Patent ID: 7577269
Filing Date: 2009-08-18
Classification: H04R

Abstract:
1. An electro-magnetic transducer, comprising: (a) a housing, the housing including a magnetic structure with at least a pair of magnetic poles of opposite polarity, the pair of magnetic poles creating a first area of magnetic flux concentration; (b) a vibratable sound-producing member at least partially formed of magnetically permeable material, the sound-producing member having a first end rigidly affixed within the housing and a second vibratable end disposed in the first area of magnetic flux concentration; (d) a coil positioned to induce a second magnetic field in the sound-producing member, the second end of the sound-producing member being vibratable toward and away from the magnetic poles to produce acoustic waves in the area of magnetic flux in response to electrical current passing through the coil; and (e) an acoustic conduit for receiving sound waves generated by the sound-producing member and directing such waves from the area of magnetic flux concentration through at least one of the magnetic poles to a location outside the housing.