of audio signal processing.

[0065] According to the speaker 1000 of this disclosure, a first speaker 200 not facing the listening position and a second speaker 300 facing the listening position are configured. The first channel audio signal is filtered by the signal processing circuit 400 based on the first filter coefficient and the second filter coefficient to generate the first speaker driving signal and the second speaker driving signal, respectively. This makes the sound wave directly propagated to the listening position by the first speaker 200 at least partially canceled by the sound wave generated by the second speaker 300, and the sound wave propagated to the listening position by the reflection of the first speaker 200 is not canceled by the sound wave generated by the second speaker 300. This achieves the preservation of the reflected sound of the first speaker 200 and the suppression of the direct sound of the first speaker 200 at the listening position, and avoids the direct sound of the first speaker 200 weakening the sense of space created by the reflected sound of the first speaker 200. At the same time, since the first speaker 200 does not need to be installed in the ideal installation position in the related technology to basically achieve the sense of space created by the speaker installed in the ideal installation position in the related technology, the requirements for the installation position of the first speaker 200 are lower, which allows the first speaker 200 to be integrated with other speakers, thereby saving space.

[0066] Please combine Figure 2 In some embodiments, the signal processing circuit 400 includes: a first FIR filter 401 configured to receive a first channel audio signal and filter the first channel audio signal based on first filter coefficients to obtain a first filtered signal; and a second FIR filter 402 configured to receive the first channel audio signal and filter the first channel audio signal based on second filter coefficients to obtain a second filtered signal; wherein a first speaker driving signal and a second speaker driving signal are obtained based on the first filtered signal and the second filtered signal, respectively.

[0067] For example, considering the phase-sensitive nature of beamforming, the first channel audio signal is filtered by combining the excellent linear phase, unconditional stability, and ease of implementing arbitrary amplitude and frequency characteristics of the FIR filter. The first FIR filter 401 and the second FIR filter 402 can be implemented very conveniently in the DSP chip, with low computational resource consumption and easy productization.

[0068] For example, after obtaining the first filtered signal and the second filtered signal, the power amplifier 403 can amplify the power of the first filtered signal and the second filtered signal respectively to obtain the first speaker driving signal and the second speaker driving signal. The first speaker driving signal and the second speaker driving signal can directly drive the first speaker 200 and the second speaker 300 to generate sound waves.

[0069] According to the speaker 1000 of the above embodiment, the first channel audio signal is filtered by the first fir filter 401 and the second fir filter 402 respectively, so as to ensure the linear phase response and distortion-free characteristics of the first speaker driving signal and the second speaker driving signal, thereby improving the accuracy of sound wave cancellation and the stability of the overall audio processing.

[0070] Please combine Figure 2 In some embodiments, the signal processing circuit 400 is further configured to receive a second channel audio signal, superimpose the second channel audio signal with a second filtered signal obtained by filtering the first channel audio signal based on a second filter coefficient, and generate a second speaker driving signal, wherein the second channel audio signal and the first channel audio signal are audio signals of different channels.

[0071] In one example, the first channel audio signal is the side surround channel audio signal, and the second channel audio signal is either the left channel audio signal or the right channel audio signal. Since the distance between the second speaker 300 and the first speaker 200 is small in order to ensure the cancellation bandwidth performance of the second speaker 300, the apparent sound field width of the left and right stereo can be improved when the second speaker 300 is used as both the left and right channel speakers.

[0072] The second channel audio signal and the second filtered signal can be superimposed using adder 404.

[0073] According to the speaker 1000 of the above embodiment, the second channel audio signal and the second filtered signal are superimposed to generate the second speaker driving signal, so that the sound wave generated by the second speaker 300 can both cancel the direct sound of the first speaker 200 and express the second channel audio signal. Therefore, it is not necessary to configure an additional speaker for playing the second channel audio, saving the number of speakers used. While maintaining the sense of space, the speaker 1000 is compatible with playing multi-channel audio.

[0074] In some implementations, the first filter coefficients and the second filter coefficients are determined based on the minimum variance distortionless response algorithm.

