A resonant efficiency acoustic back wall speaker

Abstract

The application relates to a resonance effect echo wall speaker and relates to the technical field of echo wall speakers. The existing echo wall speaker has the problems of poor frequency response, insufficient bass performance and the like in the low frequency band below 150Hz. The echo wall speaker comprises a box body, a front loudspeaker, a surrounding loudspeaker and a control unit arranged in the box body; at least one tabletop resonator is arranged at the bottom of the box body; the control unit comprises a digital signal processor and a vibration control operational amplifier; the digital signal processor comprises an audio event detector based on the event detection algorithm of data block differentiation; the low-pass filtered data of the digital signal processor is used as the input data of the audio event detector, the input data is recursively differentiated by the audio event detector, the gradient is calculated, when the gradient meets the preset threshold value, the tabletop resonator is triggered to start vibration, and through the sound hearing and tabletop vibration tactile experience, the game player can be provided with unique and immersive game experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of echo wall sound box. BACKGROUND

[0002] Echo wall sound box is usually composed of multiple speaker units, including left and right stereo speakers, center speakers and built-in bass units. The virtual surround sound technology (such as Dolby Atmos, DTS:X, etc.) can simulate the surround effect of stereo sound, so that users can have a more immersive experience when watching TV, movies or playing games.

[0003] With the increasing demand of today's game players for auditory and tactile experience of games, the existing echo wall sound box cannot meet the requirements of auditory and tactile experience, such as: the speaker usually has poor frequency response in the low frequency band below 150Hz, and the bass performance is insufficient. SUMMARY

[0004] In summary, the purpose of the present application is to solve the problem of the existing echo wall sound box that the speaker has poor frequency response in the low frequency band below 150Hz and insufficient bass performance, and to propose a resonance effect echo wall sound box.

[0005] To solve the technical problems proposed in the present application, the technical scheme adopted is:

[0006] A resonance effect echo wall sound box, comprising a bar-shaped box, a front speaker, a surround speaker and a control unit are arranged in the box; characterized in that: the bottom of the box is provided with at least one desktop resonator supporting the box; the control unit comprises a digital signal processor and a vibration control operational amplifier; the digital signal processor contains an audio event detector based on event detection algorithm of data block differentiation; the digital signal processor uses an IIR filter to perform low-pass filtering on the audio input signal, and the low-pass filtered data is used as the input data of the audio event detector; the input data is recursively differentiated by the audio event detector, and the gradient is calculated; when the gradient meets the preset threshold, a trigger signal is output, triggering the desktop resonator to start vibrating, and simultaneously outputting the current frame average sound pressure and the corresponding low frequency band spectrum power distribution vector as the input parameters of the amplitude and vibration frequency of the vibration control operational amplifier, and the vibration control operational amplifier executes the vibration control of the desktop resonator.

[0007] The technical scheme further limiting the present application includes:

[0008] The digital signal processor further comprises a dynamic bass enhancer; the dynamic bass enhancer adopts a dynamic bass enhancement algorithm based on an equal loudness curve to compensate the low frequency part of the audio input signal in frequency response, improve the bass performance, and realize the balance on the whole frequency band of 20Hz-20KHz.

[0009] The compensation vector of the low frequency part of the audio signal below 100Hz in frequency response compensation is σ(k,j)=h0(k,j)-h(k,j); wherein,

[0010] h0(k,j) is an equal loudness frequency response vector corresponding to a certain loudness level;

[0011] h(k,j) is a frequency response vector corresponding to a certain loudness level under real-time state;

[0012] k is a loudness level,

[0013] j is a frequency point index; and: j*r f <100Hz, wherein r f is the frequency resolution.

[0014] The dynamic bass enhancer compensates the frequency response and outputs the final audio signal X OUT(m,k) to the front loudspeaker and the surround loudspeaker. IN(m,k) , wherein:

[0015] X IN(m,k) is the frequency domain representation of the input signal,

[0016] X OUT(m,k) is the frequency domain representation of the output signal,

[0017] m is a time sequence, and k is a frequency point sequence;

[0018] The inverse Fourier transform reconstructs the time domain signal as:

[0019] x_out(m,k)=ifft(X OUT(m,k) ).

