Parametric Analysis on the Geometry of Magnetic System for Subwoofer with FEMM

Abstract

The aim of this study is to investigate the distributions of magnetic flux and the variations in B curve for a novel design of loudspeaker magnetic system. Two different geometries, simulated with commercial finite element software-(FEMM) are presented, as well as an optimized design for the geometry of magnetic system. Results showed that changes in the inner side geometry obviously influence the distributions of magnetic field. In addition, the maximal magnetic force shifts to the position of lowest cross-sectional area. Meanwhile, B curve not only reduces the B level, but also loses the original uniformity in the air gap. Thus, the distortion caused from magnetic system will increase. Based on the original design, the new design not only maintains the flat B curve, but also saves on the amount of material of required for the magnetic system by around 31 %.