Yo Tom,and anyone with an interest in this discussion: What about the cans of fix a flat from auto parts stores?
Air Bladder Isolation, Cheap
(As reported in Soundstage) I am very impressed with sonic improvements using 12-14" X 2" bicycle inner tube under CDP with mass loading on top. Local dept store bicycle dept has tube for $6 and hand air pump for $4. Using just enough air in tube to provide 1" height when fully loaded, and placing mass loading on top......you can buy Bright Star little rock $1-200, or buy 10-25lb metal barbell plate (can wrap in black dish cloth) or use lead shot in black sock etc. Provides deeper bass and more 3D soundstage than any cone or similar device, better than vibrapod, good for detailed SS systems, anyone else tried similar set-up, Sam