Re: Cutting a hole in the bass drum...How big, methods etc...
I use a standard sized 22 x 16 bass but it sounds a lot bigger using a particular method:
I used an Evans EMAD batter head with the largest foam insert. I use circle of a(n old) coated Ambassador head Gorilla Glue'd to the spot where the beater makes contact. My resonant head is a Powerstroke 3 with a 4" hole cut in the CENTER with nothing inside the bass drum whatsoever. The reason for a center hole, is because the center has the least tone of the drumhead, therefore, cutting a hole there, gives a modicum of tone reduction compared to cutting one on the perimeter region. Plus, in certain situations where you want more "tone" and less "kick", you place the mic near the edge, instead of inside the hole. This setup provides an extremely versatile miking capability for various styles of music and rooms.
Another advantage to the center hole, is that the drum evacuates the air a bit faster than if the hole were offset, being that the impact of the beater is approximately directly across the drum. This allows more punchy reaction of the heads, but can be balanced by a higher tuning of the drum. You can get a HUGE sound this way, especially since there is nothing inside the drum inhibiting the maximum air volume inside and quick evacuation.