Abstract: Fixing of a voice coil (16) to a diaphragm (12) is performed by caulk-fixing a coil supporting member (26) to the diaphragm (12) and by fit-supporting the voice coil (16) by the coil supporting member (26). Hereby, the voice coil 16 is physically fixed to the diaphragm (12) and its fixing strength is heightened. The caulk-fixing is performed by subjecting a caulking projection of the coil supporting member (26) to a plastic deformation thereby to provide a caulk-fixed portion (26b), whereby deformation injurious to the acoustic property does not occur in the diaphragm (12). Further, the fit-supporting is performed by interposing a flange portion (16a1) formed at an upper end portion (16a) of the voice coil (16) between an engaging portion (26a) of the coil supporting member (26) and a central flat portion (12b) of the diaphragm (12) and holding it by them from upper and lower sides.

Abstract: A frame (14) supporting a diaphragm (12) by its outer periphery is constructed by a connecting ring (30) and a base (28) which comprises a bottomed cylinder portion (28A) and a mounting portion (28B) which extends radially outward from the bottomed cylinder portion (28A) which is a part of the magnetic circuit unit (18). The connection is achieved by the caulking of the ring (30) and the mounting portion (28B) with the diaphragm (12) clamped therebetween.

Abstract: A frame 14 supporting a diaphragm 12 by its outer periphery is constructed by a connecting ring 30—which is formed in an annulus following the shape of the outer periphery of diaphragm 12—to base 28 which comprises a bottomed cylinder portion 28A and a mounting portion 28B which extends radially outward from the bottomed cylinder portion 28A which is a part of the magnetic circuit unit 18. The connection is achieved by the caulking of the ring 30 and the mounting portion 28B with the diaphragm 12 clamped therebetween.

Abstract: Fixing of a voice coil 16 to a diaphragm 12 is performed by caulk-fixing a coil supporting member 26 to the diaphragm 12 and by fit-supporting the voice coil 16 by the coil supporting member 26. Hereby, the voice coil 16 is physically fixed to the diaphragm 12 and its fixing strength is heightened. The caulk-fixing is performed by subjecting a caulking projection of the coil supporting member 26 to a plastic deformation thereby to provide a caulk-fixed portion 26b, whereby deformation injurious to the acoustic property does not occur in the diaphragm 12. Further, the fit-supporting is performed by interposing a flange portion 16a1 formed at an upper end portion 16a of the voice coil 16 between an engaging engaging portion 26a of the coil supporting member 26 and a central flat portion 12b of the diaphragm 12 and holding it by them from upper and lower sides.