John Sayers’ Recording Studio Design ForumAn archive of johnlsayers.com, 2003–2022

Room within a Room

Started by yanni on 13 January 2006. 7 replies.

Originally posted at johnlsayers.com, topic 5447.

yanni
Hello all, it's been a while since I've been on this forum but I've just settled on the design for my sound proof rehearsal / recording room (no separate control room) which will be built in 6 x 4 metre room in our new house on a concrete slab. I want to build a room within a room, that is a self standing box about 100mm away from the existing walls and ceiling. The only thing that won't be isolated is the floor maybe, if I can do it within my budget I will. But if I can't I'll use thick carpet underlay under the carpet. I won't be pumping out huge bass frequencies anyway. Now my question is and because I've never really seen or experienced it in a real situation is whether an air gap all around the room of 100mm is really going to stop sound from travelling out ? I'm still sceptical. The inner room walls will be the normal stud construction with drywall/platerboard both sides and noise rated fibreglass insulation in between. The outer or existing room is a finished construction with the normal studs and drywall/plasterboard both sides. The entrance will be a glass sliding door on both the outer and inner rooms with all the sealing technology I can get my hands on. I know I've asked this question before and I've done the research but now it's crunch time - if anyone's had experience in this area please let me know. I need to be convinced. Thanks Yanni (from south of Melbourne Australia)
AndreasB
As far as I understand, you should remove the two inner drywalls ie. the ones facing eachother, leaving the studs and isolation bare and strap it up with vinyl straps or something that holds the isolation in place.. There's also some saying you should lift the inner wall and put some neoprene or acoustical rubber underneath the horisontal stud. But hey, if you're lucky Steven will answer this for you! best andreas
kendale
Aloha,
my question is and because I've never really seen or experienced it in a real situation is whether an air gap all around the room of 100mm is really going to stop sound from travelling out
There was a recent post about this here somewhere (I think the good master Sharward :wink: had some useful info)...in the meantime, I think a search is in order. A moment , please... :D Aloha 8)
enthalpystudios
In those examples above, the illustrations, take the last one for example.... separate studs, insulation, and double drywall (or even triple, should the mood strike), what is being assumed as far as where those studs connect (floor and ceiling)? Are they isolated from each other somehow? If one side were my outside wall (quiet room) and the other side were a 'loud room,' should the loud room side, and its floor, float to keep sound with in that room? I guess what I'm thinking about is taking an existing corner to make vocal booth. I'd add the two or 3 walls to the existing corner to make it look nice from the outside. Then inside, I'd float (on neoprene i suppose, if I can find any) an entire structure, the box, it's bottom, top, and sides....... well, I'd probably actually *build* in the reverse order.... but my point is.... if the inside framing is sitting on neoprene, with double or triple drywall inside, some 6-8 lb/ft.2 rockwool all around, out to the framing that encloses it within the larger outside room, double or triple drywall on that outer framing (outer framing connected to existing room/ceiling/floor..... How will I sit? Thats my plan... I can draw something I suppose, if that makes no sense. Just got to find some neoprene, I've got all my studs, drywall, and rockwool. Anyway.... didn't mean to hijack a thread, it just got me thinking is all... billy
knightfly
Yanni, the room-in-room you proposed is EXACTLY the same as the "40 dB" illustration in the STC chart Kendale posted - Now, follow that sketch to the right, step by step - note that you can REMOVE material and IMPROVE the wall at the same time. How's THAT for non-intuitive??!? But it's TRUE. If you compare the 40 dB wall with the 63 dB wall, you'll see that there's EXACTLY the same amount of material used but 23 dB difference in the result... So the advice you've gotten is right on the money - less is more, at least in this case. Here's a similar example that might give you the idea how to go about your space, and WHY (read the post on about the next-to-last page, starting with HALLELUJAH ... Steve P.S. - welcome back :D
yanni
Hi, Thanks everyone for all your advice - I appreciate the trouble people go to to reply to me on this forum - it takes time, research and effort and I think that is what is lacking in this world sometimes. I just feel guilty that I can't help others with their problems. Maybe when I start and or finish my sound proof room I can make available photos and experiences. My bands website is up and running with sound now so if anyone wants to hear (not high res however) what my music sounds like and maybe buy a CD (which was recorded in my previous house that had no soundproofing - we had to record acoustic stuff and vocals in between neighbours mowing and parties.) www.theswiftsmusic.com Thanks Yanni