[0075] According to the speaker 1000 of the above embodiment, the first filter coefficient and the second filter coefficient are determined based on the minimum variance distortionless response algorithm. The filtering objective is to minimize the signal variance and maintain the distortionless response, so that the sound wave generated by the first speaker 200 after filtering is as distortionless as possible, while the direct sound of the first speaker 200 is canceled as much as possible, thus ensuring the sense of space created by the reflected sound of the first speaker 200.

[0076] Understandably, conventional beamforming (CBF) algorithms introduce time delays / phase shifts into each element of a speaker array, superimposing the energy of each speaker in the direction requiring enhanced focusing. While this achieves a degree of energy convergence and beam rotation to ensure a sense of space, the broadband nature of audible sound necessitates a large speaker array for lower frequencies and a sufficient number of speaker units for the same array size to ensure the spacing between adjacent units is less than half the wavelength corresponding to the highest operating frequency. This presents a contradiction. Furthermore, if conventional beamforming is used to ensure a sense of space, the acoustic structures required to control the directivity of low-frequency sound waves are large due to their longer length, leading to inconvenience and site limitations. In other words, without using a minimum variance distortion-free response beamforming algorithm to control the sound waves generated by the first speaker 200 and the second speaker 300, either a larger number of speakers are needed, increasing complexity and cost; or the acoustic structures are too large for convenient use; or the acoustic structures, while smaller, may not produce satisfactory results. Furthermore, commercially available soundbars typically employ fewer speaker units to reduce costs and simplify systems, further exacerbating the aforementioned challenges. Additionally, conventional beamforming algorithms, which introduce time delays or phase shifts into each element, can only cover a narrow bandwidth and cannot adequately cover the low-frequency band of audible sound signals spanning nearly two to three octaves.

[0077] In some implementations, the first filter coefficients and the second filter coefficients can be obtained by means of, for example Figure 3The steps S110 to S140 shown are pre-calibrated.

[0078] In step S110, based on the target driving signal, the first speaker 200 and the second speaker 300 in the speaker 1000 are controlled to generate sound waves respectively.

[0079] In step S120, at the listening position of the speaker 1000, the first transfer function information, the second transfer function information, and the third transfer function information are detected respectively. The first transfer function information is the ratio of the sound wave signal generated by the first speaker 200 based on the target driving signal when it directly propagates to the listening position to the Fourier transform of the target driving signal. The second transfer function information is the ratio of the sound wave signal generated by the first speaker 200 based on the target driving signal when it propagates to the listening position after reflection to the Fourier transform of the target driving signal. The third transfer function information is the ratio of the sound wave signal generated by the second speaker 300 based on the target driving signal when it directly propagates to the listening position to the Fourier transform of the target driving signal.

[0080] For example, the speaker 1000 can be placed in an anechoic chamber or a live listening environment, and then, based on the target driving signal, the first speaker 200 and the second speaker 300 in the speaker 1000 can be controlled to generate sound waves, and the first transfer function information, the second transfer function information and the third transfer function information can be detected at the listening position in front of the speaker 1000.

[0081] In step S130, based on the minimum variance distortionless response algorithm, the frequency domain weights of the first loudspeaker 200 and the second loudspeaker 300 are determined according to the first transfer function information, the second transfer function information and the third transfer function information.

[0082] For example, the first transfer function information, the second transfer function information, and the third transfer function information can be substituted into the relevant formulas of the minimum variance distortionless response algorithm to solve for the frequency domain weights of the first speaker 200 and the second speaker 300.

[0083] In step S140, inverse Fourier transforms are performed on the frequency domain weights of the first speaker 200 and the second speaker 300 respectively to obtain the time domain weights of the first speaker 200 and the second speaker 300. The time domain weights of the first speaker 200 are used as the first filter coefficients and the time domain weights of the second speaker 300 are used as the second filter coefficients.

[0084] According to the speaker 1000 of the above embodiment, various transfer function information is measured at the listening position, and then the first filter coefficient and the second filter coefficient are accurately determined by combining the minimum variance distortionless response algorithm, thereby realizing the environmental adaptability of the first filter coefficient and the second filter coefficient, and ensuring that the direct sound of the first speaker 200 and the reflected sound of the first speaker 200 are suppressed at the listening position.

