Hi there Gernot, and Welcome!
First of all, please read the
forum rules for posting (click here). You seem to be missing a couple of things!
The space we have available is on the first floor ...
Just to make sure we are on the same page, for some countries "first floor" means the one at ground level, with nothing underneath it except dirt, but other countries call that the "ground floor", and for them the "first floor" means the one above the ground floor. Which is it in your case? I'm VERY much hoping that it means "the floor at ground level, with nothing under it."...
The slab to slab ceiling height is 2,85m, so this is our main restriction.
Is that the clear height across the entire space that you have? Or are there also intervening beams, HVAC ducts, water pipes, gas pipes, electrical trays, and/or other things that reduce the height?
Photos of the entire space, showing those details, would be very useful...
There is a Gym on the floor above us (not the weights section...
OK, but what part is up there? The part where they do high impact aerobics? Dance? Treadmills? Anything else that involves impact noise in the bilding structure?
My design for the layout:
Very nice visually, but... (and please don't get upset by the comment...) very lousy acoustically. First and foremost: get rid of those curved walls! Those are a huge mistake. Curved walls focus sound like a lens focuses light, and does so in different patterns for different frequencies. A couple of years back I got called in to fix the acoustics of a church that had built their main sanctuary with a curved wall at the back of the stage... Major issues trying to treat that. Your curved walls MUST go. (Even worse, the mix position seems ot be at or very close to the focal point for rays, for that wall...
)
Next, you seem to be aiming for an RFZ based design for your control room, but the angles are way off: you do indeed have some pretty major first-order reflections arriving at the mix position, and with no way to treat them because of where they are coming from. The angles need to be fixed, by ray-tracing.
You also seem to be aiming to soffit-mount your mains ("flush mount"), which is excellent, but you are not showing the complete enclosure of the soffits (the "other" walls of the soffits, not the wall that has the infinite baffle on it). In the same region, you are also missing the final part of the outer leaf that encloses all of isolated rooms...
Then there's the issues of practicality: right now, there is no direct path into the live room! All load-in and load-out must go through the control room with the current plan, meaning that the musicians will be dragging their instruments, gear, and belongings across the knees of the producer, sitting on the client couch, in order to set up, then drag it all out again after the session is over. In addition, anyone in the LR who needs to go to the bathroom, answer the phone, get a cup of coffee, or leave for any other reasons, must also interrupt the session in the control room to do so, interposing themselves between the producer/client and the engineer... Not a good layout at all.
There's also the issue of sight-lines: Only about a quarter of the live room is visible from the mix position, and there is practically no visibility at all between the live room and vocal booth, so it's hard to see how a recording session for " live-tracking an entire band across multiple rooms" would work out! Musicians need to be able to see each other, as well as hear each other, to keep it tight and smooth. Yet, there's a great view from the storage room into the Live Room...
Then there's the curious office/storage room that is isolated on the other side of the LR, behind a pair or rather expensive acoustic-rated sliding glass doors... that seems to be a waste of expensive space, and expensive doors. Offices and storage rooms don't normally need to be acoustically isolated!
On the other hand, in the places where acoustic rated sliding glass doors really would be justifiable, there aren't any! Between the vocal booth and the two control rooms.
And finally, the rear end of Control Room B is almost as terrible as the rear end of Control Room A: Control rooms should never get narrower towards the rear.
So overall, I'd say that the layout needs some SERIOUS re-thinking! It looks to me like it was done by an architect with a flair and talent for great aesthetics, but not so much idea at all of how professional studios actually work in real-life, even less the acoustic standards that need to be followed. You should probably get an experienced studio designer to re-do the entire thing, starting with a blank slate. I'm sure there's much better ways of laying out a facility like that, especially seeing that budget does not seem to be a problem here. With the type of money you are talking about for this type of layout, you could get something far more functional, better isolated, and with much better acoustics.
Feel free to comment and tear this all apart!
No problem! Mission Accomplished....
