Quatro Wood best feet

One thing to understand is that most all Vandersteen feature cabinet within a cabinet construction WITH a proprietary constrained layer damping between cabinets, so the cabinet is not vibrating a lot.
RV is data driven and the 7 cabinet is his reference which adds an autoclave cured carbon fiber wrap to the above mentioned construction- the Treo is remarkably inert and weighs 85#, Quattro even more massively constructed!
try them out with factory spikes, shoes
try them out
get a baseline
then try other products
hard to beat the Amazon return policy

where I can get a pair 2 inch thick black granite with reasonable price in bay area? I think I should still try it as RV advised.

I steered you wrong
service via Factory, parts via your dealer
sorry about that!
jim

Guys, granite usually comes in 1.5" slabs.  Get a set of 3" and put 4 more washers on the rear spike and see how that works out.  Go to any place that sells/makes granite counter tops.  Shouldn't cost more than $300 for the pair. I went 1/2" boarder around the speaker for my size.  Measure them though as the size is a bit different than what's on the site.  

@tomic601 No problem, RV told me just give dealer a call to order. I'm still waiting for my Leica DISTO to arrive. BTW, where I should get test track?
@ctsooner Yeah, RV suggested 2inch thick but it seems 1.5" or 3" is more common, I able to find one 12x18 3" for only 76 online plus 40 shipping online, my local shop ask 180 for one 12x22 2".