Analysis of acoustic characteristics according to design parameter of diaphragm

The recent cellular phones provide various functions such as satellite TV receiver, motion picture player and MP3 player. For these multimedia effects, the acoustic quality through the microspeaker is important. Thus, the functions of microspeakers are included in the preference index of the cellular phones and more powerful and high-performance microspeakers are required. A typical microspeaker is composed of magnetic circuit, voice coil, and diaphragm. Among these components, diaphragm is closely related to acoustic characteristics. Acoustic performance of the microspeaker is evaluated by frequency range and sound pressure level (SPL). In case of microspeakers, it is hard to have good performance in lower frequency region due to size. The microspeaker whose first resonance is low can make high SPL in lower frequency region. Also, SPL in higher frequency region is hardly affected by the first resonance. Therefore, in this paper, the first resonance frequency is optimized in order to investigate acoustic performance in lower frequency region as the design parameters of diaphragm are varied. A performance evaluation for each setting of parameters is simulated using finite element method (FEM). The simulated result of the proposed analysis is also compared with the experimental.