Isolating Exterior Noise (Ceiling)

[stettoman]

Wow, is THIS an under-utilized forum...

I'm kinda looking for a second opinion on isolating exterior noise from a living room above my under-construction home studio. I've started a thread at John Sayer's forum and have gotten excellent advice from Stuart there, but I want to explore options and he only gives me one: decoupling.

The room is for all intents and purposes a blank slate. I have open joists, cinderblock walls on three sides, am mapping out an 8" staggered-stud wall for the fourth.

The room is (for the moment) a rectangular 20' (19' 9") X 13' box with an approximately 6' 9" ceiling (floor to joist timber). A ceiling that low will not accomodate a lot of build-up, but it is the one surface of the room I need to focus on. It's the only part of the room transmitting noticeable noise. I'm hoping to be able to get away with a modified system.

I had read at the Auralex site that IN FLOOR APPLICATIONS their Sheetblock product can be cut into strips to line the tops of floor joists prior to installation of sub-flooring. Can this be effective as well on the ceiling (using rigid fiberglas)? I would follow with 5/8" rock, 1" firring, another lining with the rigid on the firring and 1/2" rock...The joists of course to be filled with rockwool....

I already know that I can't, without tearing out the floor above and rebuilding joist, subfloor and such, eliminate ALL the noise. The house is just too old and poorly built in the first place. But it would be nice to minimize the sound of the kids, dogs, cats and Mama's Dyson traversing the space above...

All on a 0$ budget

Thanks

[Ausrock]

Stetto,

John's forum IS the best place to get answers........unfortunately, sometimes the answers aren't what we'd like to hear :-).

I faced a similar issue some years ago when I was trying to improve the downstairs studio, I ultimately gave up worrying about the ceiling for a couple of reasons..........to successfully isolate "up from downstairs" was going to use up limited studio headroom, thereby affecting the acoustics of the studio......I chose (limited) acoustic quality over sound isolation. The only idea I had that wouldn't chew up headroom was going to be a compromise and meant ripping out the existing ceiling and spending considerable dollars that I didn't have at the time. I don't know the depth of your floor/ceiling joists, (mine are 8") so this may not be of any use.............The idea is/was to make the ceiling from panels that fit up between the joists sitting on timber "rails" attached to the joists, the rails would have a neoprene strip on their top surface for the panels to sit on and the void above the panels would be stuffed with rockwool. I had intended to make the panels from fairly thick MDF for mass but there are other products now available that would do the job. A couple of thoughts I had at the time were that the section of the joists extending below the ceiling panels may help acoustically by diffusing some of the soundwaves and there was the option of angling the panels so the ceiling was not parallel with the floor.

I don't know if that has made sense but I hope so ........lol. You can see pics and a bit of a story about our studio here http://www.recordingproject.com/bbs/...ic.php?t=30325

Cheers,

ChrisO

[stettoman]

Hey Chris

Thanks for chiming in. Yeah, I got the impression pretty early on that the JS site was the end-all, but like I say I'm interested in some DIYer input that may (and may not have) worked for some that might have got by the specialists. Info I'm getting at JS is obviously inarguable, but I just don't have the headroom to spare. I don't want to have to take more than one swing at this, so what I end up with I'm going to live with, better or worse.

Diffusing the existing joists is an obvious consideration that never occured to me (though it was always a plan to stuf a lot of mass between the joists), but now that I think of it I can visualize just what you say. My joists are only 6", but if I construct "baffling" like one of those Se reflection screens, using differing thicknesses of medium like hard and soft foam, rockwool and good ol' pink fiberglas (soundwaves HATE transmitting through varied and different medium, heard that at the JS site, wink-wink), I have the opportunity of testing effectiveness as I go, and still have the option of adding something to the joists (three layers of 5/8" ferinstance) if the noise reduction isn't sufficient...Bracing between the joists to correct shifting would be easy as well...

...And yeah, mass, masss, mass....

By the way, checked your thread. I noticed there is no "last chapter". One of the things we did to manage moisture in the studio area was to install interior drain-tile. The cinderblock walls that were soaked 1/3 up to the floor dried up in two days. Well worth the $4200 investment...

[Ausrock]

I'm attempting to attach a rough sketch of what I was suggesting, hopefully it will be self explanatory . If the panels are made from two or more layers of different materials (eg; MDF, Gyprock....ie: wall sheeting, etc) then you achieve mass and inhibit the transfer of vibration, add as much rockwool, etc., as possible on top and you may be getting somewhere. Isolate the panels from the joists and support rails with neoprene and rely on the mass/weight of the panels to hold them in place and I don't know what else you could do..................PLEASE remember, this concept was never put into practice so I don't know how successful it would have been but at the time it was the only idea I could come up with that would reduce studio noise going upstairs while retaining the limited headroom in the studio. These days, I don't have the worry as the wife no longer works night shifts.....our bedroom is above the studio .....................AND, the "last chapter" as you called it is only now coming together so hopefully I will post some pics to complete that thread in the nearish future.