[0085] Regarding step S130, in some embodiments, it may include, for example... Figure 4 Steps S131 to S134 are shown.

[0086] In step S131, a loudspeaker array response vector for the direct propagation path is generated based on the first transfer function information and the third transfer function information. The components of the loudspeaker array response vector for the direct propagation path are the first transfer function information and the third transfer function information.

[0087] In step S132, the conjugate transpose of the loudspeaker array response vector of the direct propagation path is multiplied by the loudspeaker array response vector of the direct propagation path to obtain the spatial covariance matrix of the direct propagation path.

[0088] In step S133, a loudspeaker array response vector for the reflection propagation path is generated based on the second transfer function information, wherein the components of the loudspeaker array response vector for the reflection propagation path are the second transfer function information.

[0089] In step S134, the inverse of the spatial covariance matrix of the direct propagation path is multiplied by the loudspeaker array response vector of the reflection propagation path and then divided by a normalization factor to obtain a frequency domain weight vector. The components of the frequency domain weight vector are the frequency domain weights of the first loudspeaker 200 and the second loudspeaker 300. The normalization factor is the inner product between the conjugate transpose of the loudspeaker array response vector of the reflection propagation path and the result of weighting the loudspeaker array response vector of the reflection propagation path by the spatial covariance matrix of the direct propagation path.

[0090] For example, in the minimum variance distortionless response algorithm for a loudspeaker array, the frequency domain weight vector It can be calculated using the following formula: ,in, , The spatial covariance matrix of the direct propagation path. The loudspeaker array response vector for the direct propagation path. This is the loudspeaker array response vector along the reflection propagation path.

[0091] Specifically, for a speaker array consisting of a first speaker and a second speaker, assuming These are the frequency domain weights of the first and second loudspeakers at each frequency point, which need to be calculated. These frequency domain weights are the components of the frequency domain weight vector. Since it is a complex number, this frequency domain weight can weight and adjust the amplitude and phase of the audio signals acting on the first and second speakers. Furthermore, in the minimum variance distortionless response algorithm for the speaker array, it is desired that the signal received at the listening position from the reflected propagation path of the speaker array is distortion-free, and that the variance of the signal received at the listening position from the direct propagation path of the speaker array is minimized.

[0092] Furthermore, the constraint that the signal received at the listening position from the reflected propagation path of the loudspeaker array is distortion-free can be expressed as follows: .in, , is the weighted vector formed by the frequency domain weights of the first and second loudspeakers at each frequency point. Let be the response vector of the speaker array along the reflection propagation path. Since the first speaker is not oriented towards the listening position while the second speaker is, the signal received at the listening position from the speaker array along the reflection propagation path is mainly the signal from the first speaker's reflection propagation path. The component is mainly the ratio of the Fourier transform of the sound wave signal generated by the first loudspeaker based on the target driving signal when it propagates to the listening position after reflection to the target driving signal (i.e., the second transfer function information), while The component corresponding to the second speaker can be ignored, or replaced by a preset value.

[0093] Next, the constraint that the variance of the signal received at the listening position from the direct propagation path of the loudspeaker array is minimized can be expressed as: .in, The loudspeaker array response vector represents the direct propagation path. Since the first loudspeaker is not oriented towards the listening position while the second loudspeaker is, the signal received at the listening position from the direct propagation path of the loudspeaker array includes the signal from the direct propagation path of the first loudspeaker and the signal from the direct propagation path of the second loudspeaker. Therefore, One component is the ratio of the sound wave signal generated by the first loudspeaker based on the target driving signal when it propagates directly to the listening position to the Fourier transform of the target driving signal (i.e., the first transfer function information). The other component is the ratio of the sound wave signal generated by the second loudspeaker based on the target driving signal when it propagates directly to the listening position to the Fourier transform of the target driving signal (i.e., the third transfer function information). ,Right now , The spatial covariance matrix of the direct propagation path (usually a multidimensional matrix that describes the statistical relationship between the signal source and the interference).

