PROJECT TITLE :

Effect of nonlinear stiffness on the total harmonic distortion and sound pressure level of a circular miniature loudspeaker-experiments and simulations

ABSTRACT :

This paper reports our study on the nonlinear stiffness of some diaphragm designs used for miniature loudspeakers. For this study, the sample diaphragms were experimented for his or her stiffness curves using the laser vibrometry. Additionally, the stiffness curves were conjointly obtained using finite element analysis (FEA). For calculating total harmonic distortion (THD), the electroacoustic system is modeled using the equivalentcircuit analogy. As a result of solving the coupled system of standard differential equations by the Runge-Kutta method, THD of 3 sample styles, characterised by different track patterns, were calculated and plotted as a operate of frequency. The specimens were tested in a very commonplace anechoic chamber for recording THD. Additionally, the sound pressure level (SPL) curves of these specimens were additionally recorded for comparison. It seems that, despite no vital SPL difference, diaphragms with completely different track patterns shall, thence, result in substantial variations of THD. The consistence of our simulations with the measured THD has promised the feasibility of simulating THD by FEA for optimizing the design of track patterns for diaphragm.