Digital loudspeaker drive method and device based on quaternary code dynamic mismatch reshaping

A digital speaker, mismatch shaping technology, applied in the direction of speaker distribution signal, sensor, electrical components, etc., can solve the problem of frequency response of speaker unit, small dynamic range of input signal, temperature rise, etc.

Active Publication Date: 2013-06-12
INST OF ACOUSTICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

Among them, the digital system circuit of 1-bit Σ-Δ modulation is relatively simple to implement, but the system itself has the following defects: ①It is sensitive to clock jitter, and it is easy to introduce nonlinear distortion due to clock jitter; ②In order to maintain the modulation structure Stability, the allowable dynamic range of the input signal is small; ③ requires a high switching rate, and the power MOSFET tube will produce more nonlinear distortion components in the process of driving the speaker load for high-speed switching, and will also cause MOSFET tube heating increases, temperature rises and efficiency decreases
At present, existing literature has proposed a ternary state encoding based on "-1", "0" and "+1" and a quaternary state encoding of "-1", "0H", "0L" and "+1". The digital loudspeaker driving method, and for the "-1", "0" and "+1" tripl...

Method used

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  • Digital loudspeaker drive method and device based on quaternary code dynamic mismatch reshaping
  • Digital loudspeaker drive method and device based on quaternary code dynamic mismatch reshaping
  • Digital loudspeaker drive method and device based on quaternary code dynamic mismatch reshaping

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Embodiment 1

[0115] In this embodiment, first, design the dynamic mismatch shaper according to the traditional two-state VFMS algorithm; then, according to Figure 11 As shown, the channel data is merged, and the encoding mapping is performed; finally, the mapping encoding state is used to control the switching of the MOSFET tube of the full-bridge drive network, thereby driving the transducer load to produce sound.

[0116] Assuming that the post-transducer load driven by the full-bridge drive network is an ideal ultra-wideband load unit, when the output state of the power tube is "0" or "1", the ideal transducer load can accurately radiate these states go out. Assuming that the frequency responses of the transducer loads on the 8 digital channels are exactly the same, under this assumption, the spectrum of the 8-channel synthetic signal based on the quaternary state code dynamic mismatch shaping method obtained by simulation is as follows: Figure 13 shown by the dotted line.

[0117] ...

Embodiment 2

[0120] In this embodiment, it is assumed that the post-stage transducer load driven by the full-bridge drive network is an ideal ultra-wideband load unit, and it is assumed that when the transducer load unit is in the state of radiating "0" or "1", there is a certain Amplitude error, its error distribution obeys a Gaussian distribution with a mean value of 0 and a variance of 0.01. According to this error distribution characteristic, there is a certain frequency response difference among the loads of the 8 channels.

[0121] When the traditional ternary state code VFMS algorithm based on "+1", "0" and "-1" is used for 8-channel mismatch shaping, the spectrum of the 8-channel composite signal is as follows Figure 14 As shown in the solid line of , while adopting the quaternary code VFMS algorithm based on "+1", "0H", "0L" and "-1" proposed by the present invention, the frequency spectrum of its 8-channel composite signal is as follows Figure 14 shown by the dotted line. Comp...

Embodiment 3

[0123] In this embodiment, the digital load unit adopts the full-band loudspeaker unit with a box produced by Swans to form an 8-element linear array, wherein the DC resistance of the loudspeaker unit is 15Ω, the distance between the array elements is 12cm, and the array length is 96cm; the microphone unit adopts Audio Precision The company's AP2722 audio analyzer has a built-in microphone, and the received signal of the microphone is collected and recorded by the AP2722 audio analyzer, and analyzed by FFT to obtain the received signal spectrum.

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Abstract

The invention relates to a digital loudspeaker drive method and a device based on quaternary code dynamic mismatch reshaping. The method comprises the steps of (1) conducting input format conversion, (2) conducting multi-bit sigma to delta modulation, (3) conducting thermometer code conversion, (4) conducting dynamic mismatch reshaping processing, (5) conducting channel data combination and mapping coding, (6) controlling metal-oxide-semiconductor field effect transistor (MOSFET) pipe of a full-bridge power amplifier network to conduct opening and closing status switching, and driving a digitalized loudspeaker load to produce sound. The device comprises a sound source (1), a digital format converter (2), a multi-bit sigma to delta modulator (3), a thermometer coder (4), a dynamic mismatch reshaper (5), a channel data combiner (6), a mapping coder (7), a multi-channel digital amplifier (8) and the digitalized loudspeaker load (9). The units are sequentially connected in order. According to the digital loudspeaker drive method and the device based on quaternary code dynamic mismatch reshaping, use efficiency of an amplifier pipe and the load is improved, development periods and hardware implementation cost are saved, and good immunity is provided for frequency response deviation of digital channels.

Description

technical field [0001] The invention relates to a digital loudspeaker driving method and device based on dynamic mismatch shaping, in particular to a digital loudspeaker driving method and device based on quaternary code dynamic mismatch shaping. Background technique [0002] With the vigorous development of large-scale integrated circuits and digital technology, the inherent defects of traditional analog speaker systems in terms of power consumption, volume, weight and signal transmission, storage, processing, etc. are becoming more and more obvious. In order to overcome these defects, the speaker system's R&D is gradually developing in the direction of low power consumption, small appearance, digitization and integration, forming a new research field with the digitization of the speaker system as the core of the research. [0003] The research focus of the digital loudspeaker system includes: digital coding modulation technology, digital power drive technology and digital ...

Claims

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Application Information

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IPC IPC(8): H04R3/12H04R1/00
Inventor 蔡野锋马登永沐永生杨军
Owner INST OF ACOUSTICS CHINESE ACAD OF SCI
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