[0094] The above two constraints constitute a typical quadratic optimization problem, which can be solved using the Lagrange multiplier method. The specific process is as follows: First, define... Next, in order to seek ,right about Differentiating and setting it to zero, we obtain the equation ,Right now Next, assume Reversible, then Substitute this result into the constraints. From this, we can obtain Then, due to It is a Hermitian matrix, therefore, , that is The transformation can be obtained Finally, Back to ,available .

[0095] Understandably, for minimum variance distortionless response algorithms of receiving arrays such as microphones, where... Corresponding to the snapshot vector of the received data from the receiving array, covariance It is obtained by observing a segment of received data and using that data to estimate the sample's covariance matrix. The specific formula is as follows: , This refers to the number of snapshots for receiving data. However, for the minimum variance distortion-free response algorithm for speaker arrays disclosed herein, The loudspeaker array response vector is the one with the direct propagation path. Its components can be obtained by directly measuring the transfer function information of each loudspeaker in the loudspeaker array in an anechoic chamber or a live listening environment.

[0096] According to the speaker 1000 of the above embodiment, the spatial covariance matrix of the direct propagation path and the speaker array response vector of the reflected propagation path are first generated, and then the two are processed accordingly to accurately determine the frequency domain weight of the first speaker 200 and the frequency domain weight of the second speaker 300. This enables the suppression of the direct sound of the first speaker 200 and the preservation of the reflected sound of the first speaker 200 at the listening position, thereby reducing the interference of the direct sound of the first speaker 200 on the spatial sense created by the reflected sound of the first speaker 200.

[0097] In the listening position direction, the second speaker can be selected to have a response significantly higher than the first speaker by 6-15 dB. This allows the second speaker to deliver only a smaller signal energy to eliminate unwanted direct sound from the first speaker, since the first speaker has less sound energy in that direction. Simultaneously, the second speaker can still play signals from other channels, thereby reducing system size and cost.

[0098] In some embodiments, the housing 100 includes a front panel 101 and a circumferential side panel 102 connected to the front panel 101, with the radiation port of the first speaker 200 facing the circumferential side panel 102 and the radiation port of the second speaker 300 facing the front panel 101.

[0099] The front panel 101 and the axial side panel can form a receiving cavity, in which the first speaker 200 and the second speaker 300 can be housed.

[0100] For example, since the front panel 101 of the speaker 1000 typically faces directly towards the listener at the listening position, when the radiating port of the second speaker 300 faces the front panel 101, the second speaker 300 also faces directly towards the listener (e.g., Figure 5 As shown), the sensitivity of the direct sound from the listener's direction of the second speaker 300 is 6-15 dB higher than that of the direct sound from the listener's direction of the first speaker 200, with ample power margin, and will not introduce distortion noise when playing superimposed signals from other channels.

[0101] According to the speaker 1000 of the above embodiment, the radiation port of the first speaker 200 faces the circumferential side panel 102, and the radiation port of the second speaker 300 faces the front panel 101. This makes the sound waves generated by the first speaker 200 mainly propagate to the listening position through the reflection propagation path, and the sound waves generated by the second speaker 300 mainly propagate to the listening position through the direct propagation path. This achieves the suppression of the direct sound of the first speaker 200 and the preservation of the reflected sound of the first speaker 200 at the listening position, reducing the interference of the direct sound of the first speaker 200 on the spatial sense created by the reflected sound of the first speaker 200.

[0102] In some embodiments, the circumferential side panel 102 includes a side panel and a top panel; when the first speaker 200 is a side surround channel speaker, the radiation port of the side surround channel speaker faces the side panel, and the first channel audio signal is a side surround channel audio signal; when the first speaker 200 is a sky channel speaker, the radiation port of the sky channel speaker faces the top panel, and the first channel audio signal is a sky channel audio signal.

[0103] According to the speaker 1000 of the above embodiment, the orientation of the speaker radiating port is configured according to the channel type of the audio output by the first speaker 200, so that the sound waves generated by the first speaker 200 can reach the listening position through reflection. Thus, the first speaker 200 does not need to be installed in the ideal installation position in the related technology to basically achieve the sense of space created by the speaker installed in the ideal installation position in the related technology, thereby improving the speaker 1000's ability to reproduce surround sound or sky sound.

