Transducer and method of operation

A speaker, including a voice coil, the voice coil comprising:

• a circular magnetic channel having a longitudinal axis, including:
• an exterior magnetic cylinder positioned concentrically to the longitudinal axis and having a first plurality of magnetic poles at an interior face which are generally transverse to and pointing at the longitudinal axis and having a first plurality of magnetic flux forces such that each magnetic flux force travels between a first pole on an inward face of the exterior magnetic cylinder, around an open end of the magnetic cylinder, and back to a second pole of an exterior face of the exterior magnet cylinder;
• an interior magnetic cylinder positioned concentrically to the longitudinal axis and having a second plurality of magnetic poles at an exterior face which are generally transverse to and pointing away from the longitudinal axis and having a second plurality of magnetic flux forces such that each magnetic fluxforce travels between a first pole on an exterior face of the interior magnetic cylinder, around an open end of the interior magnetic cylinder, and back to a second pole of an inward face of the interior magnet cylinder;
• a base magnetic ring positioned at one longitudinal end of the exterior and interior magnetic cylinders to form the circular magnetic channel and having a third polarity of magnetic poles at an inward facing face which are generally parallel to the longitudinal axis and having a third plurality of magnetic flux forces such that each magnetic flux force travels between a first magnetic pole of an inward face, around the open end of the circular magnetic channel, and back to
• a second pole of an exterior face of the base magnetic ring,
• wherein the first plurality, second plurality, and third plurality of magnetic poles are the same polarity,
• a moveable coil assembly at least partially positionable within the circular magnetic channel wherein the coil assembly may move in a direction generally parallel to the longitudinal axis when current is applied to the moveable coil assembly.

A method of moving an air cone of a speaker, the method comprising:

• forming a first plurality of magnetic poles having a first plurality of magnetic flux lines at an interior face of an exterior magnetic cylinder positioned concentrically about a longitudinal axis such that the magnetic poles at the interior face are generally transverse to and pointing at the longitudinal axis;
• forming a second plurality of magnetic poles having a second plurality of magnetic flux lines at an exterior face of an interior magnetic cylinder positioned concentrically about the longitudinal axis such that the second plurality of magnetic poles at the exterior face are generally transverse to and face away from the longitudinal axis;
• forming a third plurality of magnetic poles having a third plurality of magnetic flux lines at an inward channel face of a base magnetic ring positioned at one longitudinal end of the exterior and interior magnetic cylinders to form a circular magnetic channel wherein the third plurality of magnetic poles are generally parallel to the longitudinal axis at the inward channel face,
• wherein the first plurality, second plurality, and third plurality of magnetic poles are the same polarity,
• applying a current to a moveable coil assembly at least partially position within the circular magnetic channel,
• moving the coil assembly in a desired direction in response to the applied current and polarity, and
• coupling the air cone to the coil assembly such that when the coil assembly moves, the air cone moves to generate an air waive.