[0020] The cabinet is an arc structure, the front loudspeaker is arranged inside the front side wall of the cabinet, left and right ends of the cabinet are respectively provided with left and right acoustic cavities, and one surround loudspeaker is arranged in each of the left and right acoustic cavities.

[0021] The time domain difference equation vector of the IIR filter for low-pass filtering the audio input signal is:

[0022] A T y=B T x

[0023] Wherein:

[0024] Vector x∈C 3X1 is the time domain input sequence of a frame data at n moment;

[0025] Vector y∈C 3X1 is the time domain output sequence after filtering at n moment;

[0026] Vector A∈C 3X1 , B∈C 3X1 is the coefficient vector of IIR filter.

[0027] The step of the audio event detector to recursively differentiate the input data is: continuously cache multiple frames of data at a certain sampling rate, each frame has N sampling points; sum each data block element and calculate the average value s_e, the process is as follows:

[0028]

[0029]

[0030] …

[0031]

[0032]

[0033] When calculating the gradient, the gradient threshold g_td is determined by the empirical value, and the gradient g of the current data block is calculated:

[0034] g=e0 / s_e

[0035] If:

[0036] g>g_td,

[0037] Then:

[0038] T=1;

[0039] Otherwise:

[0040] T=0;

[0041] T=1, indicating that the output trigger signal triggers the desktop resonator to start vibrating;

[0042] T=0, indicating that the desktop resonator remains silent;

[0043] Synchronously output the current frame average sound pressure, and the corresponding low frequency band spectrum power distribution vector is calculated by short time Fourier transform (stft) to calculate the power spectrum of the current data block x(n):

[0044] X(n)=stft(x(n)),

[0045]

[0046] Wherein:

[0047] n, represents n moment;

[0048] The T, e0, X(n) parameters are fed to the vibration control operation amplifier as the amplitude and vibration frequency input parameters of the vibration control operation amplifier; the above steps are repeated through iterative regression to calculate the T, e0, X(n) corresponding to each frame of data.

[0049] The front loudspeakers are two, which are symmetrically arranged in the inside of the front side wall of the cabinet, and one tabletop resonator is arranged on the bottom of the cabinet near the center on the side of the two loudspeakers.

[0050] The bottom of the tabletop resonator is sleeved with a silica gel buffer pad.

[0051] The digital signal processor is connected with the MCU, and the vibration switch button is further connected to the MCU.

[0052] The beneficial effects of the present application are: the present application uses an IIR filter to perform low-pass filtering near 100Hz, and the data after low-pass filtering is used as the input data of the subsequent algorithm; recursive differentiation is performed to obtain the gradient. When the gradient meets a certain threshold, a trigger signal T is output, triggering the vibration unit to start vibrating. The current frame average sound pressure E and the corresponding low-frequency band spectral power distribution vector are synchronously output as the input parameters for controlling the vibration frequency and amplitude of the vibration unit. Using the differential algorithm, the influence of the volume size on the audio event detection result can be effectively shielded, that is, the trigger signal T is only related to the signal itself and is independent of the gain applied in the audio processing process, thereby improving the robustness of the algorithm and better realizing 4D immersive experience. At the same time, the synchronous extraction of the average sound pressure E and the spectral power distribution vector can make more flexible control on the vibration frequency and amplitude of the vibration unit and other multi-dimensions. The present application provides a unique and immersive game experience for game players through sound hearing and tabletop vibration tactile experience. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 It is a schematic diagram of the three-dimensional structure of the present application;

[0054] Figure 2 It is a schematic diagram of the decomposition structure of the resonance effect echo wall speaker of the present application;

[0055] Figure 3 It is a schematic diagram of the function implementation principle of the present application. DETAILED DESCRIPTION

[0056] The structure of the present application will be further described in combination with the drawings and the preferred specific embodiments of the present application.

