Number of opinions of this = number of audiophiles present + 2. [ some are bound to be of at least two minds on the subject, as I am]. I use and sell the Star Sound brass cones, which work well; I have also used the FIM roller bearings which I also sell. I really like the SR MIGs also, haven't used them under speakers yet as the ones I have set up have their own outrigger base. There was a really good looking outrigger base with spikes for a not totally unreasonable price but the web site has disappeared and I fear they are gone. Maple or sandwiched MDF shelves should work; years ago I knew someone who was using grave markers, he called them "dead weights". With the exception of the roller bearings I like the coupling devices better than isolating ones; haven't tried all obviously; Ceraballs works well under components but haven't had them under speakers.
