@kalali
I agree with you. Note, however, the foam factory publishes a fair amount of specifications regarding their foams NRC absorption ratings. In fact they provide independent third party lab results too. So while what you are saying is true that they don't do much, they do *something* in the way of absorption. In my case I wasn't looking for much absorption, just something to take the "edge off" sound directly hitting dry wall. http://halr.x10.mx/AV.jpg
Also, according to what I was told by a GIK Acoustics rep, one needs 2.5 inches of foam for every 1 inch of their fiberboard. I went with 2 inches foam.
I agree with you. Note, however, the foam factory publishes a fair amount of specifications regarding their foams NRC absorption ratings. In fact they provide independent third party lab results too. So while what you are saying is true that they don't do much, they do *something* in the way of absorption. In my case I wasn't looking for much absorption, just something to take the "edge off" sound directly hitting dry wall. http://halr.x10.mx/AV.jpg
Also, according to what I was told by a GIK Acoustics rep, one needs 2.5 inches of foam for every 1 inch of their fiberboard. I went with 2 inches foam.