Construction Started...

Yippy... :D Some of this may look a little strange, but I'm having to work around a few things, plus doing everything by yourself makes it a little slow. These aren't great but I know how we all love pictures; here's the start to where I am now. Hope you enjoy. Arthur In the beginning was a basement... full of junk :lol:

Vocal booth starts, air boxes and misc.

Sheetrock starts...

Nice Pics. Keep them coming! Andre

Are there studs behind the "R-Tech" stuff along the concrete wall? I'll be starting my basement studio soon and will be putting up some R-19 insulation up in the ceiling (1st floor) this weekend and also want to plan on putting something up for the walls before the "real walls" go up...

"Are there studs behind the "R-Tech" stuff along the concrete wall?" No, it's just glued to the concrete walls, I didn't have a moisture problem and that whole wall is under ground. So all I really wanted was a little barrier between the blocks and my interior walls, hope that makes sense. Arthur

Arthur, cool pix, thanks - can you explain what R-Tech is? couldn't quite make out the company name from the pix - either a description, or a link would be great... Steve

Thanks Steve, the R-Tech is basically just 3/4" rigid plastic insulation, it's what was recommended to put on the blocks as a "just in case" moisture barrier, insect resistant, yadda yadda. http://www.premier-industries.com/insulfoam.cfm?topic=eps One nice effect that I didn't expect was it seemed to be very non-reflective, the room just seemed tighter if that makes sence. I also found a good deal, at least I thought it was, on Roxul RHT 40, 3" was .38 sq/ft and 2" was .26 plus free delivery. The guys name is Larry Herron [removed], he's in Chattanoga TN, maybe this can help someone else out. I hope to have more pics next week, thanks again for all the input. Arthur

OK, that's kind of what I thought - are you putting any porous insulation behind your wall panels, or what? I'm asking because all the foam insulation I've seen is closed cell, and doesn't absorb much - it also doesn't damp the wall panels to keep them from ringing. In fact, I generally don't recommend this stuff for anything inside a studio for that reason; although I see why you put it where you did - So, what's the rest of your wall construction going to be like?

Steve, I was planning on just butting my studs up against the foam, then 3" of Roxul and cloth cover for absorbtion on the rear half side walls, with slat resonators at 6 degrees and bass traps in the front half where my console sets. Absorbtion and bass traps on the back wall and ceiling. If that doesn't sound right let me know, are you thinking I may need sheetrock or something against the foam? I guess I should have posted my floor plan, I did but it is in a differant section plus I've kinda refined it some. I'll try to up date and post so you can see exactly what I'm doing. Thanks for the input and double checking me, i'm trying not to miss anything so any help is greatly appreciated. Arthur

Arthur, I was afraid that whas what you were doing - if your isolation isn't a problem (meaning the concrete is doing a good enough job) then you can certainly do that - but the minute you put wallboard on those frames you've just "given away" several dB of isolation by having the studs in contact with BOTH leaves of your sound barrier. IF you're not doing that anywhere, no biggie - if your outer concrete is isolation enough, it doesn't matter what you do inside other than adding a second leaf to the wall... Steve

Steve, those two walls are underground so the sound getting out is not a problem unless you see a problem with it going up into the second floor. Can I put the studs against the foam with the Roxul, or do I nead to have something else before the insulation. I did this pic just so maybe it'll save me a thousand words :? Am I going in the right direction? Thanks. Arthur

Yeah, flanking noise can get you for sure - if you allow the sound to directly affect the concrete, the sound will travel along the concrete to other areas and vibrate whatever it's in contact with, eventually moving the air in that new location (IOW, now it's back to being AIRBORNE sound) The way to avoid this is isolated frames and inner leaves - if you have an inner mass leaf on a separate frame, then your ceiling is either resiliently hung from upper joists or resting on the inner wall frame, you've just broken the flanking path (other than the vibes getting into the concrete floor >concrete walls > upper walls > radiated into living space ) Here's an article on flanking that may be of interest - http://www.cmhc-schl.gc.ca/publications ... /96228.htm Although I think that covers more flanking from room to room due to framing if I'm not mistaken. Still, the concept is the same - you need to not allow sound to impinge on any surface that leaves the room. This is the idea behind room-in-a-room construction... Steve

Steve, let me see if I'm getting this right, from what I'm understanding from you and the link, what I need to do is build my interior walls away from my exterior walls (block and foam) by say an inch, then let the ceiling rest on top of the interior walls, correct? Do I need to put a backing on the studs for the absorbtion sections, walls and ceiling, (i.e. sheetrock or inside out wall) or will the air space do the same thing if the studs themselves arent making contact? I know my slat resinators and bass traps will have a back and be sealed airtight, but I guess I'm confused about what to do for the ceiling and walls that are just absorbing sound. Sorry I'm not getting this, I think grey matter is leaking out my ears :oops: Thanks for helping me understand this. Arthur

