Before buying trying either Black Hole CD Mat or full scale tuning mat I introduce above, out of curiority I decide to give a DIY mat a try. I took a unused mouse pad and cut the dual concentric shape out of the pad to my best ability based on the dimenions of the Black Hole. The mouse pad is even thicker (1.5mm vs 0.68mm) so I presume it will work better than the Black Hole because of the extra weight. I make sure the inner circle is cut precisly such that it will fit nicely into my CD / SACD player spindle.
I could tell you, at least to my ear, it makes no difference in terms of SQ, clarity, etc. I was sort of disappointed... Well, folks, don't be. I could also tell you a way that could possibly improve the clarity of CD playback and cost you nothing is to play the CD directly into the power amplifier. (make sure the impedance matched between the CD/DVD/SACD player and the PA)