Various implementations include loudspeaker transducers. In some aspects, an electro-acoustic transducer includes: a diaphragm configured to move along an axis; a voice coil having a plurality of windings around the axis; a voice coil support configured to transfer forces from the voice coil to the diaphragm; a support structure that inhibits radial motion or tilting motion of the diaphragm and the voice coil support; and a magnetic core for driving the voice coil, the magnetic core including: two magnets having opposite polarity and approximately equal magnetic strength, where each of the magnets surrounds the voice coil, where a magnetic field from each magnet is approximately symmetric along the axis, and where the magnetic field from both magnets drives the voice coil.