Implementation of lumped element multimode modeling for balanced-armature receivers

Abstract

Lumped element (LE) modeling is one of the simplest and fastest tools for designing and predicting the performance of miniature speakers. Tweeters are being incorporated more frequently to extend the high-frequency range of earphones in the commercial earphone market with balanced armature (BA) receivers being commonly used as tweeters. To support this trend, it is necessary to develop LE models of BAs that are accurate at high frequencies. Developing accurate models has been challenging due to several mechanical and acoustic modes interacting at frequencies over 10 kHz. Based on the work of Sun and Hu [“Lumped element multimode modeling of balanced-armature receiver using modal analysis,” J. Vib. Acoust. 2016 Dec 1;138(6)], a multimode LE modeling method using finite element (FE) modal analysis is implemented and compared with older LE models. The simulation results are compared with experimental data for several production models of BA. The multimode LE method shows significant improvements compared to the old single-mode LE models in predicting BA receiver acoustic response, especially at frequencies above 10 kHz.