I'm having a problem in a live staging setup, in which I have 3 guitar amps and 2 bass amps, all miked, feeding back on on-stage rifle mics. Just to specify, there isn't any way to line out from these amps, for reasons unimportant to this question. What I want to know really is what acoustic shielding techniques are used for containing the sound to their own microphones?
EDIT: Another thing I want to bear in mind is the heat of the amps, because they're positioned under the staging which is always covered by the lighting system, thus meaning they will get hot. I really don't want anything melting with the heat, especially coming from the valves in the amp.
EDIT: In terms of the staging, it's for a production in a theatre with a live band. There is staging that rises up to two balconies which the band play under. The amps are situated with the band, and the microphones in question are 2 hanging from the rigging in the ceiling, and 2 at the front of the stage. I think a large part of the bleed is coming from the closest rifle hanging from the ceiling which is probably around 7-8m away from the amps. Also, there are fallback monitors at the front of the stage and a set in with the band.