Here's something you don't see every day, drums and loudspeaker driver enclosures. The SubDrum is said to be an all-in-one sound system. You use a coax driver (tweeter and midrange) within the drum tom toms, and a woofer within the bass drum. A just like that, you have a satellite and subwoofer system of sorts. As a compact and complete all-in-one sound system, the SubDrum system attached speaker drives to drum heads, and then tightens the head a lot to keep it taunt. The float-in-head driver suspension 'technology' claims to "virtually eliminate cabinet resonance distortion".