[0057] Reference Figure 1 and Figure 2 As shown in the figure, the present invention discloses a resonant soundbar speaker, including a strip-shaped enclosure 1, in which a front speaker 2, surround speakers 3, and a control unit are arranged; for aesthetic purposes and sound hole protection, the outer surface of the enclosure 1 is also provided with a fabric layer; the present invention provides at least one desktop resonator 4 at the bottom of the enclosure 1, which supports the enclosure 1; traditional desktop resonators 4 are generally used in resonant speakers, and the difference from the speaker structure is that the desktop resonator 4 itself does not have a diaphragm, but is driven by an audio signal to vibrate a medium in contact with a hard object to produce sound, such as a wooden desktop, which produces a noticeable bass vibration. Since the material of the vibrating medium in contact with the resonant speaker has a significant impact on the sound quality, it cannot currently replace the speaker enclosure that produces sound; the purpose of adding a desktop resonator 4 to the soundbar speaker of the present invention is not to simply superimpose technology on the speaker enclosure structure, nor to replace technology, but mainly to solve the problem that the speaker of the soundbar speaker has poor frequency response and insufficient bass performance in the low frequency range below 150Hz, in order to enhance the auditory and tactile experience of gamers.

[0058] like Figure 3 As shown, to achieve the above objectives, the control unit includes a digital signal processor (DSP) and a vibration control operational amplifier (AMP). The DSP contains an audio event detector (BBD) based on a data block differentiation event detection algorithm. The DSP uses an IIR filter to perform low-pass filtering on the externally input audio input signal S or the audio input signal S generated by the local audio device. The low-pass filtered data is used as the input data for the audio event detector (BBD). The BBD recursively differentiates the input data to calculate its gradient. When the gradient meets a preset threshold, it outputs a trigger signal T to trigger the desktop resonator 4 to start vibrating. The BBD also synchronously outputs the current frame average sound pressure level E and the corresponding low-frequency band spectral power distribution vector X as input parameters for the amplitude and vibration frequency of the vibration control operational amplifier (AMP). The vibration control operational amplifier (AMP) then performs vibration control on the desktop resonator 4. The audio event detector BBD of this invention uses a differential algorithm, which can effectively shield the influence of volume on the audio event detection results. That is, its trigger signal T is only related to the signal itself and is independent of the gain applied during audio processing, improving the robustness of the algorithm and achieving a better 4D immersive sound experience. Simultaneously, the synchronously extracted current frame average sound pressure level E and spectral power distribution vector X allow for more flexible control over the vibration frequency and amplitude of the desktop resonator 4 in multiple dimensions.

[0059] IIR filters, also known as recursive filters with feedback, are used in the audio event detector BBD because the extracted parameters are independent of phase. Compared to FIR filters, IIR filters have a lower order and lower complexity. The time-domain difference equation vector form for low-pass filtering of the audio input signal using an IIR filter is:

[0060] A T y = B T x

[0061] in:

[0062] Vector x∈C 3X1 Given the time-domain input sequence of a frame of data at time n;

[0063] Vector y∈C 3X1 The time-domain output sequence after filtering at time n;

[0064] Vector A∈C 3X1 B∈C 3X1 This is the coefficient vector of the IIR filter.

[0065] The audio event detector BBD continuously buffers multiple frames of data at a certain sampling rate, with N sampling points per frame. The steps for recursively differentiating the input data are as follows: For the continuously buffered multiple frames of data at a certain sampling rate, with N sampling points per frame; sum the elements of each data block and calculate the average value s_e, as follows:

[0066]

[0067]

[0068] ...

[0069]

[0070]

[0071] When calculating its gradient, the gradient threshold g_td is determined by empirical values, and the gradient g of the current data block is calculated as follows:

[0072] g = e0 / s_e

[0073] if:

[0074] g>g_td,

[0075] Then we have:

[0076] T = 1;

[0077] otherwise:

[0078] T = 0;

[0079] When T=1, it indicates that a trigger signal is output, triggering the desktop resonator to start vibrating;

[0080] When T=0, it means that the desktop resonator remains silent;

[0081] The average sound pressure level of the current frame is output synchronously, and the power distribution vector of the corresponding low-frequency band is calculated using the short-time Fourier transform (STFT) to obtain the power spectrum of the current data block x(n).

[0082] X(n) = stft(x(n)),

[0083]

[0084] in:

[0085] n represents time n;

[0086] The parameters T,e0,X(n) are fed together into the vibration control operational amplifier as input parameters for the amplitude and vibration frequency of the vibration control operational amplifier. Through iterative regression, the above steps are repeated to calculate T,e0,X(n) for each frame of data.

