My experience with isolation and dampening of stereo components has yielded more focused images, more detail and tighter, more detailed bass response. First, a very obvious improvement is cones under the speakers. My Thiels come with cones, as do many speakers. When roughing in the position of the speakers on initial set-up, I left the cones off. Images became focused and crisp once I put the cones back on. Very obvious change. The other big change was when I remodeled the room by replacing the carpeting with a 7/8" Hickory wood floor. The bass response was the biggest improvement. I know the additional thickness of the wood made the floor much stiffer. Room response can be a key element in good sound. I have had my stereo on a concrete slab years previous in a different house. I think a concrete floor is too stiff and deadens the music. Of course, speaker type may play into it too. And a carpeted floor can be fine too, provided the sub-flooring is stiff enough. I had one buddy who added braces to his sub floor. He had an unfinished basement so he could do that. It made a difference.
I had my turntable, CD player and Amp sitting on Granite slabs for years. Of course, these components had additional rubber dampeners on top of the granite. One day, I stuck my wife's bamboo cutting board under the CD player. The change blew me away. So under the CDP is one cone about where the motor rests, and two Sorbathene feet. And then under the bamboo board are three closed cell foam pads. Then the granite then the cabinet shelf. The cabinet feet are on spikes on my precious wood floor.
So I tried the bamboo board under the turntable. It changed the sound too. I wasn't sure that I liked the change, but when I added three closed cell foam pads between the wood and granite, then I liked the sound.
So here is the kicker. I put a bamboo cutting board under my big brute of an Amp and the improvement in sound was again astounding. So the amp sits on the bamboo board which is on a granite slab, then four isolation disks and then the wood floor. I never expected a change just by putting a wood board under the amp. One conclusion I have is, granite slabs are good for adding stabilizing mass, but components do not react well when coupled to the granite, even with rubber isolators in between.
Another experiment that did not yield good results: I tried subsitituting 70 durometer rubber strips in place of the closed cell foam pads between the wooden boards and the granite. I did this under the CDP. The highs sounded awful and even had a shrill sybillance. I left them there for a couple of weeks. I almost forgot about them and actually was starting to wonder if my CDP was going bad. Then I remembered putting the rubber pads under the wood. I pulled them out and the highs returned to normal. A remarkable difference in sound and I have no clear idea why. I would have thought those rubber pads were too far removed from the CDP to matter much.
So, experimentation is required. One type of dampener might produce good results in one system but not so good in another. I recommend not investing too much money in these materials. The brass cones and Sorbathene feet are the most that I have ever spent. The bamboo cutting boards were not too expensive. They were certainly cheaper than some special audio boards or even carbon fiber boards. Not saying those wouldn't work even better. Just trying to keep costs down.
