Research and Application of Rectangle Micro-Speaker for Portable Device

• Main Author: 張瑞成
• Other Authors: 黃錦煌
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/kbnn22

碩士 === 逢甲大學 === 電聲碩士學位學程 === 103 === Currently, importing simulation to electric-acoustic products design is kind of trend. It could short the lead time and reduce cost. In this thesis, build a simulation model for rectangle micro-speaker to estimate Bl(x), Km(x), frequency response and distortion. Using finite element method commercial software FEMM to simulate Bl(x) could get higher magnetic force and sensitivity. Using finite element method commercial software COMSOL to simulate Km(x) could get flat and symmetrical curves. Using lump model to simulate frequency response curve could find the optimize design of structure, Bl(x) and else. In the case, increasing height of polar piece could enhance sensitivity. To change the magnet size or level is not the only way to get higher sensitivity. Shifting the top point of diaphragm pattern from fame side to voice coil side could reduce the distortion in effective bandwidth range. To increase height of diaphragm pattern could reduce distortion below effective bandwidth range. Changing pattern from inside to outside could reduce distortion between 1/2 harmonic of F0 and 2nd harmonic of F0. By subjective listening test (Jury Test), confirmed the design of the rectangle micro-speaker have a better sound quality. Above analysis, using FEM commercial software and lump model assist in the design phase of the micro-speakers can predict the frequency response and distortion. Not only solve the design issue, but also save the time and cost.