[0104] In some embodiments, the orientation of the radiating port of the first speaker 200 is at an angle to the normal of the circumferential side panel 102, and the orientation of the radiating port of the second speaker 300 is parallel to the normal of the front panel 101.

[0105] In one example, the first speaker 200 is a side surround channel speaker. With the angle between the radiating port of the side surround channel speaker and the normal to the outer surface of the side panel being 15°, the frequency response of the sound waves radiated by the front surround channel speaker of the second speaker 300, measured at various angles, is as follows: Figure 6 As shown, the frequency response of the sound waves radiated by the rear surround channel speaker of the second speaker 300 at various angles is as follows: Figure 7 As shown, if the angle between the line connecting the listening position and the side surround channel speakers and the normal to the outer surface of the side panel is 110°, then... Figure 6 and Figure 7 The frequency response at 15° and 110° can be combined to obtain Figure 8 , Figure 8 In this context, RS-15° represents the frequency response in the direction 15° before configuration, RS-110° represents the frequency response in the direction 110° before configuration, MVDR-15° represents the frequency response in the direction 15° after configuration, and MVDR-110° represents the frequency response in the direction 110° after configuration. Figure 8 As can be seen, approximately 5-10 dB of cancellation is achieved in the listener direction below 2 kHz, and there is almost no effect on axial energy across the entire frequency range. The "axis" of the first loudspeaker 200 can be understood as a straight line perpendicular to the diaphragm plane, originating from the geometric center of the diaphragm of the first loudspeaker 200.

[0106] According to the speaker 1000 of the above embodiment, by setting the angle between the orientation of the first speaker 200's radiating port and the normal of the circumferential side panel 102, and the parallel relationship between the orientation of the second speaker 300's radiating port and the normal of the front panel 101, the reflection propagation path of the sound waves generated by the first speaker 200 and the direct propagation path of the sound waves generated by the second speaker 300 are optimized. This ensures that the reflected sound from the first speaker 200 propagates more effectively to the listening position, while maintaining the precise suppression of the direct sound from the first speaker 200 by the second speaker 300, thereby improving the overall acoustic performance.

[0107] In some embodiments, the circumferential side plate 102 is provided with an opening, and the radiation port of the first loudspeaker 200 is connected to the opening via a waveguide horn 500.

[0108] For example, if the first speaker 200 adopts such Figure 9 If the speaker is installed at an angle directly within the housing 100 as shown, the right-angled edge of the circumferential side plate of the housing 100 will scatter the sound waves emitted by the first speaker 200 and interfere with the energy propagating along the axis of the first speaker 200, resulting in an unfavorable destructive effect in the mid-to-high frequency range. The frequency response curves of the first speaker 200 along the axis before and after installation are as follows: Figure 10 As shown.

[0109] In this disclosure, the radiation port of the first loudspeaker 200 is connected to the opening via a hyperbolic waveguide horn 500. Based on basic acoustic principles, this horn shape can guide and concentrate sound wave energy, enhance the energy propagating along the axis of the first loudspeaker 200, and suppress off-axis energy. The smooth, gradually changing curved surface structure of the hyperbolic waveguide horn 500 avoids unfavorable sound wave scattering caused by abrupt changes in cross-section such as right-angled sides, thereby preventing the scattered sound waves from interfering with the sound waves along the axis of the first loudspeaker 200 and ensuring effective sound wave transmission.

[0110] The shape curve of the hyperbolic waveguide horn 500 This can be expressed by the following equation: ,in, The radius of the horn throat (i.e., the end connected to the first loudspeaker 200) is [radius value]. It is the distance along the length of the horn, starting from the throat of the horn. These are characteristic values ​​used to control the horn expansion rate. The adjustment factor is (<1). In this way, the shape of the horn curve can change smoothly with distance.

[0111] The opening area of ​​the hyperbolic waveguide horn 500 This can be expressed by the following equation: ,in, The area of ​​the horn throat. In this way, the opening area of ​​the horn can change smoothly with distance.

