Density vs Depth (corner bass traps)

[andrewm2002]

I just completed a basement room for my younger brother's studio / jam room. The room is 13x17 feet and the acoustics are horrible. I want to build corner bass traps for all four corners (full height of wall)

My question is referencing information found on http://www.bobgolds.com/AbsorptionCoefficients.htm

If I am reading this correctly I can build 16" wide corner traps with the paper backing Toward the room to effectively kill the bass but not diminish all the higher frequencies. I would like to not kill all the highs because I also will be hanging 4 ~ 8 acoustical panels on the walls opposite and behind the loudest gear. However, looking over the 700 series insulation (which I can't find or afford) it seems that paper faced out r-19 will absorb very low frequencies but it will not absorb large amounts of them due to the density of only 0.5 pcf. Is that correct?

If I used paper out R-19 (6.25 inches) backed with un-faced R-30 (9.25 inches) I would have a total thickness of 15 1/2 inches at roughly 0.5 psf. If I sandwiched that down to 3.5 inches, roughly the size of the 1x4's I'm using, it would have a density of 2 psf. Would that increased Density help with the amount of sound waves that are absorbed? Would increasing the density of the fiberglass AND putting the paper towards the room make the bass trap too dense?

I'm really racking my head on the thickness vs density thing! There are so many smart people on the forum... and I know everyone is going to start advising OC 703 and 705. I can get R-19 for free and unfaced R-30 is very reasonably priced. I'm already went over budget building the room! This sandwiched design would allow roughly 1 foot of air space behind the traps.. I know that affects it somehow.. but I'm not sure how.

Thank you for the scientific advice.

Cheers

Andrew

[Glenn Kuras]

Here is the best way to say it. If the corner trap is filled you can use the low density stuff. If you make panels 4" to 6" then go with the 703,705 or mineral wool 4 pound or higher.

Glenn

[andrewm2002]

Originally Posted by Glenn Kuras

Here is the best way to say it. If the corner trap is filled you can use the low density stuff. If you make panels 4" to 6" then go with the 703,705 or mineral wool 4 pound or higher.

Glenn

I know you are a well respected and contributing member to this forum. However, I specifically said I do not have the budget to buy 703. Would 15 inches compressed to 3.5 inches work as well or close to as well as 703? That would have a density of 2 pounds.

[Glenn Kuras]

Originally Posted by andrewm2002

I know you are a well respected and contributing member to this forum. However, I specifically said I do not have the budget to buy 703. Would 15 inches compressed to 3.5 inches work as well or close to as well as 703? That would have a density of 2 pounds.

Yes you could do it that way. Dude no worries on the respect stuff. Honestly I read right over you compressing it.