DIY acoustic treatment

nice job!

LOL - I love the ghetto corner traps!!! Looks good, Jeff! I've been itching to build some myself - that's probably my next step!

Nice work! Glad you posted pics so people can see it ain't that difficult!

Corey

Flipper, Corey: Thanks for the attaboys. I think the hardest part was convincing the lady at Wal-Mart to cut the burlap into four foot sections. She didn't want to cut them individually until I mentioned how Sam Walton believed the customer was always right.

She only wanted to cut one long piece for the total length. She seemed to have trouble with the math because they made her charge by the yard.

I've tried to keep my receipts. I'll make a list and post the itemized bill soon.

How about DIY tips for rear wall diffusion?

Hmm, this has me thinking about going down the same road - thanks for the pics and info Jeff.

By the way, I liked the pic of your $90 pawn shop bass - for some reason I always see plenty of bass guitars in pawn shops I've frequented.

Thanks again :-)

Corey:

I used Bonded Logic Ultra Toch

http://www.bondedlogic.com/ultratouch.htm

I came across it via one of Beagle's links and it has an acoustic coefficient equal to 703/705.

It's made from recycled denim and is more user friendly.

Corey: I've got half the panels up and haven't put the room back together yet, but I can really hear the deadness just singing and playing gtr in the room.

I'm gonna need to build two more to get floor to ceiling coverage in the rear wall corners. Then I've got to do something about rear wall diffusion.

Will probably be a week or so before all is back together and I can get a good feel for the differences.

Lance: Thanks. I've yet to get up and running, but I hope to be ready this weekend to give the room a test drive.

I've got band practice on Sat afternoon and my first solo acoustic performance in 10 years on Saturday night.

I am excited about the 80s. Much better than the crap I have.

Here's an absorption coefficient set of tables to help you with your decision on which types of materials to buy or DIY Bass Traps.

http://johnlsayers.com/Stuff/AbsorptionCoefficients.htm

the Ultra Touch isn't listed on these tables, but here's a link to the ultra touch's Abs Coeff:

http://www.bondedlogic.com/documents/InsulatorSpecSheet.pdf

Notice that the ultra touch has the following coefficients for 3/8" layer:
125 - 0.12
250 - 0.10
500 - 0.23
1000 - 0.56
2000 - 0.81
4000 - 0.89
NRC - 0.45

for 703 (per the table on the John Sayer website) for 1"
125 - 0.11
250 - 0.28
500 - 0.68
1000 - 0.90
2000 - 0.93
4000 - 0.96
NRC - 0.70

NOTE: doubling the thickness of any of the acoustic materials does not double the coefficient, but it DOES increase it and it's not unreasonable to believe that 2 layers of the 3/8" Ultra Touch would easily be at least as good as the 1" 703. (However, most people use at least 2" 703 for bass traps, so one would have to have at least 4 layers of Ultra Touch to match or exceed (possibly) the 2" 703).

Also notice that 3/8" if Ultra Touch is MORE effective at absoption as 1" of 703 for 125Hz and certainly doubling the layer of the Ultra Touch would be even greater of an absorption at that range!

Ah - that's an excellent coefficient table set as well!

good deal - glad that worked out well for you - if you left it doubled, then you're probably getting close to the 5.5" numbers!

ORIGINAL: jsykes

Beagle:

The insulation I got was R13 at 3.5" thick. The coefficient is listed on this link near the bottom:

http://bobgolds.com/AbsorptionCoefficients.htm

I came across it via on one of the John L Sayers links:

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5928


I just left mine doubled because:

1. It was easier than cutting it and making a mess.
2. It was already flattened somewhat and the double fit nicely in the 1x3" pine board

Oh my god. You do not know how long I have been looking for something like that first link! I never seem to be able to get ANY details on specific frequencies that are absorbed from Australian insulation manufacturers! This has many! And has the exact brand I was looking at the other day! This page was INSTANTLY bookmarked and if we were at a Pub right now I would buy you ten beers!

Jeff,

I got my R-13 which is supposed to be 3 1/2" but it feels and measures more like 2 1/2". Does this stuff "expand" over time? I just opened the package and made two frames of 1" x 3.75". Seriously, it feels like I could double layer this stuff inside my frames.

Also, there is a ruff side and a smoothe side. Which side did you have on the visible surface of your panels?

TIA for your help.

a smooth/rough side

I was referring to the R-13. It has a rough(pourus) side and a smoother side. I elected to make the pourus side the "front".

I made two panels for my "cloud" (above the mixing position) yesterday. Will hang them either tonight or Wednesday night. Then I'll make my side mixing position panels and then measure my room before making any more.