An annular surround for a loudspeaker cone wherein a radial cross-section of
the
surround varies around the circumferential extent of the surround, so as to accommodate
peripheral expansion or contraction of the surround by bending. Thus a trough shaped
cross-section of the surround may vary sinusoidally with angle around the polar
axis of the surround between a semicircular and semielliptical cross-section. The
trough section may bland to an adjacent portion of the surround by a fillet which
also varies sinusoidally in cross-section in phase with the variation of the trough.