[0112] For example, the installation diagram of the first loudspeaker 200 and the waveguide horn 500 can be shown as follows: Figure 11 As shown. Furthermore, when there is an angle between the orientation of the radiation port of the first loudspeaker 200 and the normal of the circumferential side plate 102, the waveguide horn 500 can be obliquely adapted, as shown in the figure. Figure 12 and Figure 13As shown, the waveguide horn 500 can thus fit better with the circumferential side plate 102 of the housing 100, achieving both aesthetics and practicality. After being modified to an oblique cut, the low-frequency response of the first speaker 200 is almost unaffected, while the mid-to-high frequency on-axis response of the first speaker 200 is smoother and the overall sensitivity is increased by approximately 2-5 dB. Figure 14 As shown. Furthermore, the first loudspeaker 200 improves the overall off-axis energy isolation (on-axis energy - off-axis 90° energy) in the mid-to-high frequency direction of the listener by 5-10 dB, such as... Figure 15 As shown.

[0113] In addition, the second speaker can also be connected to the front panel via a waveguide horn.

[0114] According to the speaker 1000 of the above embodiment, the waveguide horn 500 improves the directionality and efficiency of the sound waves radiated by the first speaker 200, ensuring that the sound waves have better focusing and transmission characteristics when radiating from the opening, increasing the energy of the sound waves propagating in the axial direction of the first speaker 200, and thus increasing the intensity of the reflected sound of the first speaker 200.

[0115] In some embodiments, the distance between the geometric center of the diaphragm of the first speaker 200 and the geometric center of the diaphragm of the second speaker 300 is less than or equal to 17 cm.

[0116] For example, the distance between the geometric center of the diaphragm of the first speaker 200 and the geometric center of the diaphragm of the second speaker 300 should be as small as possible.

[0117] According to the speaker 1000 of the above embodiment, the second speaker 300 is disposed near the first speaker 200, which can reduce the phase delay and spatial difference between the first speaker 200 and the second speaker 300, and ensure that the second speaker 300 suppresses the direct sound of the first speaker 200 more accurately.

[0118] Figure 16 A schematic flowchart illustrating an audio signal processing method according to one embodiment of this disclosure is shown. Figure 16 The method M200 shown includes steps S210 to S230. This method can be implemented by the speaker 1000 in any embodiment of this disclosure.

[0119] In step S210, the first channel audio signal is received.

[0120] In step S220, the first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient to generate the first speaker driving signal and the second speaker driving signal.

[0121] In step S230, a first speaker driving signal is provided to the first speaker and a second speaker driving signal is provided to the second speaker, so that the first speaker and the second speaker generate sound waves respectively; wherein, the sound wave generated by the first speaker that propagates directly to the listening position is at least partially canceled by the sound wave generated by the second speaker; and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled by the sound wave generated by the second speaker.

[0122] According to the audio signal processing method of this disclosure, the first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient to generate the first speaker driving signal and the second speaker driving signal, respectively. This results in the sound wave generated by the first speaker that propagates directly to the listening position being at least partially canceled by the sound wave generated by the second speaker, and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled by the sound wave generated by the second speaker. This achieves the preservation of the reflected sound of the first speaker and the suppression of the direct sound of the first speaker at the listening position, and avoids the direct sound of the first speaker weakening the sense of space created by the reflected sound of the first speaker.

[0123] Regarding step S220, as one possible implementation, it may include, for example... Figure 17 Steps S221 to S222 are shown.

[0124] In step S221, the first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient to obtain the first filtered signal and the second filtered signal.

[0125] In step S222, the first speaker driving signal and the second speaker driving signal are obtained based on the first filtered signal and the second filtered signal, respectively.

[0126] According to the audio signal processing method of the above embodiments, the first speaker driving signal and the second speaker driving signal are generated after filtering, thereby enabling precise control of the output characteristics of the first speaker and the second speaker, improving the accuracy of sound wave cancellation and the stability of the overall audio processing.

[0127] Regarding step S220, as one possible implementation, it may include, for example... Figure 18 Steps S221' to S224' are shown.

[0128] In step S221', the second channel audio signal is received, and the second channel audio signal and the first channel audio signal are audio signals of different channels.