I'm about to start on acoustic calculations and all the finer details
I seriously would not bother with that: There really isn't much that could be done to salvage the acoustics of the main control room, no matter how it is treated. With that shape, it is pretty much doomed to failure. So don't waste your time trying to figure that out. Or rather, don't waste your money hiring a FEM/FEA engineer with the acoustic knowledge and the necessary understanding of how to set boundary conditions for such an analysis, since the conclusion is pretty much foregone. Yes, you would get good graphs that predict the behavior of the room reasonably accurately, but to be very honest, there's no need for that since the outcome is obvious: curved rear wall? Outcome = acoustic disaster.
2,85m minus floating floor,
Why do you want to float your floor? Are you aware of the huge cost and major complexity of doing that correctly? You probably should read the thread below, to understand the issues.
http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173
If you really do need to float it then, you had better add a very large extra item to the budget. That will not be cheap to do.
suspended ceiling,
Why do you want a suspended ceiling? There is no need for that. If your inner-leaf ceiling is designed correctly, and suitably spaced away from the existing outer-leaf ceiling, then that's all you need. Adding an additional suspended ceiling would cause acoustic damage, not acoustic benefit. Firstly, it would create a 3-leaf system, thus reducing your low frequency isolation, and secondly it would reduce the overall room volume and ceiling height, when you are already rather limited there.
ventilation ducts etc.
You don't have enough height to put your HVAC in the ceiling. Put it in the wall cavities. You have enough floor space to do that, and you have wasted space around the structural columns anyway, which could be put to good use for HVAC ductung, silencers, etc. The AHU could probably go in the storage room, or in the ceiling area above the lounge. But it would be a mistake to try to fit in HVAC above the rooms when you already have such limited space up there.
I'm hoping to get at least 2,5m of usable height in the finished room.
Not if you float your floor you wont! That's for sure. 10 to 15cm of concrete, plus another 10 to 20 for the cavity and mounts (at least), plus another couple for finish flooring... there goes probably 40 cm already. Then you'll need at least 15 to 20 for the inner-leaf ceiling, even if you do it inside-out. That's at least 60 cm out of 285, leaving 225 max, and that's with a lot of luck and very careful design. And no HVAC, of course. If you wanted to put HVAC up there too, then you'd loose another huge chunk.
(excluding spot ceiling absorbers)
Treatment on the ceiling does not count for acoustic calculations: the room ceiling is the solid, hard, rigid, massive surface of the inner-leaf. Anything that hangs below that only has visual impact, not isolation impact. Your ceiling height is the distance from the top surface of the final finish flooring (which is on top of the floating slab, which is on top of the isolators, which is on top of the existing slab) up to the bottom surface of the inner-leaf ceiling (which is hung from the inner-leaf framing, which is separated from the existing outer-leaf ceiling by whatever distance is needed to obtain the amount of isolation you need at the frequencies where you need it). That's what I'm referring to with the 225 cm figure. That's the actual acoustic height that you'll have. Treatment will lower that further visually. And that doesn't even consider the joists, assuming you build inside-out to save space. Of course, if you build conventionally, then the ceiling would be even lower. If you get it designed really, really carefully, with very high density (and very expensive) isolation materials, then you might be able to get that up to about 240 cm, but I'm not so confident about that, without doing the calculations...
Any input on this particular issue is more than welcome!
First suggestion: don't float your floors, for all of the reasons given in that link! Then, use inside-out ceiling construction to save space, and keep all (or most) of the HVAC in the wall cavities, not the ceiling cavity. Worst case, if you do need impact isolation for some of your gear (eg: drum kit, bass cabs, etc.) then just put them on isolated "drum riser" type platforms, so you don't need to float the entire floor. Unless, of course, you really do need high levels of isolation, in which case you don't have much choice, and will have to float.
I hope all of the above doesn't dishearten you too much, but you DID ask for honest commentary! So that's what you got.
The good news is that you have a decent sized space with good possibilities. The bad news is that the current layout is .... umm ... welllll .... shall we say "rather deficient"!
- Stuart -
) and a clothing store beneath. Sound-proofing will be crucial in any case.
Any advise is greatly appreciated.