Method and device for balancing frequency response of off-line iterative sound playback system

Abstract

The invention discloses a method and a device for balancing frequency response of an off-line iterative sound playback system. The method comprises the following steps of: (1) acquiring a pulse response sequence of a system to be balanced by using a measuring instrument; (2) acquiring feedback signals by selecting noise signals and utilizing the convolution of the noise signals and the pulse response sequence; (3) sequentially estimating parameters of various levels of balancers by using gradually iterative least squares criterion according to the noise signals and the feedback signals; (4) cascading the various levels of balancers to form a synthesized balancer; and (5) updating coefficients of a finite impulse response (FIR) filter by using parameters of the synthesized balancer to finish system frequency response balancing. The device comprises a sound source, a digital signal processor, a power amplifier and a loudspeaker which are sequentially connected with one another. The response balancing capacity of the balancers can be obviously improved by increasing the number of the cascaded balancers; the balancing task of complex calculation can be processed conveniently in an off-line estimation mode; and moreover, the manufacturing cost for the hardware of the balancers is saved.

Description

technical field [0001] The invention relates to a frequency response equalization method and device of a sound playback system, in particular to a method and device for off-line iterative frequency response equalization of a sound playback system. Background technique [0002] In recent years, with the rapid development of large-scale integrated circuits and digital signal processing technology, the problem of sound playback system response balance based on digital signal processing technology has gradually attracted the attention of many research institutions and enterprises at home and abroad, and several companies Launched several acoustic products with responsive equalization. Dirac, a subsidiary of Uppsala University, launched the Dirac HD Sound technology to solve the peak-to-valley point equalization of the frequency response curve of the speaker unit in a free field environment, and also launched the Dirac Live technology to solve the room The peak-to-valley point e...

AI Technical Summary

Problems solved by technology

The parameter estimation process of these methods all rely on the least mean square error (Least Mean Squares—LMS) algorithm or a single estimate of the linear predictive coding (LPC) algorithm to calculate the parameters of the equalizer. There is still a certain degree of deviation between the obtained inverse filter parameters and the ideal inverse filter parameters, and these deviations will cause the frequency response curve of the equalized sound playback system to still have obvious peak-to-valley fluctuations in some frequency bands , has not yet achieved the ideal flat frequency response

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