Patent ID: 7551749

Claim:
An electro-acoustic transducer comprising: a) a magnet assembly providing a first magnetic flux gap and a second magnetic flux gap; b) a first voice coil positioned in the first magnetic flux gap; c) a first diaphragm that is mechanically coupled to the first voice coil and to a frame, the first voice coil constructed to move the first diaphragm in a first direction in response to receiving a first input signal; d) a second voice coil positioned in the second magnetic flux gap; and e) a second diaphragm that is mechanically coupled to the second voice coil and to the frame, the second voice coil constructed to move the second diaphragm in a second direction in response to receiving a second input signal, the movement of the second diaphragm reducing a vibration imparted to the frame by the movement of the first diaphragm when the first direction is substantially opposite to the second direction, the first and second diaphragms being located on a common side of the magnet assembly, wherein the first input signal applied to the first voice coil generates a first magnetic field and the second input signal applied to the second voice coil generates a second magnetic field, the first and second voice coils being wound such that the second magnetic field has opposite polarity to the first magnetic field at a point where the first and second magnetic fields cause modulation of magnetic flux in at least one of the first and the second magnetic flux gaps when the input signals are such that the first and second directions are substantially opposite.