Because I've been playing with a couple of LOUD bands lately, one Funk band, the other Rock, I needed to create an isolation box for my microphones. As we were playing, I would get more of the other instruments through my mics than the didge itself. Not necessarily a good situation.
I used an old plywood box. It was actually a kid's pretend microwave oven that I saved from the landfill by doing a little "dumpster diving" and I tweaked it for this purpose.
I cut two 2" holes in the back for my microphones (I use two mics so that I can do some stereo effects) and lined those holes with foam to hold the mics. I lined the entire inside of the box with foam for sound insulation, and cut an opening in the front for the didge to slide into. The mic placement is such that they are aimed properly at the foot of the didge.
We had 2 gigs this weekend and a SLEW of practices last week where I used it, and it made a BIG difference. The one adjustment I need to make is to use some form of acoustic foam instead of upholstery foam. Seems the upholstery foam still reflects some of the sound that leaks in, and I need to cancel it out. I might just try some of that "fingered" mattress pad foam and see how that works before I splurge on any of the studio foam that's available.
-jm