My brothers band is changing location and they're now getting a pretty big room in a basement. The problem here is that every wall is massive wall bricks and cement so it's totally impossible to play there like it is now.
Any cheap suggestions on what to do with the walls and ceiling? We're trying with some soft blankents on the walls now, but it doesn't really make the effect we want.
Avoid sound traveling directly at walls... try aiming amps at slightly skewed angles. Having the sound reflecting at one wall and bouncing staight back to the wall behind it can be a big source of reflective sound, especially at the volumes often used in rehearsal rooms. The more reflective sound, the louder folks turn up so they can be heard, which adds to the problem.
If you can swing it financially, plexiglass barriers around the drum set allows everyone else to lower their volume and still be heard, while still maintaining good eye contact. This can help as well. A cheaper alternative to plexiglass might be a carpeted wooden wall (3' high?), we used to use those at Berklee in the late 70's for isolation in studio recording.