Loudspeaker driver suspension

Abstract

A loudspeaker driver has a diaphragm connected to a surrounding frame by a roll suspension which extends around the diaphragm and within the frame. The roll suspension connects the outer edge of the diaphragm to the inner edge of the frame and flexes as the diaphragm is displaced to and fro axially relative to the frame. In order to provide for better integrity of the roll suspension during its displacement, and reduce unwanted deformation and concomitant distortion, the suspension roll is provided with pleats extending across the roll suspension transversely to the direction of axial movement of the diaphragm to create a series of undulations (peaks and troughs) around the perimeter of the roll suspension. In transverse cross-section, the roll suspension is parabolic. The roll suspension varies continuously between each peak and adjacent trough. Preferably, outer surfaces of each peak and adjacent trough merge to a common point on the outer edge of the roll, while their inner surfaces merge to a common point on the outer edge of the roll, such that the peaks and troughs effectively disappear.