Patent ID: 6754362
Filing Date: 2004-06-22
Classification: H04R

Abstract:
A speaker, including a vibration system having a voice coil, a cylindrical voice coil bobbin carrying said voice coil and a vibrating member attached to said voice coil bobbin, and a magnetic circuit generating a magnetic force in cooperation with said voice coil to drive said vibrating member, and a throughhole in communication with a space enclosed by said voice coil bobbin for ventilating air in said space through a bottom portion of the magnetic circuit, for being used by facing a surface of the vibration system and a bottom portion of the magnetic circuit respectively to the inner surfaces of a casing so as to be held therebetween; the speaker further comprising a groove formed across an entire surface of said magnetic circuit in communication with said throughhole operable to ventilate air from said space to an area outside said magnetic circuit.