Steve, I think I got it, well actually I had it all along. I think it was one of those "forest for the trees" kinda thing. I added that foam at the last minute and still ain't sure why I got so confused. :roll: Once I reread my notes and the other post you offered it dawned on me the only thing I really had wrong or differant was adding that foam and it only affected that one wall, all I had to do was a little finagling to de-couple my vocal booth wall and then just set my interior wall 1" inside the foam instead of the block, which I intended to do in the first place, then use my RC mounted sheetrock for my ceiling. I think that puts me back on the right track. If you can understand what I just wrote, maybe you can double check me. I really appriciate all the effort you've given to help keep me straight. Thanks again. Arthur

Arthur, my brain's a little too fuzzy to think like myself right now (cold medications) much less think like someone else; maybe this drawing will help clear up the isolation vs. good sound concepts... Steve

Steve, sorry to hear about the cold, ragweed's been wearing me out :cry: Thanks for the last post and sorry mine was kinda convoluted. I have a quick question about a wall construction, I'm in the position while I'm still framing to set up a small closet for a "just in case" booth. Can you tell me if this construction methed will work , two inside out walls with absorbtion back to back, IOW studs filled with insulation, 5/8 sheetrock, air space, 5/8 sheetrock, studs filled with insulation, cloth over both sides of insulation. I'm not looking for total isolation just trying to sqeeze as much space as I can in a small room without too much leakage. Thanks again. Arthur

That will sorta work, but if you can also put insulation BETWEEN the wallboard (semi-snug fit) it will improve damping in the wall and should improve iso by anywhere from 4-8 dB - of course, the wider the air gap between the two areas of wallboard the better isolation also... Steve

you wrote "broadband absorbers OR slat absorbers for larger room". What is the diff between the two, and what size rooms do they apply to?

Differences - slat absorber, slot absorber, and perforated panel absorber are all names for various types of Helmholtz absorbers, named for their supposed inventor - they are all resonant traps, and as such have a fairly narrow bandwidth for absorption - there is a spreadsheet for their design located at the top of the Acoustics forum; it's corrected by me with the right formula (most on the net are WRONG) and John enhanced it for use with both metric and inch units. The slats/slots and cloth in front of a sealed, fiberglass absorbed cavity is what makes them tunable; with just the fiberglass, they become a broadband absorber that doesn't absorb to as LOW a frequency, but has a wider range of effectiveness. The smaller a room, the higher in frequency its resonant modes will be; the lowest dozen or so of these are always spaced too far apart to just "blend together", so to speak. Because of this, these lowest modes can be easily percieved as peaks and nulls in frequency response. The larger the room, the lower all these modes are in frequency; when you reach a large enough size, all the wider-spaced nodes are below the audible range and modes cease to be audible. Very few of us on this board will have the $$$ to build rooms large enough that this happens; I'm temporarily out of time for now, but I'll post a wrap-up on this either later tonight or tomorrow; if for some reason I forget I said that, please "bump" the thread and remind me; this is an important topic that's not been covered here much... Steve

so, what you are saying is that when i treat my 12x20 foot room, i should skip the slats on the side absorbers as shown by John's plans and just build them with a cloth face.

No, the side absorbers are fine; their purpose with the slanted faces is to redirect early reflections away from the mix position WITHOUT deadening the room more than necessary. The only change I'd make is to make EACH one 4 feet wide with ONE continuous angle, and 10-12 inches difference in depth across that 4 foot span - this will work better to kill the less audible effects of flutter echo, and still act as a part of your RFZ for mixing. If you take another look at that drawing, you'll see that I only said that about the rear corner absorbers; the front corners still need broadband absorbers (no slats) in most rooms If your room is 20 feet long, you're getting close to being able to use diffusion at the rear (or V-shaped slat absorbers) if you want the room brighter - generally it's only recommended when you can have more than about 12 feet from the back of your head to the back wall; less than that, and the sound doesn't really get diffuse enough not to still have specular reflections, which make head positioning pretty crucial... Steve

So I should make the front corner traps with just a cloth face? Does it make any difference if drums will recorded in front of them?

bump

Drums generally do better in their own space that can be tailored more to their needs; for example, tuning a fairly large slat resonator to 300 hZ in a drum room is almost always a good thing; that's the shell resonance range for 22-24" kick drums, so that 300 hZ trap will help keep the kick drum from exciting room modes at that range. If the room is multipurpose, you need to stay away from narrow band treatments like slats and panel resonators, unless you have enough room for several that are tuned differently. When in doubt, I would stick to more broadband treatments... Steve