ELECTROACOUSTIC TRANSDUCER

摘要

Provided is a small electrodynamic electroacoustic transducer by which a reproduction band can be expanded, the maximum sound pressure in the reproduction band can be set high, and the transducer can be made thinner. An edge portion (12B) of a diaphragm (12) is composed of a three-layer structure polymer material layer (12U, 12L, 12M). Both of the upper layer (12U) and the lower layer (12L) are polyether imide, and are formed to have a substantially same thickness so that the edge portion (12B) becomes superior in terms of durability and resistance to the environment. Thereby, in order that the edge portion (12B) has a lower modulus of elasticity, the edge portion (12B) can become thin and the lowest resonant frequency can be lowered. Further, the intermediate layer (12M) is an acrylic adhesive and is thicker than the upper layer (12U) and the lower layer (12L) so that the loss tangent of the edge portion (12B) can be made larger to previously prevent the occurrence of overamplitude at the lowest resonant frequency. Thereby, the maximum sound pressure in the reproduction band can be set high, and the transducer can be made thinner.