Etran, I do use a bit of Auralex 2" studiofoam, the basic grey 2' x 4' "ruffled" sheets. It does what foam does--absorbs high frequencies. Please note that foam is NOT effective in controlling low frequencies; it does damp uppermidrange and high frrequencies. In other words, if glare, hf harshness and various high level echoes causing an overly-live sound are your problem, then abosrption might be for you.
Also please note that in my experience, Auralex LENRDs do not work as advertised. As noted above, I do not find Auralex products effective for low frequency absorption. For this you will want proper bass traps; the size and style depend on your particular needs.