Vibration absorbing material.

Looking for a way to isolate vibrations in my wood enclosed stereo cabinet. I've already had custom acrylic shelves made to replace the glass ones, put adjustable spikes on the bottom to penetrate the carpeting, and put some of that dynamat (vibrations absorbing material used in car audio) in areas that cannot be seen like underneath, behind and on top of the cabinet. Still have room underneath and on top of the cabinet to add something else that would absorb vibs, any ideas?
Troy