Chris

[stettoman]

Ahhhh, I see. You "shelve" the inside of the joist to hold your medium, eliminating the necessity to attach by means of glues, screws, etc. Ingenius.

I would think, to hedge your bet, that lining the shelf firring where the rock, rigid fiberglas, wallboard, whathaveyou with a strip of carpet pad or rockwool or such stuff will isolate your medium from the joist and at the same time eliminate any chance of vibration against the fir strip to cause "buzz"...

That is a great idea Chris, proven or not.

As the Van Dyke-wearing Spock said to Cap'n Kirk in that old "altenate universe" episode of Star Trek: Captain Aus, I shall consider it...

Thanks

[Ausrock]

Originally Posted by stettoman

I would think, to hedge your bet, that lining the shelf firring where the rock, rigid fiberglas, wallboard, whathaveyou with a strip of carpet pad or rockwool or such stuff will isolate your medium from the joist and at the same time eliminate any chance of vibration against the fir strip to cause "buzz"...

Yep, that's what I meant about using a Neoprene strip/cushion under and around the edges of the panels........the thicker the Neoprene, the less vibration is transfered. I would think that even if you sparingly screwed through the "shelving strip" into the panels, the level of vibration transmitted would be not much different to having no securing screws.

Also, as I said, this gives the opportunity to angle sections of the ceiling which can only be of benefit to the room acoustics.

If I thought there was any chance of me recording other musicians on a frequent basis, I would be making plans to renovate the studio ceiling this way but real life (work), means that the studio sits idle most of the time so I can't justify the time and cost involved.

[stettoman]

"If I thought there was any chance of me recording other musicians on a frequent basis, I would be making plans to renovate the studio ceiling this way..."

As would I, but it will be almost exclusively myself and a friend, doing a lot of acoustic stuff. I have touched on this at John's site, but, well, you know...

I own around 6 acres out here, 12 miles from civilization with no threat of EVER being threatened with municipal zoning. I would eventually like to build an out-building and perhaps a more professionally designed studio will go in there, heck, maybe even some higher end recording gear as well...

[stettoman]

I suppose it might be polite to "close" this topic with a report.

With my elevation-challenged ceiling being what it is I was limited with options. I filled the joists with r-32 fiberglas (density rockwool is not only unfamiliar to vendors up here, it is impossible to buy without a sizeable freight payout). Then the majik: I lined the entire ceiling with 1/4" fanfold foam, laid 1/2" sheetrock, taped and caulked entire, laid another layer of 1/4" fanfold and followed with 5/8" rock, then normal tape & texture. It still left me with approx 6-1/2 feet of "headroom" to work with.

I'm walling off the ductwork into a storage closet/mic cab (one of the reasons I'm giving Alan hell about the SP ribbon), installed the cabs yesterday and am framing the wall as I speak. That too will be heavily insulated and foam-lined.

Actually, for not doing what was suggested I have a severely quiet room. No, I doubt it would live up to the pro's standards, but compared to places I've recorded in my life my studio is a veritable isobooth.









The window is doomed to be knocked out and blocked.

Of course, with the future always flixing and fluxing, my ultimate goal is to eventually turn this room into a guestroom and build a studio separate from the house from the ground up. This will more than do for the interim. I am a home-recordist, but I have done quite a bit of tracking for others, mostly gratis, which I'm afraid is the curse of me...

[Ausrock]

Stet,

It's good to see you persevered, the results look cool .

Like you, I'd love to move from a semi-underground, low headroom space to something more purpose built but it won't happen while I live in suburbia. In the meantime I've just about got everything functioning OK, the big plus was getting my 16 trk digital synching to my 16 trk R2R.......it's a joy to behold . Now to psych myself into some tracking.

Chris

[stettoman]

Originally Posted by Ausrock

Stet,

It's good to see you persevered, the results look cool .

Like you, I'd love to move from a semi-underground, low headroom space to something more purpose built but it won't happen while I live in suburbia. In the meantime I've just about got everything functioning OK, the big plus was getting my 16 trk digital synching to my 16 trk R2R.......it's a joy to behold . Now to psych myself into some tracking.

Chris

Glad you approve. I installed track lighting in all four quadrants of the room, in case I one day decide to divide it up, and those lights invade an awful lot of space that foreheads and tuques (sp) will one day occupy...

Digital/analog--Best of both worlds! Alas, I have 16 of digital (ok, 16 plus 8, as I also have an Alesis Blackface ADAT that still only has 20 or so hours on the drum ), but my tape rig is a 20-some year old Fostex X-26...I'd love a half-inch machine.

...And I actually have people trying to line up to do sessions (no, not likely for money...More of a "favor-owing" society we engage in), not to mention I'm about 30 songs behind in my own recording endeavors. My excuses are pretty close to all used up...