Planning and building a studio - scetchup file included!

Hello you acoustic semi-gods! I have just recently rented out a small ( 30 m2) office space near where I live in helsinki. I'm now in pursuit of a good design for a smallish control room and a vocal booth. I have been reading the forums and affiliated literature (Master handbook of acoustics 4th.ed.) as much as I have possibly been able but still I would very much prefer consulting you dear gentlemen before starting the construction with my novice skills. The office space is located in an apartment building on street level. The steet does not have too much action going on so my main concern is to try to isolate sound from reaching upstairs where my only neighbour lives. The volume levels that I'm having when working are normal CR volumes. Sometimes a bit loud but not reaching drum volume. My plans is that the small iso/vocal-booth would be able to handle recordings from a guitar amp so that I would not been kicked out of the building. The studio is going to be DAW based and will not be acommodating helluva lot of gear, so I 'm hoping that this moderately small space will do. My budget is (and hopefully stays) 6000-7000 euros. You can check the room dimesions from the attached scetchup file. My plan is to build the main roon within the recomended proportions of 1 : 1.14 : 1.39 resulting in height of 3m, width of 3.42m and lenght of 4.17m. There is a bathroom on the back ( not drawn, only the doorway) and a tiny kitchen in the wall next to it. The voc booths "roof" will be used as the main storage space, out of sight out of mind kinda way. Ventilation will be taken care of taking fresh air from the street side thru soundlock and taking the bad air out from the piping close to the ceiling. The timetable for the construction is that it hopefully would start in a week. I'll be working as the lil' helper of the contractor. Hopefully the frame and such would be finished in a 2 weeks of work. ------------------------- Enough of the la-la, I do have some questions that are keeping me wake at night so here goes: A1) I'm considering building a floating room inside the space. The problem is that it is more expensive and takes more space that a wall that would be build next to the old wall. Are the acoustical benefits very clear if I do leave the airspace between the walls. The bulding of a floating wall is somewhat difficult in this space. A2) If building a floating wall doeas anybody know a mechanic that one would still be able to mount the new wall to the old... somekind of a rubber slab or spring mechanic? Hope I make any sense to you? B) I'm only being able to fit one acoustic door to the street side wall (because lack of space). Any ideas how to maximise the isolating effect of the one door C) The door to the outside is located in a corner of the room. Building a basstrap to that corner is nearly impossible. Does it have an unwanted effect to the room acoustics if I build basstrapping in only 3 corners instead of four? Also I have been thinking of an idea how to make a movable basstraps to the back. ( Sketchup blueprint C ) Any ideas? D) I just recently heard Adam A7 monitors in action and was thinking of getting a pair to the forthcoming studio. Would people who have experience with those speakers think they would be an feasible option? The range to the monitors is going to be closer to 2.2meters. E) Also I would like to hear what kind of a ideas would you guys have in any other aspect of the design. Construction and/or taming the room modes ar anything. All help is and will be highly appreciated. Thank you very much indeed, A. Raski

And of course, here is the .skp file! There are couple of variants and ideas how the room might look... any feedback is highly welcome. The C option is the one I'm pursuing now. Cheers,

... Pretty please... :?:

Yes - I'd go with version C. Unfortunately you don't have enough depth to support a diffuser on your rear wall. I'd float a room as you suggested except I'd build it as an inside out wall with the drywall on the outside. see attached .skp file. That way you get internal treatment without loosing floor space. Your main advantage is the ceiling height - that's where I'd concentrate my bass traps. cheers john

:) :) :) Monsieur John, thank you very very dearly for your input !!!!!!!!!!!!!!!!!!!!!!!!! Your wall structure looks very interesting and I would have couple questions about it: Are the the wooden slots ment to act as a slot resonator, and do they need to be tuned specially for the room? By constructing the wall with only one layer of gypsum, do you lose the mass-air cavity-mass benefit? Or is it not significant enough to worry about? Your point on using the high ceiling as to my benefit on bass trapping has been taken in consideration on the new plan for the studio ( see .skp file) I have two possibilities for the ceiling: Sloping or even. I'm wondering is the sloping ceiling would be worth the construction trouble so that the ceiling basstrap would get a wider band of absorbion?? Also I was left wondering what is the reason why my room is too short to support diffusion. Doesn't diffusers work on all ranges? We are scheduled to start to lay down the structure on monday. All input is very welcome indeed! Thank you, APR

Heres a pic also,

APR wrote:

:) :) :) Are the the wooden slots ment to act as a slot resonator, and do they need to be tuned specially for the room?

Yes - you tune them to the low mid frquencies around 250 - 350 hz.

By constructing the wall with only one layer of gypsum, do you lose the mass-air cavity-mass benefit? Or is it not significant enough to worry about?

You retain the mass - air - mass, it's just a narrower airgap.

Your point on using the high ceiling as to my benefit on bass trapping has been taken in consideration on the new plan for the studio ( see .skp file) I have two possibilities for the ceiling: Sloping or even. I'm wondering is the sloping ceiling would be worth the construction trouble so that the ceiling basstrap would get a wider band of absorbion??

Yes - aim for the max absorption in the upper corners, i.e above the door to the studio and above the door into the control room.

Also I was left wondering what is the reason why my room is too short to support diffusion. Doesn't diffusers work on all ranges?

The aim of a mix room is to have a clean signal at the mix position. The sound from the speakers that passes you will reflect off the diffuser and come back at you. In your case it's only 2.4m (8ft) from the mix position to the rear wall so the sound will travel 4.8m (16ft) before you hear it again from behind 16msec later. The human ear can't determine the source until the two sounds are greater than 20msec of each other so in your case the two sounds are merged and create aural confusion. If you check out the control rooms with rear diffusers you will see that they are big rooms with more tha 10' (3m) from the console to the rear wall.

We are scheduled to start to lay down the structure on monday. All input is very welcome indeed!

good luck.:D Thank you, APR

Sincerely thank you for you help, Is there any good resource that you are aware of that has calculator for slot resonator panels in metric format ( just to avoid last minute calculation errors ,) Also, is it a recomended habit of making the slot resonator with varying opening is gap ( presumably to make it more wide ranged ) ? Thank you, APR

you can find an imperial/metric helmholtz calculator in the construction forum as a stickey. cheers john

:? Trouble ahead! I went to purchase the construction components from the 'handyshop' and this very professional carpenter guy got me confused with his theory how the studios walls should be built... huuuh... He insisted on design that would would be a lot easier to build but I'm really not that sure that it makes my moderately small studio space _sound_ good. His design would reguire additional absorbion to be built to the room. :?: Anyhow heres his design proposition... And yes, the Johns design look better because with it you do not need to build more absorbers on the surface of the wall. Well I'm a bit baffled and confused what to do. Johns wall looks more difficult to put up coz there is no room to get on the other side of the wall... Any help and or suggestions more than welcome! APR

:!: And here and the (wonderfull) perforated gypsum boards that I have been thinking of using... http://makeashorterlink.com/?A2F6130CD Cheers,