[0129] In step S222', the first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient to obtain the first filtered signal and the second filtered signal.

[0130] In step S223', the second channel audio signal is superimposed with the second filtered signal to obtain a superimposed audio signal.

[0131] In step S224', the first speaker driving signal and the second speaker driving signal are obtained based on the first filtered signal and the superimposed signal, respectively.

[0132] According to the audio signal processing method of the above embodiment, the second channel audio signal and the second filtered signal are superimposed to generate the second speaker driving signal, so that the sound wave generated by the second speaker can both cancel the direct sound of the first speaker and express the second channel audio signal. Therefore, it is not necessary to configure an additional speaker for playing the second channel audio, saving the number of speakers used, and making the speaker compatible with playing multi-channel audio while maintaining the sense of space.

[0133] For details on the implementation process of each step in the above method, please refer to the explanation of the function and role of the corresponding structure in the speaker above, which will not be repeated here.

[0134] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., refer to specific features, structures, or characteristics described in connection with that embodiment / mode or example, which are included in at least one embodiment / mode or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0135] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0136] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this disclosure can be understood according to the specific circumstances.

[0137] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0138] This disclosure provides many different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described herein. Of course, these are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, this disclosure provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0139] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A speaker, characterized in that, include: case; The first speaker is installed inside the housing; A second speaker is installed inside the housing, the radiation port of the second speaker faces the listening position and is different from the radiation port of the first speaker, and the second speaker is disposed near the first speaker; as well as The signal processing circuit is configured to receive a first channel audio signal, filter the first channel audio signal based on a first filter coefficient and a second filter coefficient respectively, generate a first speaker driving signal and a second speaker driving signal, and provide the first speaker driving signal to the first speaker and the second speaker driving signal to the second speaker, so that the first speaker and the second speaker respectively generate sound waves. Wherein, the sound wave generated by the first speaker that propagates directly to the listening position is at least partially canceled out by the sound wave generated by the second speaker; and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled out by the sound wave generated by the second speaker.

2. The speaker according to claim 1, characterized in that, The signal processing circuit includes: A first FIR filter is configured to receive the first channel audio signal and filter the first channel audio signal based on the first filter coefficients to obtain a first filtered signal. The second FIR filter is configured to receive the first channel audio signal and filter the first channel audio signal based on the second filter coefficients to obtain the second filtered signal. The first speaker driving signal and the second speaker driving signal are obtained based on the first filtered signal and the second filtered signal, respectively.

3. The speaker according to claim 1, characterized in that, The signal processing circuit is further configured to receive a second channel audio signal, superimpose the second channel audio signal with a second filtered signal obtained by filtering the first channel audio signal based on the second filter coefficient, and generate a second speaker driving signal, wherein the second channel audio signal and the first channel audio signal are audio signals of different channels.

4. The speaker according to claim 3, characterized in that, The first filter coefficients and the second filter coefficients are determined based on the minimum variance distortionless response algorithm.

5. The speaker according to any one of claims 1 to 4, characterized in that, The first filter coefficients and the second filter coefficients are obtained through the following steps: Based on the target driving signal, the first speaker and the second speaker in the speaker box are controlled to generate sound waves respectively; At the listening position of the speaker, first transfer function information, second transfer function information, and third transfer function information are detected respectively. The first transfer function information is the ratio of the sound wave signal generated by the first speaker based on the target driving signal when it directly propagates to the listening position to the Fourier transform of the target driving signal. The second transfer function information is the ratio of the sound wave signal generated by the first speaker based on the target driving signal when it propagates to the listening position after reflection to the Fourier transform of the target driving signal. The third transfer function information is the ratio of the sound wave signal generated by the second speaker based on the target driving signal when it directly propagates to the listening position to the Fourier transform of the target driving signal. Based on the minimum variance distortionless response algorithm, the frequency domain weights of the first loudspeaker and the second loudspeaker are determined according to the first transfer function information, the second transfer function information and the third transfer function information. as well as Inverse Fourier transforms are performed on the frequency domain weights of the first speaker and the second speaker respectively to obtain the time domain weights of the first speaker and the second speaker. The time domain weights of the first speaker are used as the first filter coefficients and the time domain weights of the second speaker are used as the second filter coefficients.

