Layering thinner panels = equivalent thicker panels?

Posted: Mon Apr 21, 2008 8:09 am

A semi-local wholesaler is selling surplus Roxul AFB at a bargain, albeit in 1-inch-thick panels [1" x 24" x 48"]. Will the ratings for four (4) 1" panels affixed to each other (twine, glue, etc.) be identical to how Roxul rates its 4" panels?

Posted: Mon Apr 21, 2008 8:15 am

AFAIK, layering the the same product is additive, yes.

But IMHO to be cost effective, the 1" should be less than 25% of the cost of the 4". That way, you'll be making up for the extra effort to deal with the 4 times the amount of work it's gonna take to hold all those layers together.

I'm not saying it's not worth it though.

Posted: Mon Apr 21, 2008 8:27 am

Thanks, Max. It's close to 25%: they're selling twenty-four (24) 1" x 24" x 48" panels for just under $20, versus a well-known etailer's price of 6 panels of 2" x 24" x 48" for $36. Do you think it's worth the headache?

Posted: Mon Apr 21, 2008 8:53 am

You don't really wanna know my opinion... but since you asked.... (hehehe)

I don't mind doing the extra work. Then again, look at what all I'm willing to do for a studio...

I'm obviously insane, so take that into consideration.

Posted: Mon Apr 21, 2008 10:50 am

You're living my dream, brother.

Posted: Thu Apr 24, 2008 4:46 pm

Seems like a good price to me! $0.83 per 1" panel vs. $3 per 1" panel right?

The other day I paid $1.50 per 1" panel of Roxul Safe'n'Sound, which has the exact same NRC rating as AFB iirc. I think that was a great price. I bought it in 3" panels, which I'll be doubling up to make twenty 6" panels.

Posted: Thu Apr 24, 2008 6:22 pm

A little under $.80 per panel, yeah. I was so excited to find the ad. I haven't hardly been able to sleep these past 3 days because of it. I bought 96 panels in all to make a total of sixteen 6"x2'x4' panels.

However, I'm not sure if it's reacting how I thought it would. I haven't finished all the panels nor put them up in my rooms yet, but the fact that having all that insulation in my van in transport didn't make a big difference in how my stereo sounded is bemusing.

You were smart to buy smaller quantities of thicker panels. To fit 6 at a time into the fabric "pillowcases" I made was a chore. The question of whether the acoustical properties are additive, as thought, is still kind of haunting me. I'll post my results once I find out.

Posted: Thu Apr 24, 2008 11:27 pm

Patrick while im no where anywhere authorized to say this but I do believe that most car's are very acoustically sound. I've heard countless stories of people recording amplifiers in their cars. I listen to my mixes really carefully in my car stereo (but thats also cuz it includes a built in 3 band parametric eq there too so i took a frequency analyzer and a cd of pink noise and got it all nice and amazing in there!) ANYWAY

So i think adding extra acoustic insulation into something that is already pretty well acoustically treated wouldn't change anything, Ive gotten my hands on tracks from contests and added my own eq and junk and heard about no difference in sound which made me mad jealous!

Anyway its late, congrats on your find!

Posted: Fri Apr 25, 2008 10:20 am

I also wouldn't expect to hear much difference in a van. It isn't until these things are well placed in a large open room that they should make a difference.

I should mention however, that right now I have 5 bags in my room (each containing 8 compressed 3" panels). I stacked them in the corners and then proceeded to play drums. The difference surprised me - CLEAN LOW END! My kicks sound much tighter now. Even the snare sounds better. Definitely the direction I want to go in. I actually feel like a better drummer now, because my drums sound better! Very exciting!

I can't wait to have these things hung around my room! Twelve traps will handle corners alone (including wall/floor and wall/ceiling). Two for reflection points while monitoring. Six for my two broad walls 13' apart to trap bass as well as absorb higher frequencies to avoid phasing issues in drum overheads (which is a big problem for me right now, cymbals sound like crap in all my recordings). There will be no traps on the opposing walls that are 21' apart, so I should still get a little ambiance in the room. I may build some diffusors later to further improve this if it is necessary.

Now to track down some wood. I have a pretty clever idea for making frames for these traps that will not only support the insulation, but minimize wood needed (and therefore minimize cost/maximize absorption too) and make them fit perfectly in DIY Ready Bags with defined square edges (no sagging anywhere). It's going to look and sound great. 20 6" traps for like $50 each (the bags are the expensive part)!

Posted: Fri Apr 25, 2008 5:03 pm

patrick_like_static wrote:

However, I'm not sure if it's reacting how I thought it would. I haven't finished all the panels nor put them up in my rooms yet, but the fact that having all that insulation in my van in transport didn't make a big difference in how my stereo sounded is bemusing.

I'm with you, seems like reducing the vans overall cubic volume would have made some sort of difference.

Posted: Thu May 29, 2008 7:23 am

Patrick,
I 'spect the real benefit will be in low-end/standing wave supression, right? If you have much low end in a small space it's from shear power as opposed to destructive/constructive reinforcment.(I would expect little effect from absorbtion). I gotta try some of this stuff!
And you're sitting in your van so there's no standing waves...

Wink

This topic sponsored by: