[quote name='OutToPlayJazz' post='461796' date='Apr 14 2009, 09:28 AM']Big hollow stages don't help, either - Too much boom. Wherever possible, make sure your cab/combo is making good contact with the floor, ie. not on an amp stand or on wheels.[/quote]
If you allow your cab to acoustically couple with a hollow stage, the stage can act like a resonance chamber which is what causes the extra boominess. By isolating the cab from the hollow stage, you can control the lows a lot better with the benefit that your sound can have more focus.
Also, if your cab is rear ported then by putting it up against a wall, it also helps reduce boom.