CPC Subgroup
H04R 7/26 Damping by means acting directly on free portion of diaphragm or cone (air damping H04R1/28)
Full Title
Diaphragms for electromechanical transducers (in general F16J3/00); Cones (for musical instruments G10 ) > Damping by means acting directly on free portion of diaphragm or cone (air damping H04R1/28)