[0087] The digital signal processor described in this invention also includes a dynamic bass enhancer (DBB). The DBB employs a dynamic bass enhancement algorithm based on equal loudness curves (with a 1kHz frequency point as a reference) to compensate for the frequency response of the low-frequency part of the audio input signal. This not only improves bass performance and achieves a balanced listening experience across the entire frequency range of 20Hz to 20kHz, but also reduces power loss.

[0088] The low-frequency audio signal, in the frequency band below 100Hz, has a compensation vector σ(k,j) = h0(k,j) - h(k,j); where,

[0089] h0(k,j) is the equal loudness frequency response vector corresponding to a certain loudness level;

[0090] h(k,j) is the frequency response vector at a certain loudness level in real time.

[0091] k is the loudness level.

[0092] j is the frequency point index; and: j*r f <100Hz, where r f This refers to the frequency resolution.

[0093] The dynamic bass enhancer, after frequency response compensation, outputs the final audio signal X to the front speaker and surround speakers. OUT(m,k) =X IN(m,k) σ(k), where:

[0094] X IN(m,k) , represents the frequency domain of the input signal.

[0095] X OUT(m,k) , which is the frequency domain representation of the output signal.

[0096] m is the time series, and k is the frequency point series;

[0097] Reconstructing the signal into the time domain using the inverse Fourier transform:

[0098] x_out(m,k)=ifft(X OUT(m,k) )).

[0099] like Figure 1 As shown, in specific implementation, the appearance design of the present invention is an arc shape that approximates a straight or curved display screen, with a slender shape that can be perfectly integrated with any gaming device. Figure 1 Taking the arc-shaped structure of the enclosure 1 as an example, the front speaker 2 is located inside the front side wall of the enclosure; the left and right ends of the enclosure 1 are respectively provided with a left acoustic cavity and a right acoustic cavity, and a surround speaker is provided in each of the left and right acoustic cavities. A preferred embodiment is that there are two front speakers, symmetrically located inside the front side wall of the enclosure, and a desktop resonator 4 is provided at the bottom of the enclosure on the side of the two speakers closest to the center. A silicone buffer pad 5 is fitted to the bottom of each desktop resonator. In specific implementation, the digital signal processor (DSP) can perform power-on / off, reset, and other operations based on a control signal C from an MCU.

[0100] This invention utilizes the resonance effect of a flat surface to generate sound effects, bringing users an unprecedented auditory and tactile experience, and effectively meeting the demands of today's gamers for a realistic 4D gaming experience. It employs a specially designed desktop resonator 4 to produce more vivid and realistic sound effects and an immersive gaming experience, enabling users to achieve a truly immersive gaming experience.

[0101] This invention interacts with a hard surface (such as a table or box) placed upon it, generating low-frequency vibrations and transmitting these vibrations to the acoustic cavity to enhance the 4D effect of sound and vibration. Within this scope, the acoustic cavity and desktop resonator 4 can be connected wirelessly or wired to an audio source device, such as a television, game console, or mobile device. The desktop resonator 4 can be selected as a vibration device via an electromagnetic exciter or any excitation device such as an air compression sensor or a piezoelectric ceramic sensor. The desktop resonator 4 is mounted on the bottom or side of the enclosure 1 to transmit vibrations to the desktop or placement surface. The desktop resonator 4 is fixed to the table by suction cups or silicone cushioning pads to ensure stability and provide good contact and effective conduction. A vibration control algorithm is implemented using a microcontroller or digital signal processor (DSP) and amplifiers, adjusting the vibration effect by modifying current, voltage, or frequency. Audio event detectors, algorithms, and filters are added to the DSP to acquire and extract vibration-related signals. Filtering and signal processing techniques preserve the frequency and amplitude range closely related to the vibration effect while suppressing irrelevant noise and signal components. The vibration effect is enhanced by signal amplifiers or amplification circuits. Based on user needs and the characteristics of the input signal, the amplification level and enhancement effect are adjusted to provide a more noticeable and immersive vibration experience. To allow users to turn off the desktop resonator 4 as needed, the MCU of this invention is connected to an independent vibration switch button, or the remote control has an independent vibration switch button. When the user does not need vibration, the vibration can be turned off independently to achieve a smoother playback effect during video playback.

