I used OC705 for my rear wall corner broadband superchunk bass traps (34" x 24" x 24"), itchy stuff as everyone here knows.
Someone on AVS suggested this stuff.
http://www.acoustimac.com/index.php/diy-acoustic-materials/acoustic-insulation-material/ecoinsul422.htmlI got some, and comparing its specs to OC705 seemed better at low freq 100 - 125hz and jusr slightly lower @ 250hz (0.63 vs OC705 @ 0.71).
From the acoustimac website info:
Sound Absorption Coefficients (1/3 Octave Band Center Frequencies. HZ)
Hz
100 125 250 500 1000 2000 4000
2" Thickness 0.38 .39 .63 1.18 1.11 1.06 1.09
An even greener alternative to cotton insulation:
Cotton insulation works as well as its fiberglass counterparts, however this material can be prone to mold and is not as biodegradable and recyclable as cellulose which is made from recycled newspapers and cardboard products.
Better Performance than Fiberglass!
Oh yes, it’s true! This cellulose based insulation has even higher absorption coefficients than our standard insulation material, so not only is it more eco-friendly, it also outperforms its fiberglass and mineral wool counterparts hands down.
Freq 125 HZ 250 HZ 500 HZ 1000 HZ 2000 HZ 4000 HZ NRC
OC-703 (2") 0.17 0.86 1.14 1.07 1.02 0.98 1.00
Freq 125 HZ 250 HZ 500 HZ 1000 HZ 2000 HZ 4000 HZ NRC
OC-705 0.16 0.71 1.02 1.01 0.99 0.99 0.95
Therefore, I used it to make upper corner broadband bass traps and my front wall corner broadband bass traps.
Rear wall upper trap

Putting on the Kraft paper to block mid-hi frequencies:

1st one wrapped and done!
Those drywall edges made all the difference, I'm going to add those as lesson learned to lower bass trap post. Much crisper look.


Installing into the HT room.
I used a 30+ year old hydraulic bottle jack as 3rd hand...

Front wall (not covered in this pict....got it done just before this HT meet held 5/14/2011)
