Johns Standard Control Room

probably 20% or more. somewhat hard to say but maybe it's possible to remove a board every 5 or 6? (maybe stagger the openings?)

The entire construction team thanks you. And the existing 100+ years of dessicated mouse excrement quite possibly will add to the R-value though probably no acoustic benefits.

JohnH wrote:

Would one of these concepts work better at keeping low frequency out? I realize that figure A is triple leaf. I also have no idea of the natural frequency of the existing 30x50 foot wood ceiling structure.

Not preserved: CeilingFigure_A.jpg

Not preserved: CeilingFigure_B.jpg

Figure A is not a triple leaf. It is a single frame/two sided assembly...a coupled assembly with another hard boundary below it. If you turned it 90 degrees in any direction it is the same as an interior wall in your home. You have another option of removing the existing ceiling, which while being the better option in a typical sense, your elevated status may not support it. Adding mass directly to your existing boundaries is most likely your best out in this case,. "According to the charts, 2"x12" on 16" centers that span only 14 feet should be able to easily support 60 pounds/square foot (dead load) and 20 psf live load." I think you have this backwards. But, doesn't matter at this stage. Deadload is the weight of the materials...all of them. When you add more, then this number changes. This is a static load. The live load, often the higher of the two but, it's your house, is not a static load. It concerns itself with things that are not there all the time, subject to move...furniture, people...and environmental impact. In an elevated, wood structure...it doesn't make since to develop a room in a room , if in fact this is what you are trying to achieve.

Brien, If I don't need a double wall, that would save time and money. The main objective is to keep the really loud noises from the outside world from coming in. I really need to take those sound level readings. Any suggestions or guidelines?

I didn't say you would not benefit from a double framed assembly, I suggested that in an elevated wood framed environment it is all flanking path so the benefits are hard to figure.

Brien - what we discussed was a decoupled room within a room approach to mitigate the flanking as much as possible to solve an issue due to low frequency rumbling from trucks. The question at hand is the ceiling with an enclosed air space potentially being a third leaf effect and how we might relieve the air spring on the upper section. Then adding the mass layers in existing and new inner ceiling, inner ceiling resting on decoupled wall frames, and a damped floor inside. Not ideal but should be reasonably effective given budget and time.

First off, I appreciate the help very much. This is a real gift that you give and I am grateful. Our plan was to carpet the multipurpose room to dampen the footfall noise adjacent to the control/tracking room. Not ideal for a studio live room, but that will probably be a rare useage of the multipurpose room. Once the control room is done, I can focus on the deck below it; add insulation from underneath, RC and sheetrock. There's plenty to do meanwhile with the rest of the building and time to finalize the design. I'm impatient as everyone is, but old enough to know better and will take the time to do it right. And you guys will probably warn me (if I give you a chance) before I do anything dumb. Thanks

I appreciate that Glenn, and your work here. Low rumble in a wooden structure works because it is moving the structure. If another assembly is built, even enclosed room, doesn't the same low frequency rumble still have ability to vibrate the structure, hit all the flanking paths/windows/openings, and pretty much negate what we tried to achieve? Rc/clips/hat track on the walls and ceilings...I know, less than ideal to reiterate and a loss in low frequency isolation, but wouldn't that actually allow a better opportunity at making the existing paths decoupled? And this might be one of those areas where green glue would be a big help to gain back some of what is lost by this attempt...not that I know if that stuff is any good or not, but if it is...this would be a place to use it. In an upstairs wood framed room, the low frequency actually has more time to develop across more wall area and create more vibrations...it's always shaking stuff. Would it be better to go ahead and take the existing ceiling down, rather than attempt to make holes?

And...if the ceiling is complete...the walls are...?

agree, the existing wooden structure will / is the main source of vibration so trying to decouple from that is about all you can do even if you can add additional mass to the existing structure to help reduce its natural resonances.

A few questions. 1. Sources for the neoprene? Any substitutes? 2. Is there any negative effect (double walls) if the outer wall is 2x6 construction and the inner is 2x4 or vice versa? Is it better if they are the same materials and mass? I'd like to have a 2x6 wall under that old ceiling beam. 3. Also thinking about the need for drapes for acoustic accuracy over the one and only sliding glass door (left of mix position) and wondering if the concept in the drawing below would work? Partially splayed walls and no glass to the right of mix position. The inside dimensions would be approx 12' x 17' with 8' ceiling Update: We're insulating the attic tommorow (Feb 15) Dragging a 300 pound insulation blower up 3 flights of stairs was fun. Had to shovel 2 feet of snow off part of the barn roof. The phone lines were buried in them. Ahh.......life in Vermont.

the room design you show is workable in that space. you can use a heavy drape over the door when needed. you can use 2x6 instead of 2x4, in fact using the 2x6 is probably the better approach overall. for the isolators, check out Mason Industries ND-A black http://www.mason-industries.com/masonin ... pdf/ND.pdf or NPS http://www.mason-industries.com/masonin ... si21v1.pdf. otherwise something like 3/4" neoprene 30 hardness strips between the runners http://www.rubbercal.com/Sponge.html 4119-N Closed Cell Neoprene

I had hoped the drapes be eliminated? Thanks for the info.

you can try it without the drapes but as a general rule less reflections in the mix space the better, if you angle the doors, then it may not be needed.

