A diaphragm (34, 34B; 100, 100B; 200, 200B) comprising: a disc (38, 38B; 104, 104B; 204, 204B) formed from a first material; and a rim (36, 36B; 102, 102B; 202, 202B) formed from a second material; wherein the rim (36, 36B; 102, 102B; 202, 202B) comprises: a wall (106, 106B; 206, 206B) having a first end (108, 108B; 208, 208B) and a second end (110, 110B; 210, 210B); a lip (112, 112B; 212, 212B) extending substantially perpendicularly from the first end (108, 108B; 208, 208B) of the wall (106, 106B; 206, 206B); a bridge (114, 114B; 214, 214B) extending substantially perpendicularly from the second end (110, 110B; 210, 210B) of the wall (106, 106B; 206, 206B); and a fork (118, 118B; 218, 218B) extending from the bridge, the disc (38, 38B; 104, 104B; 204, 204B) and the rim (36, 36B; 102, 102B; 202, 202B) are a unitary piece, characterized in that the rim (36, 36B; 102, 102B; 202, 202B) has a Shore A durometer hardness of between about 40 and 110, the disc (38, 38B; 104, 104B; 204, 204B) further comprises a plurality of apertures positioned around a periphery of the disc (38, 38B; 104, 104B; 204, 204B), and the rim (36, 36B; 102, 102B; 202, 202B) further comprises a plurality of bonds which fill the apertures, wherein the bonds each connect a first flange of the fork (118, 118B; 218, 218B) with a second flange of the fork (118, 118B; 218, 218B). a disc (38, 38B; 104, 104B; 204, 204B) formed from a first material; and a rim (36, 36B; 102, 102B; 202, 202B) formed from a second material; wherein the rim (36, 36B; 102, 102B; 202, 202B) comprises: a wall (106, 106B; 206, 206B) having a first end (108, 108B; 208, 208B) and a second end (110, 110B; 210, 210B); a lip (112, 112B; 212, 212B) extending substantially perpendicularly from the first end (108, 108B; 208, 208B) of the wall (106, 106B; 206, 206B); a bridge (114, 114B; 214, 214B) extending substantially perpendicularly from the second end (110, 110B; 210, 210B) of the wall (106, 106B; 206, 206B); and a fork (118, 118B; 218, 218B) extending from the bridge, the disc (38, 38B; 104, 104B; 204, 204B) and the rim (36, 36B; 102, 102B; 202, 202B) are a unitary piece, characterized in that the rim (36, 36B; 102, 102B; 202, 202B) has a Shore A durometer hardness of between about 40 and 110, the disc (38, 38B; 104, 104B; 204, 204B) further comprises a plurality of apertures positioned around a periphery of the disc (38, 38B; 104, 104B; 204, 204B), and the rim (36, 36B; 102, 102B; 202, 202B) further comprises a plurality of bonds which fill the apertures, wherein the bonds each connect a first flange of the fork (118, 118B; 218, 218B) with a second flange of the fork (118, 118B; 218, 218B). a wall (106, 106B; 206, 206B) having a first end (108, 108B; 208, 208B) and a second end (110, 110B; 210, 210B); a lip (112, 112B; 212, 212B) extending substantially perpendicularly from the first end (108, 108B; 208, 208B) of the wall (106, 106B; 206, 206B); a bridge (114, 114B; 214, 214B) extending substantially perpendicularly from the second end (110, 110B; 210, 210B) of the wall (106, 106B; 206, 206B); and a fork (118, 118B; 218, 218B) extending from the bridge, the disc (38, 38B; 104, 104B; 204, 204B) and the rim (36, 36B; 102, 102B; 202, 202B) are a unitary piece, characterized in that the rim (36, 36B; 102, 102B; 202, 202B) has a Shore A durometer hardness of between about 40 and 110, the disc (38, 38B; 104, 104B; 204, 204B) further comprises a plurality of apertures positioned around a periphery of the disc (38, 38B; 104, 104B; 204, 204B), and the rim (36, 36B; 102, 102B; 202, 202B) further comprises a plurality of bonds which fill the apertures, wherein the bonds each connect a first flange of the fork (118, 118B; 218, 218B) with a second flange of the fork (118, 118B; 218, 218B). <EOS>