I'll take a closer look at the layout of the rooms themselves later on- short on time right now.
About the HVAC- my advice would be find an HVAC guy who has worked on sound-control systems before. The guys on the board here can give advice on some of the finer details, but in the end having a guy who knows what he's doing out there putting it together is your best bet. Like you mentioned before, the HVAC can make all your other sound-control measures worthless if it's done wrong or sloppy. And this is a pretty big HVAC system we're talking about, by the sound of it. Don't cut this corner on us! You have the potential for an awesome space!
Another thing about the HVAC- if it's that close to studio B, you might want to sheathe both sides of the walls nearby, just to put a 2-leaf wall system between the studio and the HVAC unit.
About the floor- If you're spacing the neoprene pads at 24", then your floor only has a 36" span. If you were using 1x4 under the plywood, then MAYBE it'd deflect a little bit, but a 2x4 laid flat will go 24" without problems. The plywood deck all on it's own can span that. If you're worried about it, build yourself a little platform, 24"x24", just like the floor you'll be floating. Put a neoprene pad in each corner, and then jump up on it. If it deflects too much, then turn the 2x4s on their sides and build it that way. IMHO there's no reason you'd need to use 2x6s on end for a floating floor that's got neoprene pads supporting it at 24" centers.
For 36" centers, 2x4s on their ends may serve you better. Again, you can build a little test platform and try it out.
If you're looking to cut costs in the floor system, and the 2x4s laid flat will work for you, then you should be able to build the floor out of 2x2 framing. It's the depth of the framing member that determines it's strength, and a 2x2 is just as deep as a 2x4 laid flat. Again, test it if you're not sure. Building test platforms for your floors might seem nitpicky, but knowing beforehand how your floor will feel will make you much more confident while you're building. Better to learn what will work for you before you get it all in place- especially if you'll be building your walls up off this floating floor...
Hrm, just thinking as I type this up... if you go with the 2x2 floor, you should probably use 2x4s laid flat around the perimeter of each floating floor. The reason I say this is because that's where the stud walls above will be built up. And while you could easily nail the studwalls down to the 2x2s, the neoprene pads under those walls will be carrying the load of the walls AND the ceiling you'll be building off them. Making the neoprene pads under these walls wider will help them carry the load.
Hope I'm making sense... it makes sense to me... *shrug*
Im not sure you'll have to insulate between the framing members, either, whether they're 2x6s on end or 2x4s laid flat. If this is over concrete slab, and there's just earth under that, then is it a big deal to have an open space below the floor? I could be very wrong here, but who cares if those cavities resonate?
That ceiling height is awesome. Especially since there's effectively another few feet above it. This means that guys could conceivably get up there, above the ceiling of your recording rooms, and move around and work up there, even with a 10' or 11' ceiling.
Kase
www.minemusic.net
well done. The problem I see is that you have squeezed all the studios into one area creating isolation problems. What if you swapped the studioB with the offices with the record label (preferably the studio managers office) in between to separate them. I would definitely consider a 5:1 surround control room and for a facility of this size I'd look at a larger tracking room as you have the space, that's a pretty big lounge area.
