sound is always different in different scenarios, home, rehearsal, gig indoor or Outdoor. Don't waste too much time or money for absorber, just play. You can not controll all physic conditions??
I know what you're talking about
I don't have those problems onstage because I use IEM. It's our sound man who cares about it. But, if I'm paying for a room, I'd like it to have a nice sound, you know.
BTW, our sound man keeps telling us to use the IEM at the rehearsal room, but it's a problem, because the room is shared with other bands so the idea of miking the drum set every time is not viable.
I've tried to convince the band to get our own rehearsal room a few times. They don't see the need for it.