Patent ID: 6738490
Filing Date: 2004-05-18
Classification: H04R

Abstract:
A magnetically dampened loudspeaker for generating sound from an electrical current, the loudspeaker comprising:a voice coil through which the current flows; a diaphragm attached to said voice coil; a pole assembly defining an annular gap in which the voice coil is located, the annular gap having an inner and outer diameter; a permanent magnet for producing a magnetic field in the annular gap, the magnetic field interacting with the current to produce an axial movement of said voice coil; at least two magnets for dampening and thus limiting the movement of said voice coil; wherein said pole assembly includes a backplate for supporting a pole yoke, said pole yoke defining the inner diameter of the annular gap and extending through said permanent magnet, and a top plate, said top plate defining the outer diameter of the annular gap; and wherein said at least two magnets include a first dampening magnet supported by said pole yolk and a second dampening magnet supported by said voice coil.