R/E/P Community

R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: marcel on February 16, 2011, 10:53:10 PM

Title: Ceiling treatment / traps
Post by: marcel on February 16, 2011, 10:53:10 PM
Hi:
I hope I can get in under the wire here...  I also hope you all can bear with a bit of explanation:

I have a small overdub studio attached to a larger facility.  There is a control room and a tracking room with good separation, tie lines, etc.  Purpose built by professionals (used to be Little Mountain).  The tracking room is about 15'x16'x9'-6" high, with a carpeted floor, continuous wall paneling (2x2 frames with fabric stretched over, filled with some sort of insulation) covering donnacona board instead of drywall, and an 8' dropped ceiling (regular T-bar and acoustic tile) covering an open joist, insulated ceiling.  I think the ceiling is an elegant and cost effective way of dealing with the problems of a small, squarish room (designed, according to my conversations with previous owner Bruce Levens, by the late, great John Vrtacic).  The insulated joist cavities are 'natural' LF traps, and the T-bar and tile makes everything look reasonably presentable and provides additional damping and filtering.

However, we are currently experiencing some conflicts with the VO studio upstairs (I know, I didn't design the place) which are forcing us to consider (multi-layer) drywalling the interior of the tracking room in order to prevent bleed into adjacent areas.  In order to do so, we will have to remove the T-bar ceiling, the wall paneling, the carpet, etc.

I'm pretty scared to let a room this small and square have any acoustic properties other than 'totally dead'.  I intend to rebuild or duplicate the wall panels and to gamble on replacing the old carpet with cheaper and easier to clean laminate flooring (we can always throw down a rug if we need to), but I'm a little unsure as to what to do with the ceiling.  There are a couple HVAC 'items' in the drop that make me want to replace it, but the acoustic tiles will have to be swapped out.

Would 1x2 frames, stretched fabric, and some sort of 703 analogue in place of the ceiling tiles created an effective 'dead' trapping space, or would the drywall above have to be covered with something as well (and perhaps fitted with corner traps)?

Should I lose the drop (I can live with a few visible vents) and just try to treat the ceiling itself?

Our budget for the reno is to be as small as possible (it's not my dime), but I have spent many years in the construction industry and can build most anything needed if the cost of materials isn't prohibitive.  I would rather build than buy, I guess.

Any ideas are appreciated.

Thanks a bunch.

Best, Marcel
Title: Re: Ceiling treatment / traps
Post by: franman on February 17, 2011, 08:04:29 PM
Hey Marcel, Thanks for posting.. I'm not exactly following the question, but I do likely agree that (with a few exceptions) in a small, too square room dead is probably the way to go.

If you are asking what would the equivalent of the dropped tile ceiling be regarding absorption, then a 2" 703 board in a similar mounting (meaning with a captured air-space behiind) would provide at least as high of an absorption coefficient.

I might suggest 2x4 wood framing the ceiling 24"oc about 12-18" below the (new) hard shell top.. They friction fit 4" of Rigid Fiberglass (703) into the framing and loosely fill the space behind with unfaced batts...Cover the whole things with stretched fabric. This is a low budget broadband LF absorber used in many rooms... Hope this helps.

FM
Title: Re: Ceiling treatment / traps
Post by: marcel on February 17, 2011, 09:28:12 PM
Thanks Francis, I think you pretty much nailed it (hey, I knew what I was talking about, LOL).

I was looking for a solution that replicated the broadband LF absorption of the open joist/insulation assembly once the joists had been covered up with sheetrock.

I discovered some others' experience with solutions that were basically identical to yours.  They actually stuffed the loose batts in above regular 1" acoustic ceiling tile, which I may do if I can get the T-bar down and back up without damage.  Purely a cost-driven decision.

Thanks again.

Title: Re: Ceiling treatment / traps
Post by: franman on February 18, 2011, 07:34:18 AM
that will work also.. good luck.