Quatro Wood best feet


What is best isolation fee for Quatro Wood speaker other than stock spike, maybe not granite either since I have stone tile, and concrete underneath. any advise will be appreciated!

Best Regards
Zee 
zensview
@tomic601 I  I did matched impedance for M5 high pass output, and my tube amp input, I do have a Meterk Digital Sound Level Meter, should I better stay with Radio Shack Analog SPL meter for Quatro wood setup? I have to look for one!
Zee
yes you need the RS Analog , the Vandertones are calibrated to that
it should be $30-$40 on ebay

@tomic601 Sure will grab it, Thanks!
@ctsooner RV just replied that both 1.5 or 3.0 granite is OK as long as compensate for the tilt, time and phase aligned. Guess you can stay with what you have, that will also make me easier to find a pair now. 2 inch is just rare to find.