6. The speaker according to claim 5, characterized in that, Based on the minimum variance distortionless response algorithm, the frequency domain weights of the first loudspeaker and the second loudspeaker are determined according to the first transfer function information, the second transfer function information, and the third transfer function information, including: Based on the first transfer function information and the third transfer function information, a loudspeaker array response vector for the direct propagation path is generated, wherein the components of the loudspeaker array response vector for the direct propagation path are the first transfer function information and the third transfer function information; The spatial covariance matrix of the direct propagation path is obtained by performing an outer product operation between the conjugate transpose of the loudspeaker array response vector of the direct propagation path and the loudspeaker array response vector of the direct propagation path. Based on the second transfer function information, a loudspeaker array response vector for the reflection propagation path is generated, wherein the components of the loudspeaker array response vector for the reflection propagation path are the second transfer function information; and Multiplying the inverse of the spatial covariance matrix of the direct propagation path with the loudspeaker array response vector of the reflection propagation path and dividing by a normalization factor yields a frequency domain weight vector. The components of the frequency domain weight vector are the frequency domain weights of the first loudspeaker and the second loudspeaker. The normalization factor is the inner product between the conjugate transpose of the loudspeaker array response vector of the reflection propagation path and the result of weighting the loudspeaker array response vector of the reflection propagation path by the spatial covariance matrix of the direct propagation path. Optionally, the housing includes a front panel and a circumferential side panel connected to the front panel, with the radiation port of the first speaker facing the circumferential side panel and the radiation port of the second speaker facing the front panel; Optionally, the circumferential side plate includes a side panel and a top panel; When the first speaker is a side surround channel speaker, the radiation port of the side surround channel speaker faces the side panel, and the first channel audio signal is a side surround channel audio signal; When the first speaker is a sky channel speaker, the radiation port of the sky channel speaker faces the top panel, and the first channel audio signal is a sky channel audio signal; Optionally, the orientation of the radiation port of the first speaker is at an angle to the normal of the circumferential side panel, and the orientation of the radiation port of the second speaker is parallel to the normal of the front panel. Optionally, the circumferential side plate is provided with an opening, and the radiation port of the first loudspeaker is connected to the opening through a waveguide horn; Optionally, the distance between the geometric center of the diaphragm of the first speaker and the geometric center of the diaphragm of the second speaker is less than or equal to 17 cm.

7. An audio signal processing method, characterized in that, The method, applied to a speaker according to any one of claims 1 to 6, comprises: Receives the first channel audio signal; The first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient, respectively, to generate a first speaker drive signal and a second speaker drive signal; and The first speaker driving signal is provided to the first speaker, and the second speaker driving signal is provided to the second speaker, so that the first speaker and the second speaker respectively generate sound waves; Wherein, the sound wave generated by the first speaker that propagates directly to the listening position is at least partially canceled out by the sound wave generated by the second speaker; and the sound wave generated by the first speaker that propagates to the listening position after reflection is not canceled out by the sound wave generated by the second speaker.

8. The audio signal processing method according to claim 7, characterized in that, The first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient respectively to generate a first speaker driving signal and a second speaker driving signal, including: The first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient, respectively, to obtain a first filtered signal and a second filtered signal; and The first speaker drive signal and the second speaker drive signal are obtained based on the first filtered signal and the second filtered signal, respectively.

9. The audio signal processing method according to claim 7, characterized in that, The first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient respectively to generate a first speaker driving signal and a second speaker driving signal, including: Receive a second channel audio signal, wherein the second channel audio signal and the first channel audio signal are audio signals from different channels; The first channel audio signal is filtered based on the first filter coefficient and the second filter coefficient respectively to obtain the first filtered signal and the second filtered signal. The second channel audio signal is superimposed with the second filtered signal to obtain a superimposed audio signal; and The first speaker driving signal and the second speaker driving signal are obtained based on the first filtered signal and the superimposed signal, respectively.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the audio signal processing method according to any one of claims 7 to 9.

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