This electroacoustic transducer has a diaphragm and a magnetic circuit part. The magnetic circuit part includes a permanent magnet, a pole piece that is magnetically connected to one surface of the permanent magnet in the thickness direction, and a yoke body that includes a bottom portion, and a peripheral wall portion and that is magnetically connected to the other surface of the permanent magnet in the thickness direction on the bottom portion. At least one of the pole piece and the bottom portion of the yoke body is a laminate in which a plurality of magnetic metal plates are stacked in the thickness direction of the permanent magnet with electrical insulation between each plate.

A transducer including a driven element and a magnet assembly. The magnet assembly is coupled to the driven element and includes a first and a second magnet, and a ferrous member. Each of the magnets have a first and second magnetic pole. The first magnetic pole of the first magnet and the first magnetic pole of the second magnet being proximate to each other and facing each other thereby defining a first magnetic zone therebetween, the first magnetic poles being similar, and the second magnetic poles being similar. The ferrous member couples a substantial amount of the magnetic field emanating from the second magnetic poles and directing the substantial amount of the magnetic field to a gap between the ferrous member and the first magnetic zone.

A transducer including a driven element and a magnet assembly. The magnet assembly is coupled to the driven element and includes a first, second and third magnet. Each of the magnets have a first and second magnetic pole. The first magnetic pole of the first magnet and the first magnetic pole of the second magnet being proximate to each other and facing each other thereby defining a magnetic zone therebetween. The second magnetic pole of the third magnet being magnetically proximate to said magnetic zone. The first magnetic poles all having the same polarity, and the second magnetic poles all having the same polarity.

The invention relates to a cap (1) for an electro-acoustic transducer (2), which cap (1) comprises a first portion (3) having a form matching in shape and dimensions at least a top part of a magnetic center pole piece (4) of the transducer (2) and an opening (5) for receiving said magnetic center pole piece (4), wherein the first portion (3) includes at least one recess (6) with reduced material thickness on a lateral face (7) of the first portion (3). Also, the invention relates to: (i) a method (100) of manufacturing a capped center pole piece for an electro-acoustic transducer (2); (ii) a capped center pole piece for an electro-acoustic transducer (2); and (iii) an electro-acoustic transducer (2) comprising the cap (1) or the capped center pole piece.

A transducer including a driven element and a magnet assembly. The magnet assembly is coupled to the driven element and includes a first, second and third magnet. Each of the magnets have a first and second magnetic pole. The first magnetic pole of the first magnet and the first magnetic pole of the second magnet being proximate to each other and facing each other thereby defining a magnetic zone therebetween. The second magnetic pole of the third magnet being magnetically proximate to said magnetic zone. The first magnetic poles all having the same polarity, and the second magnetic poles all having the same polarity.

A transducer including a driven element and a magnet assembly. The magnet assembly is coupled to the driven element and includes a first and a second magnet, and a ferrous member. Each of the magnets have a first and second magnetic pole. The first magnetic pole of the first magnet and the first magnetic pole of the second magnet being proximate to each other and facing each other thereby defining a first magnetic zone therebetween, the first magnetic poles being similar, and the second magnetic poles being similar. The ferrous member couples a substantial amount of the magnetic field emanating from the second magnetic poles and directing the substantial amount of the magnetic field to a gap between the ferrous member and the first magnetic zone.

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.