Patent ID: 8335339

Claim:
A speaker unit comprising: a magnetic circuit forming a magnetic gap in slit form; a frame for holding said magnetic circuit; a diaphragm attached to said frame; a flat-type voice coil bobbin disposed so as to pass through an almost center of said magnetic gap, and such that a one end of said flat-type voice coil bobbin is in contact with said diaphragm, wherein the flat-type voice coil bobbin comprises: a central convex part at the almost center of the flat-type voice coil bobbin; an outer convex part; a concave part comprising a surface, wherein a voice coil is adhered to the surface; and a boundary between the outer convex part and the concave part, wherein the voice coil is closer to the central convex part than the boundary; and a damper attached to said frame to support another end of said flat-type voice coil bobbin.