US 12,356,168 B2
Loudspeaker cone with raised curved protrusions and methods for controlling resonant modes
Sean O′Brien, Harwood, MD (US); and Stuart W. Lumsden, Baltimiore, MD (US)
Assigned to Polk Audio, LLC, Vista, CA (US)
Filed by Polk Audio LLC, Carlsbad, CA (US)
Filed on Apr. 8, 2024, as Appl. No. 18/629,642.
Application 18/629,642 is a continuation of application No. 17/631,358, granted, now 11,974,111, previously published as PCT/US2020/044078, filed on Jul. 29, 2020.
Claims priority of provisional application 62/879,889, filed on Jul. 29, 2019.
Prior Publication US 2024/0381029 A1, Nov. 14, 2024
Int. Cl. H04R 7/12 (2006.01); H04R 7/26 (2006.01); H04R 31/00 (2006.01)
CPC H04R 7/125 (2013.01) [H04R 7/26 (2013.01); H04R 31/003 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A diaphragm having an inner opening, a central region proximate the inner opening, and an outer peripheral edge, the diaphragm comprising:
a front skin having a front surface; a back skin have a rear surface; a foam core encapsulated within the front skin and the back skin; and
a plurality of radially arrayed, distally projecting protrusions defined as convex surfaces or channel-like protrusions extending in spaced curvilinear arcs from the central region to a proximity of the outer peripheral edge;
wherein the substantially uniform cross-sectional thickness is 0.5 mm.