An electro-acoustic transducer includes a diaphragm and an electro-magnetic motor that is coupled to the diaphragm. The motor includes a voice coil and a magnetic circuit that defines an air gap within which the voice coil is at least partially disposed. The magnetic circuit includes a first, axially polarized permanent magnet that provides a first magnetic flux path and a second, radially polarized permanent magnet that provides a second magnetic flux path. The first and second magnetic flux paths are arranged to interact with the voice coil to drive motion of the diaphragm.