Development of Hi-Fi microspeakers with a woofer and a tweeter used for mobile phones

For mobile phones, high performance microspeakers with broader frequency range are essential parts to realize various multimedia functions such as MP3 playback, speaker phones, and 64 poly-harmonic melody. Noting that the operating frequency range of conventional microspeakers ranges from $900Hzto10kHz$⁠, that of $400Hzto10kHz$ for hi-fi microspeakers is required to meet customer demand in a multimedia era. One possible way of achieving this is to integrate two-way microspeakers (woofer and tweeter) within one device sharing not only magnetic circuit but also vibration space. Noting that the characteristics of the microspeakers are a coupled phenomenon of electromagnetic, mechanical and acoustic system, a systematic analysis must be implemented to fully consider the coupling effects. In this article, a hi-fi microspeaker with a woofer and a tweeter is introduced and the sound pressure level is also calculated and compared with the experimental results. Results show the development can be a successful alternative for the high performance microspeakers of a multimedia era.