Patent ID: 6611604
Filing Date: 2003-08-26
Classification: H04R

Abstract:
An ultra low frequency transducer comprising:a basket having a square front opening; a driver assembly supported by the basket comprising a permanent magnet and a reciprocally supported voice coil, the voice coil connectable to a signal source, whereby the driver assembly is adapted to convert signals from the signal source into long reciprocating axial motion of the voice coil; a diaphragm with a square periphery and a center portion, the center portion being linked for movement with the voice coil to produce long excursions of the diaphragm; and a square flexible surround between the periphery of the diaphragm and the front opening of the basket, the surround comprising four straight side sections of equal length with four curved corner sections between adjacent side sections, the surround being curved in normal cross section defining an arc, the surround having at least one pleat in each corner section, the pleat longitudinally defining an arc concentric to the arc of the surround, and wherein the straight side sections of the surround are substantially free of pleats.