Abstract
A piezoelectric speaker has some strong points compared with a dynamic speaker. It is easily made small and light due to its simple structure. Also, it is excellent in sound reproduction in the middle and higher frequency ranges. But, the sound pressure level in the lower frequency range is poor because of the amplitude of vibration being small. Up to now a great effort has been made to improve the performance of the piezoelectric speaker, but no definite solution has been found yet. In this paper, the vibration and acoustic characteristics of piezoelectric vibrator unit with conical shell structure are investigated through F.E.M. and B.E.M. analyses and experiments. Based on the investigations, a new cone type piezoelectric speaker system is designed and manufactured, and its characteristics are discussed.
