I built the risch panels and you can just use 6.25" faced fiberglass sandwiched between the 1/4" 100% polyester batting and it'll still work great, and its simpler. Just an idea.
Rock Wool or Owen Corning 700 Series
I want to make some wall absorbtion panels following Jon Risch's instructions, but I can't find Rock Wool or Owen Corning 700 series panels to go on the back of fiberglass. I searched for the Owen Corning website but there is not much information on the panels. Is there anybody who knows where I can get these panels or different panels with the same density? Thanks.