Small tracking room inner room shape - URGENT HELP!!

HI - long-time lurker here - finally well into the project, and need some help! So. I've cruised this & other sites ad nauseum. Read Rod's book, as well as the Mitch Gallagher book on acoustic design. I have some good fundamenatal knowledge now. I have a new inner room to construct in my new tracking room, but I'm not sure what shape to build the room, within the space I have. The basics. I'm in Newcastle - Australia. I've been in the biz 20 yrs. I've been recording at this location for 7 years. I do lots of producing (singer-song-writers, bands etc). I record all manner of genres - and need to record virtually any instrument - lots of typical band stuff - but also lots of acoustic instruments, double bass, cello, bluegrass etc etc. Pretty much a bit of everything. So I can be loud - but - my main prob is NOISE GETTING IN, not noise getting OUT. So, passing traffic can be a prob as I;m very close to the road. Rain on the roof has been a prob in the past - but as you'll read, the new room has a more substancial roofing material than typical iron sheeting. The drawing is only of the new room which is under construction. It is an add-on to an existing garage, which has been my studio for 7 years. This existing room is approx 9 mtres long by 3 wide. I'm basically building this new room as my new main tracking room. So the old (existing) room will become purely control room, storage, and at some stage I will build a booth in there as a third space. So basically - the external shell is built as seen on the plan. I haven't spent a lot of time drawing it up - just basic dimensions. The walls are besser block (390mm by 190mm, by 190 high). They have been filled with solid concrete. The roof is (not drawn obviously) is a typical pitched, or gable style roof, constructed out of a sandwich-style roofing sheet called solarspan. http://www.solarspan.com.au/solarspan/r ... rview.html Its 90mm thick. The gable ends are constructed out of the same material. The product will help with thermal & sound isolation (rain noise etc). What I would love help on here, is the SHAPE of the inner room, yet to be built. I'm looking to construct a free-standing room within my new shell. I'm looking at a typical stud wall room, using treated pine. Then lined with gyprock - more than likely on the inside of the studs. I'll use rockwool between the studs. I'll then have to treat the inside room acoustically etc. The ceiling will not be flat - it will be a 'cathedral' style - pitched up high to about 3 metres in the centre, and approx 2300 at the walls. I don't have to worry about working out spans & timber sizes, engineering, as the builders are professionals etc - I just need to show them the shape & dimensions, and they will worry about the details & build it. But I need it QUICKLY!! One of main concerns also is the doors. Doors have given my hell over the years, always a weak spot. The current door is a stock standard solid core door 45mm thick. Obviously the new inner room will have another door opening inwards. But my experience to date has been fairly average, trying to get a good seal on double door systems. I'm wondering how to create a more substancial air-lock between inside, and the outside world. I'm also just not sure about getting the room right as far as reflections/nodes/antinodes etc. Kind of a bit of a goose when it comes to science & maths. Any help/feedback ASAP would be great!

Robbie - could you please post some pictures of the room so I can figure the ceiling. I'm aware of solarspan - it's a sandwich of steel sheet (colourbond) and polystyrene in between. I assume it spans with no rafters?

Hi! Thanks for getting back so quickly! Here's some pics. Yes, the other reason for solarspan was to eliminate the truss under the roof, giving me more room/air inside. Its not a large room, so I need to max out the height as much as poss. Please let me know if more pics/info are needed. We'll block up the front AFTER the inner room is built, as access will be much easier from the front whilst building. I was thinking of filling the front wall with sand, in case someone (if I sell) wants to turn it back into a garage one day. Obviously the window space you see inside the room will be cut through to the old section, and glass put in (1200 * 900), looking into the c/room.

Just wonder why, some people get stacks of response, while others get none..wierd.

Sorry Robbie - I started to model your building and got distracted and forgot about it . Here's where I'm at so far - you will need to build a room within a room like I've started in the model. Ive left some space between the two ceilings for Aircon ducts.