PURPOSE: To expand reproducible frequency band and make possible reproduction of high fidelity by so forming a magnetic circuit which supplies magnetic fluxes to each voice coil as to become magnetically integral.

CONSTITUTION: A diaphragm 1 has a plurality, e.g., 3 pieces, of cone form vibrating parts 1a which are integrally fromed by way of connecting parts 1b. Voice coils 2 are provided in correspondence to the respective vibrating parts 1a of a diaphragm 1 and one end thereof is bonded to the central position of the vibrating parts 1a. The respective voice coils 2 are supported by dampers 3 and the circumferential edge part thereof is supported to a frame together with the circumferential edge part 1c of the diaphragm 1. A magnetic circuit 4 which supplies magnetic fluxes to the voilce coils 2 consists of a yoke 5, a magnetic pole plate 6, magnetic center poles 7 and magnets 8. This magnetic circuit 4 is so formed that the circuits supplying magnetic fluxes to the respective voice coils 2 become magnetically integral. Thereby, the expansion of reproducible frequency band and reproduction of high fidelity may be performed.