Author: myfanwy4812
Subject: Make a Dead speaker
Cover half or more of the speakers with a wood board and about 4" of foam. Build a dead speaker by taking a throw away speaker, that is at least 30Watts and the same ohms as your regular cab, cutting all around the voice coil(without cutting the electric wires going to the voice coil itself) then damping it by placing a thick piece of foam on the face of the speaker... The voice-coil(center thing) will vibrate but the cone won't move because it is detached and deadened with foam... The vibrating voice coil will barely make a sound and it will use up 1/2 the Watts that your amp is putting out...(also just foam will against a speaker will work or a sound-absorbing enclosure etc.)
Also:
Amptone.com ultra gear-search page