Help with basement studio design

I've got a basement room that is 21'x14'x10' (LxWxH) into which I want to put a control room. The goal is to isolate the sound from the rest of the house, and make a room that is acoustically pleasing, and potentially versatile enough to be a recording room or a control room. I've attached a drawing of what I'm working with. I've read about building a room within a room on a floating floor. I wondered if instead of just cutting small pads out of neoprene if it would be acceptable to use 4x6 horse stall mats which are also made out of rubber and cover the whole floor with that and then add the 2x4s and double plywood base. The stall mats are less expensive and seem to be about the right density, but I'm not sure. Also, how would you suggest the walls be done? Should I build a rectangle right inside of the main room, and then build the angled walls inside of that? Also, what about the ceiling? I was thinking of having it peak in the middle and slope down on the sides. Would that be the best? My budget is < $5000. The basement is your typical concrete floor and this room I want to use for the studio/control room area has 2 adjacent walls that are concrete, and two that are standard stud walls. Thanks again for any help you can give. -Eric

Hey mate, Maybe someone else on this forum can help you with the design, but I've heard that the horse stall mats are often used for acoustically decoupling studio areas. I can't guarantee the durability of them though, because most are made from recycled tyres, and I'm unsure of the potential long-term degradation. That having been said, it seems that it is a somewhat common practice for budget minded folks. I'll leave the design portion to those with more experience and better knowledge than me. :) Hope this helps! Murph'

Eric - I'd build around the ceiling beam like this. cheers john