Design and Analysis of a 2-Way Microspeaker with Separated Dual Coils for Improved Acoustic Performance

The purpose of this study is to determine the optimal microspeaker design for increasing low and mid- frequency sound pressure level (SPL) performance. This is because recent changes in the shape of smartwatches have allowed for the use of larger microspeakers, which can improve acoustic performance. This study aims to determine the optimal microspeaker design for increasing the low- and mid-frequency sound pressure level (SPL) performance based on three new microspeaker designs. The prototype has a single-coil design, whereas the three new types are dual-coil designs with separate woofer (WF) and tweeter (TW) units. This study identified the optimal design by comparing all types of SPL using an electromagnetic–mechanical– acoustic (E-M-A) coupling analysis method. According to the analysis results, Type 2, with a 7:3 WF-to-TW size ratio, significantly improved the SPL in the mid-frequency range, with a small increase in SPL in the low- frequency range. Consequently, a Type 2 sample was fabricated to validate the analysis results. The experimental results confirmed the improved SPL performance and validated the simulation result.