Using a mixture of Auralex and Rockwool for Bass Traps

[JustinFrench]

Anyone?

[Mad Sonicist]

I'm somewhat in the same boat as you. I've made 3 absorbers with 2 panels of 2" OC703 each. Since these are to replace some Auralex 2", I have a lot laying around. So I put a layer in between the 703 panels in one of the absorbers. I'm doing testing now w REW. I didn't do a test that specifically targets any difference, but I'll give that a go this evening and let you know. My sense though is that it didn't make much difference.

[JustinFrench]

Thanks Mad Sonicist, would be good to know if it's worth it or instead just use 6" of rockwool and just use the foam for something else

[sheggs]

Originally Posted by JustinFrench

Thanks Mad Sonicist, would be good to know if it's worth it or instead just use 6" of rockwool and just use the foam for something else

Foam and rock wool in the same panel? This is like genetic modification to many here.
I would personally use just rock wool in the panels and the foam for something else. Addiing foam to rockwool is not going to work the same as the thickness of rockwool

[JustinFrench]

thanks for the info. I just don't like the look of the foam especially as I'm going for lighter tones in the new studio, I might just sell all the foam then or possibly cover it with some fabric.

[sheggs]

Originally Posted by JustinFrench

thanks for the info. I just don't like the look of the foam especially as I'm going for lighter tones in the new studio, I might just sell all the foam then or possibly cover it with some fabric.

We did some testing on the difference between foam and rockwool, here's a newsletter we did on it back in Feb -
Testing Acoustic Foam Bass Traps

[JustinFrench]

What are your thoughts of using Hemp Insulation and what thickness would you recommend?

heres a link to a UK supplier: Hemp Insulation Rolls & Panels

[hsal]

We did some testing on the difference between foam and rockwool

One type of foam

gas flow resistivity of foam products range from around 5kPa*s/m² to 12kPa*s/m²(caruso isobond wlg 35).

I have seen another test with different results, probably due to different type of foam?

Acoustics Forum • View topic - Corner Absorption Comparision test

regarding the original qestion, need to know gas flow resistivity, an estimated guess is that it is best to make seperate traps, thick traps when using the auralex, 10 inches or more.

As for roxul/owens corning, lots of info on the forum.

[Mad Sonicist]

Though you already have quality info, never the less, here are the tests that I did. To my noobie eye it looks like there is very little difference by adding the auralex to (in my case) 4" of OC703.
behind the speakers with Auralex


without


back wall with


without


These graphs only show up to 500Hz though.

[Mad Sonicist]

Sorry for the gigantic images!

[sheggs]

No, its not really made much difference at all for the bass.
I would recommend more bass trapping with rockwool