Auralex Mineral Fiber?

[Myriad_Rocker]

http://www.sweetwater.com/store/detail/MFiber2/

Is this stuff the same as OC 703? It breaks down to be about $1.87/sq ft. How does that compare?

[bpape]

Not really. That material is much denser than 703. I believe that is either 6 or 8lb/cu ft density where 703 is 3lb.

[Anomaly Design]

Its the same thing just $10 more expensive... Heres the stuff your lookin for at a good price.

http://www.atsacoustics.com/item--Ow...f-6--1004.html

[Myriad_Rocker]

Originally Posted by bpape

Not really. That material is much denser than 703. I believe that is either 6 or 8lb/cu ft density where 703 is 3lb.

So it's better? (the Auralex)

[ChuckU]

Originally Posted by Myriad_Rocker

So it's better? (the Auralex)

I second that question. I have access to some 8 lb and want to know if it will do what 703 and 705 will with respect to low freq. I noticed that the Sound Absorption Coefficients are actually lower for 705 than 703 for most frequencies.

[Anomaly Design]

Originally Posted by bpape

Not really. That material is much denser than 703. I believe that is either 6 or 8lb/cu ft density where 703 is 3lb.

Where are you getting this information? I just checked Auralex's homepage and it didn't have density.

If its heavier it should work better on lower frequencies however this improvement might not outweigh the fact that its $10 more per unit than 703.

[myfipie]

Originally Posted by ChuckU

I second that question. I have access to some 8 lb and want to know if it will do what 703 and 705 will with respect to low freq. I noticed that the Sound Absorption Coefficients are actually lower for 705 than 703 for most frequencies.

8Ib will do a better job to a point. If a panel is 4 or 6 inches thick then I would go with the 8Ib. But if you are making super chunks then (as I have been told by many pros) that 4Ib is better. My own lab testing with 4Ib came out pretty damn nice with 4Ib as super chunks (our new product not on market yet) but one of these days I want to try the 8 pound to see how it works on the new product.

Glenn

[bpape]

I have some customers who have used it so I'm familiar with what it is.

Also, contrary to one of the answers, mineral wool is not the same thing at all as 703 or 705. One is made from glass fibers, the other from mineral slag. Besides density, it is a different material, has different gas permiability ratings, and a different matrix makeup.

For instance, compare...

Roxul Mineral Wool
RXL 60 3" 6.0 pcf (96 kg/m3) 0.78 0.89 1.04 0.98 1.01 1.02

OC Fiberglass
705, plain 3" 6.0 pcf (96 kg/m3) 0.54 1.12 1.23 1.07 1.01 1.05

Same thickness, same density, same 'A' mounting tests - very different results - expecially at 125hz. Yes - results vary from lab to lab but not by almost 40% - not if the test is done properly. In addition, the mineral wool is 'springier' than the 705 which is stiffer. So, if you add a scrim face (FRK/FSK) the membrane effect will be different and at a different center frequency.

Now, throw in 3" 703
703, plain 3" 3.0 pcf (48 kg/m3) 0.53 1.19 1.21 1.08 1.01 1.04

As you can see, 703 and 705 are much closer to the same thing than 703 and the mineral wool are.

All have their place - just a matter of what the room needs

Bryan