Bass Trapping Material: What about this one?

[Mr. Dreq]

Hi!

I've read most of the threads about the glass or rock wool material one can use for bass trapping. Unfortunately I can't find the exact stuff posted from eg Isover from other countries. So I have to ask you what product I should get! On our Austrian Isover site I have found these:

http://www.isover.at/index.php?id=24...=74&no_cache=1
http://www.isover.at/index.php?id=24...=73&no_cache=1

I'd like to know how much kg/m³ they are, but they don't tell the density :(

What do you think?

Maybe someone knows alternatives from other companies?

Markus

[Scott R. Foster]

Knowing the density and base material [fiberglass or rockwool] is the key to picking the product... call the local distributor and find out. Also, my German is rusty, but I think this stuff might work

http://typo3.isover.at/index.php?id=...=28&no_cache=1

[matt thomas]

in the "Produktdatenblatt" it lists the "Anwendungsgrenztemperatur"

the stuff I use (which is the right stuff) has a temperature rating of 450 to 650 degrees celcius

the first stuff you linked to is only 200 degrees so it is probably not dense enough, but I didn't look at the others

my german isn't good either

narco

[Mr. Dreq]

Thanx for your infos guys!

I have contacted my distributors and got these data:

Rockwool (I don't like the size of 1000x600mm, I prefer 1200x600):

Termarock 50 = ca. 55 kg/m3
Termarock 100 = ca. 110 kg/m3
RP-XV = 160 kg/m3
RP-X - ca. 90 kg/m3

Isover FDP: 50kg/m³

Heralan FP: 55kg/m³


The ones between 50 and 55kg/m³ are relatively inexpensive and the questions are:
Is 50-55kg/m³ enough?
If yes, should I go for rock or glass wool? How much difference would it make?

Markus

[bpape]

If you go with the 50'ish kg material, just go a bit thicker. Kind of like using 6-8" of 703 instead of 4" of 705.

Bryan

[Mr. Dreq]

Well that sounds good!

I have now narrowed it down to 2 choices:
4" 100kg/m³ or
6" 50kg/m³

They will be implemented in a small 4x3.3x2.5m room and I can get 20 of them if needed.
Because of the small space I would prefer the 4", but if the 6" will be acoustically better, I will get them.

[Scott R. Foster]

6" is is very nice... but 4" of +/-50 k/m3 rockwool will be fine [and much more efficent per unit cost].

Check out the Roxul Rigid categories for 4" / 100mm panels - don't get drawn into the density = performance myth.

http://www.bobgolds.com/AbsorptionCoefficients.htm

Product thickness density 125hz 250hz 500hz 1000hz 2000hz 4000hz

RHT 40 4" (100mm) 3.5 pcf (56 kg/m3) 1.07 1.01 1.07 1.06 1.07 1.16


http://www.roxul.com/sw16796.asp

[tomdarude]

hmm...confused:


Freq in Hz : 125 / 250 / 500 / 1000

703, FRK 4" 3.0 pcf (48 kg/m3) 0.88 / 0.90 / 0.84 / 0.71

705, FRK 4" 6.0 pcf (96 kg/m3) 0.65 / 0.52 / 0.42 / 0.36


actually the 50kg/m3 material outperforms the denser one ???
so around 50kg/m3 is the perfect balance for the focus on basstrapping?

ethan ??
glenn ??
scott ??


I´m building traps at the moment, so your opinions would be a great help!

tom

[Cojo]

Originally Posted by tomdarude

hmm...confused:


Freq in Hz : 125 / 250 / 500 / 1000

703, FRK 4" 3.0 pcf (48 kg/m3) 0.88 / 0.90 / 0.84 / 0.71

705, FRK 4" 6.0 pcf (96 kg/m3) 0.65 / 0.52 / 0.42 / 0.36


actually the 50kg/m3 material outperforms the denser one ???
so around 50kg/m3 is the perfect balance for the focus on basstrapping?

ethan ??
glenn ??
scott ??


I´m building traps at the moment, so your opinions would be a great help!

tom

If you see the trend - the 705 is beeing greater the lower you get while 703 is getting weaker.

Now imagine at 50 hz.

/Cojo

[bpape]

Hence my suggestion for 6" of the lower density material. It's still 25% cheaper than 4" of the denser stuff, will perform better at 125Hz, and as good or better down lower.

Density or not, there are some things that can only be dealt with via thickness and getting more of the wave in the absorbtion.

Bryan

[Mr. Dreq]

Ok, now I'm also getting really confused!
Well, would 6" high density (100kg) material perform better or worse than 6" of lower density (50kg) one?
I'm asking cause cause I can get a good price for high density rock wool.
(If anyone is interested: Its Heralan DPF-100 (100kg/m³, 100mm) for under 18€/m².) You can find it on www.heraklith.com.

[Ethan Winer]

Originally Posted by Mr. Dreq

Ok, now I'm also getting really confused!
Well, would 6" high density (100kg) material perform better or worse than 6" of lower density (50kg) one?

The problem is none of the published standard data shows absorption below 100 Hz. The only test I know of that attempts to answer this question is my own here:

www.ethanwiner.com/density/density.html

--Ethan

[bpape]

I don't think it would be any worse, but it likely won't be any better either. It might gain you a tiny bit way down deep but is it worth double the cost? IMO no. For double the cost, I'd do 12" of the lower density. I KNOW for a fact that will perform better.

Bryan