My first attempt at controlling room acoustics

spantini

COO of me, inc.
I have a small budget and need to build some portable panels for use in my small efficiency.

I've seen lots of posts here about rock wool and fiberglass insulation usage for controlling acoustics in reflective spaces. Further reading mentions dust problems with wool and, of course, fiberglass strands (I'm painfully aware of the latter).

Recent posts and articles have stated kraft faced R30 fiberglass works better at controlling room reflectivity; better than rock wool. This would seem to offer some advantages: better acoustical properties; less loose material (if handled properly); lighter in weight. So at this point, I'm looking at going with the R30 fiberglass.

I can make some light-weight frames and cover the glass with landscaping material.

The only thcknesses I can find in my local Home Depot or Lowes begin at 6.25 inch and go up to 10 inches. I was looking for 3 or 4 inch, but no luck. Now, I've searched online only for this product, and I know store's websites don't always accurately reflect their inventory, so I'm going to have to make some personal appearances.

The package I see on Home Depot's site contains Qty: 11 - 24" x 48" x 6.25" sections. That's a decent amount of coverage to start out with, and 11 individual panels will make for very flexible usage. One package of this R30 and one roll of landscape fabric will run about $80. Economical enough for me.
 
I can't understand why you'd prefer fiberglass bats to something that is known to work better. Maybe I missed the post but has there actually been any long-term study of people working in rooms where this material is simply covered up properly that shows negative health effects? I mean, it's not asbestos, and they do sell it at my local Lowes...

I've got 20 3.5" rockwool (Roxul Safe'n'Sound) material in 4" and 8" deep panels in my little room all in fabric covered frames. There's no dust, or at least there's a lot less dust, in this room that I'd begin to attribute to these panels. I probably breathe more carpet fibers and cat hairs in a day walking around (and sleeping) the rest of the house than I do in any time spent here. (The ozone laden air I breathe outside is probably going to kill me before sitting at the DAW will.)
 
I'm leaning towards the fiberglass only because I read some posts and at least one article (can't cite) which stated the R30 was better at reducing reflections than rock wool. But then, I've also read rock wool is excellent at this. So I lean towards R30 fiberglass for it's lightweight feature. I'm not concerned about their health problems as I'll be wrapping it all in material.

The dust and strands I mentioned were referred to as mostly coming from handling the material as it's being installed.

The R30 fiberglass is substantially lighter in weight - the rock wool in my area is available same day in 4-sheet pkgs of 7.25 inch thickness at about 10 lbs/sheet - I don't see any thinner sheets for same day p/u. As a starter project, I'd prefer to go with the lighter weight material, adding heaver products later as I can afford.

And.. I agree with you on breathing in more crap around my apartment and building than these would give off.
 
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R-30 is that thick as it is made for attics and craw spaces. Just so you know, using pvc pipe for frames and moving blankets will do the same thing you want to achieve. They are non reflective and they will give you the absorption you need. Quilts work great as well and they will look nice in the room.
 
Hi, Mack.

My reasoning is... the 11 separate batts of fiberglass I could frame and wrap - I would have more flexibility in arranging them as opposed to 2 PVC stands and blankets (for about the same dollars).
I was going to get some heavy cardboard material to make the frames, with the landscaping fabric wrapped around to make it more rigid as well - enough to permit stacking on edge.

When I get more money, I can add the PVC and blankets and have both. I'm not going to go with one only.
 
OK, ...I'm not asking you to Believe....just to think and try.

Take five or more bathroom towels and layer them on top of one another. Have someone hold them up and talk through them. Have maybe a mic on one side and a speaker offering a frequency sweep on the other side. The different weaves and slight air spaces between the layers, IMHO, works amazing. I made five panels (2 x 4 feet, with 25 to 30 towels each) and placed them strategically, and the echos and highs are all contained. For the bass, I filled hanging cloth shelves (the kind that hangs on a closet bar) with as many folded towel as you can jam in there. I hung one in each of two corners, about 10" from the corner walls. My room sound great with consistent -80dB of noisefloor. BTW, one panel covers a window too. Quiets outside sound.....just sayin'
 
Yeah, but you had a big windfall of towels. To actually go out and buy that many towels...

I have a bunch of my kids' old clothes and fabric that I've collected that I keep in bags in the corners of my mix room. They're kind of hidden behind chairs, but I didn't try all that hard, so it looks like clutter but actually it's bass traps. :)

But again, that's stuff I had around. Fiberglass is a hell of a lot cheaper if you have to go buy something.
 
I have a small budget and need to build some portable panels for use in my small efficiency.

I've seen lots of posts here about rock wool and fiberglass insulation usage for controlling acoustics in reflective spaces. Further reading mentions dust problems with wool and, of course, fiberglass strands (I'm painfully aware of the latter).

Recent posts and articles have stated kraft faced R30 fiberglass works better at controlling room reflectivity; better than rock wool. This would seem to offer some advantages: better acoustical properties; less loose material (if handled properly); lighter in weight. So at this point, I'm looking at going with the R30 fiberglass.

