Patent ID: 7065225
Filing Date: 2006-06-20
Classification: H04R

Abstract:
1. An electromagnetic transducer comprising: a cup including a back plate portion and a substantially cylindrical wall portion; a first magnet magnetically coupled to the back plate portion of cup; a first drive plate magnetically coupled to the first magnet opposite the back plate portion of the cup, the first drive plate defining a first drive magnetic air gap with the wall portion of the cup; a second magnet magnetically coupled to the first drive plate opposite the first magnet, and having a magnetic polarity substantially opposite a magnetic polarity of the first magnet; a return path plate magnetically coupled to the second magnet opposite the first drive plate, and defining a low reluctance return path gap with the wall portion of the cup; wherein magnetic flux flows over the return path gap in an orientation substantially opposite that of flux flowing over the first drive magnetic air gap.