Which Roxul for Bass Traps??

Hello, I have been turned on to Roxul fiberglass products as a cheaper alternative to OC703/705. Which Roxul product should I use for corner bass traps? Can I use the same product for wall panels? Thanks, Caz www.pascalgoespop.com

Cheak the prices in your area to make certain it is cheaper. Any of the 2.5 to 4.0 pcf material will work well in both uses. The best bang for the buck inmy part of the world (hint about your loaction in your profile) is Roxul "Safe n Sound." Andre

AVare wrote:

Cheak the prices in your area to make certain it is cheaper. Any of the 2.5 to 4.0 pcf material will work well in both uses. The best bang for the buck inmy part of the world (hint about your loaction in your profile) is Roxul "Safe n Sound." Andre

Is that Safe n Sound rigid? Thx, Caz

casimer: As far as I know, Roxul makes most of its insulation from Rockwool (not fiberglass). You can find links to several of their products from here http://www.bobgolds.com/AbsorptionCoefficients.htm Safe n Sound is described here: http://www.roxul.com/sw18172.asp I've held it in my hands, and it's not as rigid as their RHF 80, but it's stiffer than fluffy fiberglass pink R31. Safe n Sound has a denisty of 2.5 pcf (40 kg/m3).

From Roxul's website: RHT™40Architectural/OEM (3.5-4lbs. pcf) Acoustical Performance: ASTM C 423 CO-EFFICIENTS AT FREQUENCIES (3”) 125 250 500 1000 2000 4000 NRC 0.62 1.03 1.20 1.10 1.08 1.10 1.10 _____________________________________________________ SAFE AND SOUND (3”) Acoustical Performance: ASTM C 423 CO-EFFICIENTS AT FREQUENCIES 125 250 500 1000 2000 4000 NRC 0.52 0.96 1.18 1.07 1.05 1.05 1.05 The RHT40 specs. look better for low freq's. (Way better at 4") TOM

Tom, all those absorption specs are done in a free field; the material is placed on the floor in a test room, usually in an 8' x 9' sample, and absorption tests run; if the edges of the sample are not "screened" (covered) then the absorption values can exceed "1.00", which is theoretically perfect. When used inside a wall, there are different dynamics at work; for inside walls, the safe and sound at 2.5 pcf should give more even TL results across the frequency range, because reportedly the heavier weights improve mid range TL at the slight expense of low frequency TL; and since LF is the hard stuff to stop, I generally recommend designing a wall for the lows and letting the rest fend for themselves; especially in these days of runaway subwoofers... Steve

:shock: Zzzzzinggggg...Right over my head. :oops: :?: Sorry, I know this is about bass traps, but do you mean the lighter 3" (2.5pcf) has better TL loss in WALLS than the 4" (3.5pcf) for low freq's? :? :? :? Are you taking about the overall NRC rating? If not, I am completely confused now. (I may have misread this and got disoriented.) Must....drink....beer.............

puppypuree wrote:

:shock: Zzzzzinggggg...Right over my head. :oops: :?: Sorry, I know this is about bass traps, but do you mean the lighter 3" (2.5pcf) has better TL loss in WALLS than the 4" (3.5pcf) for low freq's? :? :? :? Are you taking about the overall NRC rating? If not, I am completely confused now. (I may have misread this and got disoriented.) Must....drink....beer.............

Ypu can use either material for bass traps. There you go, straightforward. Check which is cheaper in your part of the woods. :)

Andre answered re bass traps - for within a wall, a complete fill with insulation lightly touching both sides is best - so the thicker would win by a small amount. The heavier PCF you mentioned isn't drastic enough to hurt as much as an incomplete fill would - ideally, a complete fill with 2.5 PCF stuff should work best for any given wall thickness - another good way is the 2.5 to 4 PCF within stud cavities in a double framed wall, with unfaced standard fluffy batts between the frames. This gives complete fill, good damping of wall panels, code acceptable fire blocking for most areas, and enough "give" to keep coupling between leaves to a reasonable amount... Steve