Abstract: The diaphragm has an outer flange and an inner portion which is deflectable relative thereto, with the inner portion having a lone, primary annular corrugation connecting a center of the inner portion to the outer flange and which, when viewed in cross section, has the general shape of one full cosine wave. A plurality of radially disposed waves present ridges to the high pressure side of the diaphragm, with each fairing in amplitude from a maximum generally midway of the diaphragm radius to zero generally at the center and at the outer flange. Each of the radial waves is arithmetically added to the primary wave so as to be integral therewith and has the general shape of one full cosine wave when viewed in cross-section both along and normal to the length of the ridge. In one embodiment, similarly shaped annular corrugations are added onto the primary corrugation as secondary annular waveforms so as to provide the diaphragm with greater sensitivity and longer deflection (stroke) capabilities.