Muffling
Drummers muffle their drums using special drumheads like double-ply heads, "control ring" heads, and "hydraulic" heads, or various materials placed on the drumhead like o-rings, duct tape, muffling clamps, and a product called Moongel, which is a blue, sticky, gel-like substance also used to dampen cymbals. Drummers also place foam, pillows, or blankets inside the bass drum to reduce resonance and overtones.
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