Claims

1. A resonant soundbar, comprising a strip-shaped enclosure, wherein a front speaker, surround speakers, and a control unit are disposed within the enclosure; characterized in that: The bottom of the enclosure is equipped with at least one desktop resonator, which supports the enclosure. The control unit includes a digital signal processor and a vibration control operational amplifier. The digital signal processor contains an audio event detector based on an event detection algorithm using data block differentiation. The digital signal processor uses an IIR filter to perform low-pass filtering on the audio input signal. The low-pass filtered data is used as the input data for the audio event detector. The audio event detector recursively differentiates the input data to calculate its gradient. When the gradient meets a preset threshold, it outputs a trigger signal to trigger the desktop resonator to start vibrating. Simultaneously, it outputs the average sound pressure level of the current frame and the spectral power distribution vector of the corresponding low-frequency band, which are used as input parameters for the amplitude and vibration frequency of the vibration control operational amplifier. The vibration control operational amplifier then performs vibration control on the desktop resonator.

2. The resonant effect soundbar speaker according to claim 1, characterized in that: The digital signal processor also includes a dynamic bass enhancer; the dynamic bass enhancer uses a dynamic bass enhancement algorithm based on equal loudness curves to compensate for the frequency response of the low-frequency part of the audio input signal, improve bass performance, and achieve a balanced listening experience across the entire frequency range of 20Hz to 20KHz.

3. A resonant soundbar according to claim 2, characterized in that: The compensation vector for frequency response compensation in the low-frequency audio signal band below 100Hz. ;in, , is the frequency response vector of equal loudness at a certain loudness level; , is the frequency response vector at a certain loudness level in real time; , is the loudness level, , is the frequency point index; and: ,in This refers to the frequency resolution.

4. A resonant soundbar according to claim 3, characterized in that: The dynamic bass enhancer, after frequency response compensation, outputs the final audio signal to the front speaker and surround speaker. ( ) ,in: , represents the frequency domain of the input signal. , which is the frequency domain representation of the output signal. , is a time series. , is a frequency point sequence; Reconstructing the signal into the time domain using the inverse Fourier transform: 。 5. A resonant soundbar according to claim 1, characterized in that: The enclosure has an arc-shaped structure, with the front speaker located inside the front side wall of the enclosure; the left and right ends of the enclosure are respectively provided with a left acoustic cavity and a right acoustic cavity, and a surround speaker is provided in each of the left and right acoustic cavities.

6. A resonant soundbar according to claim 1, characterized in that: The time-domain difference equation vector form for low-pass filtering of audio input signals by an IIR filter is: in: vector Given the time-domain input sequence of a frame of data at time n; vector The time-domain output sequence after filtering at time n; vector , This is the coefficient vector of the IIR filter.

7. A resonant soundbar according to claim 6, characterized in that: The audio event detector performs recursive differentiation on the input data as follows: it continuously buffers multiple frames of data at a certain sampling rate, with N sampling points per frame; Sum the elements of each data block and calculate the average. The process is as follows: ； ； …… ； ； When calculating its gradient, the gradient threshold is determined by empirical values. Find the gradient of the current data block. : if: , Then we have: ； otherwise: ； When the signal is triggered, it indicates that a trigger signal is output, which triggers the desktop resonator to start vibrating; When this time, it indicates that the desktop resonator remains silent; The average sound pressure level of the current frame and the corresponding low-frequency spectral power distribution vector are output synchronously and calculated using the Short Time Fourier Transform (STFT) for the current data block. Power spectrum: ， ; in: ,express time; T, , The parameters are fed together into the vibration control operational amplifier as input parameters for the amplifier's amplitude and vibration frequency; through iterative regression, the above steps are repeated to calculate T for each frame of data. , .

8. A resonant soundbar according to claim 5, characterized in that: The front speakers are two in number, symmetrically located inside the front side wall of the enclosure. A desktop resonator is located at the bottom of the enclosure on the side of the two speakers closest to the center.

9. A resonant soundbar according to claim 8, characterized in that: The bottom of the desktop resonator is fitted with a silicone cushioning pad.

10. A resonant soundbar according to claim 1, characterized in that: The digital signal processor is connected to an MCU, and the MCU is also connected to a vibration switch button.

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