I think you mean "strong electromagnets carrying an alternating current", like the ones in mains transformers and motors. read more
Contrary to expectation, the poles of the magnets are oriented along one of the minor axes of the ellipsoid, not the major axis. Neodymium magnets in 'ordinary' shapes produce boring 'plinks' when they snap together. Something about the shape of these magnets makes the sound much longer-lasting and entertaining. read more
Effect of Other Magnets Nearby. Recall science class when iron filings are dropped onto a piece of white paper over a magnet. The filings trace lines of magnetic force. If another magnet is pushed nearby, it changes the lines of force. Hence, a powerful magnet near your speaker is going to distort the lines of force and distort the sound. read more