So if we frame it something like this, with one 5 foot sliding glass door....and treat the sealed room afterwards, would there be any problems? Any suggestions?

nope, i think that will be a great first start.

It is an elevated wooden environment. I have a wooden table in my kitchen and whenever drinking buddy slaps his beer onto the table...I feel it second but hear it first...actually it is difficult to tell which happens first. That wooden table is your floor. Room in a room is not the voo-doo treatment to cure all ills. An elevated structure requires far more than what you seem to be bent on with this build. Now you can move forward thinking that you are doing what is required, but you are working on information that applies to an earth damped structure. Everything, and I mean everything you do...in this build, will attache it right back to itself...completely removing the benefit of higher isolation...costing you more and have you thinking you have a better spent monies...and you will not.

Brien - the inner room is the isolation walls and decoupled and the floor is a damped membrane. without the ability to add a cement floor or restructuring the building what other options are there for this? ideally, rebuilding the floor as a completely isolated and massive structure for the room to sit on would be best but not in the budget...

If I were Joe Rock Star, I'd might have the budget to ..............., I'd move to Maui, why would I want to do this in poorest part of Vermont. I just happen to have a 2 and a half story 30'x50' building attached to my house and I'd like to move my recording equipment out of the cramped bedroom. The deck we built is isolated farely well, not touching the old existing walls or the adjacent decking, and it is sitting on a brand spanking new, rock solid 10' feet below the road, concrete foundation. It won't be perfect but it will be good enough for me. If not, I can hit undo and hit re-record. No biggie. Brien, you are right. If this were a pro studio.............if it were a pro studio, it wouldn't be here in the first place. External acoustic noise is my biggest issue. Flanking noise within the building is not. There are only 2 people living in this this third world mansion. As I stated earlier, I'm not willing to give up my garage below. It's fricking Vermont, 8 months of winter. Parking the car inside my first priority. Anything will be better than what I currently have. The boom truck came with the first load of sheet rock and 2x6 lumber which we unloaded directly onto the 2nd floor though a window. We spent the day installing the first layer of 5/8" sheetrock into the pockets between the studs of the north wall using copious amounts of acoutical caulking. Can actually hear the difference already. I've been taking photos and will post soon. But I quit for the day, its been a long week of construction and we're all covered in white powder, (NOT the kind that rock stars use OR the kind that scares politicians in the US)

Here are a couple of photos showing the north wall with tongue and groove removed and 2 layers of sheetrock with acoustic sealant in every nook and cranny. Interesting framing from previous owner :roll:

almost artistic in its own right... soon to be covered up with itchy insulation... :twisted:

Very itchy. Does it help if I scratch?

Glenn, those Mason isolators look like they're only for steel framing. Is the Rubbercal 4119 what you recommend under the wood frame plate for isolation on the inner walls? Should the plate be attached with a couple of small lag screws using rubber isolating sleeves, and cushioned washers? (edit: additional question) Also the Rubbercal 4119 specs state: Compression Deflection (25%) 5 – 9 PSI I estimate we will have only 2 psi between the plate and floor on the long walls (which will support the inner ceiling as well. (2 layers of 5/8" sheetrock on inner walls and ceiling, 2x4 wall framing, 2x6 ceiling framing, 12"x16" approx inner room size. Are my numbers off?

ND isolators can be used for wood framing. agreed, the 4119 is designed for 5-9psi for 25% compression. you could call the vendor and see if they have something for 3-5lb/in2 which would be more optimal. i have also found the folks at Monmouth Rubber Co. to be responsive and helpful but they don't do direct sales.

Thanks Glenn, Also not having any luck getting Voxengo Span to appear in Audicity's menu's. I have Audacity 1.2.6 on a windows laptop. Downloaded the lastest SPAN for windows 32. Unzipped it into Audacities VST folder. Searched the net for solutions........no luck. Does anyone have a solution. The goal: Use the laptop (with the radioshack soundlevel meter...for now), to record and analyze the noise to identify the predominant peaks in the spectra.