参量扬声器足近年来出现的一种新的声源。根据宽带参量阵理论的“Berktay远场解”,对参量扬声器的一种信号处理方法——DSB(Double Side Band)法的互调失真问题进行了理论与实验研究。研究发现,DSB法除了存在幅值失真、谐波失真外,还存在互调失真,且实测互调失真较理论预测的复杂。在此基础上指出,“Berktay远场解”只能在一定程度上作为参量扬声器信号处理的理论依据,寻找更为精确的自解调理论模型是解决参量扬声器信号处理问题的根本途径。
The parametric loudspeaker is a novel sound source. The sound distortion of the Double Side Band (DSB) method, which is one of the signal processing methods of the parametric loudspeaker, is investigated by theoretical derivation and experimental measurement according to the broad band parametric theory of "Berktay's Far Field Solution". The results show that intermodulation distortion exists in the DSB method, besides amplitude distortion and harmonic distortion, and the measured sound distortion is more complicated than the theoretical one. Based on this findings, it is indicated that the "Berktay's Far-Field Solution" can only be used in the qualitative analysis of the signal processing of the parametric loudspeaker to a certain extent, and the ultimate way to solve the signal processing problems of the parametric loudspeaker is to establish a more precise self-demodulation model.