Herbie's Audio Lab recently ran an overstock sale on the Black Hole CD Mat and I decided to try some (200). These are generally applied permanently to each disc. It is comprised of a polymer intended to absorb vibrations within the rapidly spinning disc and yield improved sound quality. If smoother treble, more harmonically developed more present midrange and maybe the greatest improvement of all, richer more "plucky" bass are sound qualities you value, you might want to go to Herbie's site and pick some up and give them a try. Steve Herbelin stands behind everything he sells so you have little risk in giving them a whirl. The more mats you buy the less expensive is each mat.
