Abstract: There is provided an acoustic diaphragm which includes a diaphragm base material composed of a paper article comprised of fine mica flakes, pulp fibers, and polyvinyl alcohol fibers and formed to be a multi-cellular structure; and a sheet material combined with the paper article or the diaphragm base material.

Abstract: A speaker includes a magnetic circuit forming a slit-like magnetic gap, a frame that houses and holds the magnetic circuit, a diaphragm attached to the frame so as to be capable of vibrating, a voice coil unit that is placed so as to pass through substantially the center of the magnetic gap, and has its one end coupled to the diaphragm, and a damper attached to the frame to support the other end of the voice coil unit. The voice coil unit has a planar-type coil bobbin section, and a voice coil section having a coil member wound in a planar track shape and disposed so as to extend through the coil bobbin section from one side to the other side and from the other side to the one side.

Abstract: To propose a speaker unit and a speaker apparatus enabling to improve the strength of a voice coil bobbin and sound output in high quality with a simple structure, there are provided that a magnetic circuit forming a magnetic gap in slit form, a frame for storing and holding the magnetic circuit, a diaphragm attached to be vibratable to the frame, a flat-type voice coil bobbin disposed so as to pass through the almost center of the magnetic gap, in that its one end is combined with the diaphragm, a voice coil is adhered to its surface, and convex and concave parts for improving the strength of the diaphragm in the vibrating direction are formed on the surface, and a damper attached to the frame to support the other end of the flat-type voice coil bobbin.

Abstract: A speaker diaphragm includes a thermoplastic resin having a three-layer structure. The three-layer structure includes a polyester film as a base material of the three-layer structure, a polyimide-based resin layer as a top layer of the three-layer structure, and another polyimide-based resin layer as a bottom layer of the three-layer structure.

Abstract: A loudspeaker damper including: an outer damper; and an inner damper; wherein the outer damper and the inner damper configured to damp a vibrating portion relative to a fixed portion of a loudspeaker, wherein the outer damper supports the outer periphery of a voice coil of the vibrating portion, and supports the outer periphery of the voice coil relative to the fixed portion, wherein the inner damper supports the inner periphery of the voice coil, and supports the inner periphery of the voice coil relative to the fixed portion.

Abstract: There is provided an acoustic diaphragm which includes a diaphragm base material composed of a paper article comprised of fine mica flakes, pulp fibers, and polyvinyl alcohol fibers and formed to be a multi-cellular structure; and a sheet material combined with the paper article or the diaphragm base material.