低频电动扬声器非线性特性分析的新方法  

A Novel Method for Analysis of Electrodynamic Loudspeaker Nonlinearities

作　　者：黄海[1] 

机构地区：[1]浙江大学仪器科学与工程学系,杭州310027

出　　处：《仪器仪表学报》2005年第5期464-468,共5页Chinese Journal of Scientific Instrument

基　　金：中国-丹麦国际合作(6NPP99);DANIDA资助项目。

摘　　要：采用经验模式分解(EMD)提取信号的内禀模态函数(IMFs),并用Hilbert变换计算其瞬时频率的变化来刻划扬声器位移波形的非线性失真。实际的扬声器实验分析表明,该方法克服了用传统傅立叶谐波能量变化来表示非线性失真的局限,揭示了波内频率调制现象是造成波形失真的根本原因,并给出了具有明确物理意义的解释,对扬声器非线性特性的改进和补偿提供了一个新的思路。The empirical mode decomposition (EMD) is applied to decompose the loudspeaker displacement signals into the intrinsic mode function (IMF). The change of the instantaneous frequency which is found using the Hilbert transform is used to characterise the nonlinear distortion of the displacement wave profile in loudspeakers. With the analysis of the nonlinearities of the practical loudspeaker in an experiment, the results show that the new method provides more effectively the ability to analyzing the loudspeaker nonlinear distortion than the conventional harmonics demonstrated by Fourier transform. And it describes the intrawave frequency modulation as the basic cause of wave profile deformation, which provides a clear physical interpretation of the nonlinearities of loudspeakers. The results will be useful and helpful for compensating for the nonlinearities of loudspeakers and improving the quality of sound reproduction by loudspeakers.

关 键 词：扬声器 特性分析 HILBERT变换 非线性失真 电动 低频 经验模式分解 非线性特性 模态函数 瞬时频率 能量变化 波形失真 频率调制 物理意义 分析表 傅立叶 信号 

分 类 号：TN643[电子电信—电路与系统] TN911.72