I can make some light-weight frames and cover the glass with landscaping material.

The only thcknesses I can find in my local Home Depot or Lowes begin at 6.25 inch and go up to 10 inches. I was looking for 3 or 4 inch, but no luck. Now, I've searched online only for this product, and I know store's websites don't always accurately reflect their inventory, so I'm going to have to make some personal appearances.
..snip]
You should be thinking of comparing density (weight LB/Ft) ..and depth.. the most important in extension into the low end, along with sq ft of coverage.
http://www.bobgolds.com/AbsorptionCoefficients.htm

I used the readily available 'fluffy stuff (probably the same, 3pcf?) and compressed it -probably by half? in my gobo' / 'sectional panels.
But again, final depth 'rates -generalizing, stronger (in the lows) than 'PCF.
 
Roxul Safe'n'Sound has a density of over 3x R-13 wall insulation (40kg/m3 vs 12.1kg/m3). So, if you want to compare cost, it's not a cost savings, since, locally at least, the R-13 stuff is about 1/2 the price, but you'd really need more than twice as much. And then, I doubt seriously if you could pack 3 layers of the R-13 into the same thickness, so your framing cost would go up. So it's going to cost more both in material and framing for the same density.

Now, if you cannot source the mineral wool locally, maybe 2x layers of R13 might work in a pinch, but that's going to be pretty uncomfortable working with that much fiberglass, especially if you're trying to compress it and hold it in place.
 
I'm looking at faced R30 batts 9.5" thick x 24" x 48". I would be wrapping each batt with black landscaping material.

Would compressing these to a 4" or 5" thickness hurt the acoustical properties I'm going for? Should I leave them at 9.5".. ?

1-Pkg of 11-batts is around $60 - not too bad on the budget.
 
I built three- 4'x 61/2' in thin backed frames so they could be movable or stand alone. But wire and the fabric taught across them to contain the compression.

Would compressing these to a 4" or 5" thickness hurt the acoustical properties I'm going for? Should I leave them at 9.5".. ?
I don't know but I doubt it. Look at the 4" 125Hz 701, 703 and 705 -1.4, 3 and 6 PCF numbers. Not much variation, nor much to go on re '6 - 9".
 
I think I remember reading that you would need 18" of fluffy fiberglass to equal 4" of rockwool. IF you've got the space for it, go for it, most of us don't. Get the good ROxul or OC insulation from ATS Acoustics if you don't have a local source. It's better to save up some money, and do it right the first time rather than mickeymousing it and spending more money in the long run.
 
Would compressing these to a 4" or 5" thickness hurt the acoustical properties I'm going for? Should I leave them at 9.5".. ? 1-Pkg of 11-batts is around $60 - not too bad on the budget.

It's not the depth of the material so to speak, it is the amount of air that is trapped inside. For your purpose and the rest of the conditions you are facing within your recording environment, it will a very small advantage regardless of what you choose to do.
 
I think I remember reading that you would need 18" of fluffy fiberglass to equal 4" of rockwool. IF you've got the space for it, go for it, most of us don't. Get the good ROxul or OC insulation from ATS Acoustics if you don't have a local source. It's better to save up some money, and do it right the first time rather than mickeymousing it and spending more money in the long run.

I can get Roxul R30 unfaced at my local Lowes. Package of Qty = 4 : 23" x 47" x 7.25" - - That's 20 lbs per sheet.

This stuff is less expensive, performance-wise, than R30 Fiberglass , but I'll need more sheets which will cost more up front. I'll be saving for this.
 
Lighter weight. I'll want to stack them and rearrange in other ways as needed. I plan on adding Rock Wool later as I can afford it.
Well, it's not just air, so it does have some weight, but the package weight is 37.5lb, for about 3lb 2oz per batt. I've moved double thickness traps and stacked them when fitting the bass traps in the corner, and I'm a pretty small-ish, old guy.

The framing is going to be at least half the weight, and most of it in the case of fiberglas, because the frames will be heavier due to the thickness of the material. In fact, I'm curious about what the total weight of one of your R-30 framed panels is going to be. I'll weigh one of mine when I build some more later this month. (They're all fastened to the walls/celing or anchored in corners right now.)

To me, having gone through the exercise of building a bunch and hearing the effectiveness, and perhaps not having room for a lot of 1' thick panels standing all around, I'm only seeing a lot of wasted effort and money. But, I see you've talked yourself into this. Good luck.

P.S. Be careful stacking these things. They don't weigh much, but if one decides to topple, it can take out a couple mics and guitars on the way down. (Not planning to stack mine, ever.)
 
I just remembered something that was mentioned in an earlier post. The R30 faced Fiberglass I mentioned... is 7.25" thick. One layer of that with the facing outwards means the waves would travel through the glass then reflect back outward through the glass again - (theoretically) doubling it's effect, behaving like a 14.5" deep layer. For what that's worth..
 
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