Magnetic circuit for acoustic transducer, and speaker unit

Abstract

An object of the present invention is to provide a magnetic circuit for an acoustic transducer, the magnetic circuit enabling peeling of the surface of a member formed by compression-molding a soft magnetic composite material to be suppressed. The present invention is a magnetic circuit for an acoustic transducer, the magnetic circuit including: a yoke 151; a magnet 152; and a top plate 153, wherein the yoke 151 includes a bottom surface portion 151a and a pole piece 151b provided perpendicular to the bottom surface portion 151a, the magnet 152 and the top plate 153 are provided in that order on the bottom surface portion 151a, a magnetic gap 141 in which a voice coil 14 is disposed is formed between the pole piece 151b and the top plate 153, at least one of the pole piece 151b and the top plate 153 includes: a composite material part 154 in a position facing the magnetic gap 141; and a protective layer 155 covering at least a surface of the composite material part 154, the composite material part 154 is formed from a soft magnetic composite material, and the material of the protective layer 155 differs from the soft magnetic composite material.

Dependencies are inferred from the claim text.