A flat piezoelectric polymer film loudspeaker as a multi-resonance system

Abstract

A flat diaphragm full-range loudspeaker utilizing a piezoelectric polymer is described. This loudspeaker is characterized by an excellently simple constitution and multiresonance response characteristics. Since the fundamental resonant frequency of a loudspeaker should be as low as possible, it is convenient to utilize the flexural vibration of a bimorph diaphragm. The input-output relation of a bimorph diaphragm radiator in a multi-resonance frequency region is studied theoretically, and the formula for estimating output sound pressure level for the resonant peak is given. This is also examined experimentally.