Quatro Wood best feet

the speaker should be placed flat down onto the Svelte? what coupler I should use underneath?  Precision Couplers?

I maybe wrong

I actually did that, and RV suggested 2inch black granite with stock spike other than isolation feet. But I have stone tile floor, and concrete underneath so I though I may just need a pair good feet.

@tVandersteen stock spike shoes? I will need some.

I did mentioned Iso-Acoustics Gaia to RV, and RV suggested put a 2 inch thick black granite on the floor and set the Quatro with its stock spikes on top will give much greater time improvement........may just stay with stock feet during speaker set up process.

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.

@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!

@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".  

@tomic601 there is Realistic Radio Shack Analog in good condition listed, is it same as RS  RS Analog?
https://www.ebay.com/itm/Realistic-Radio-Shack-Sound-Level-Meter-w-case-Cat-No-33-2050-Vintage/16342...

@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.

@ctsooner Wondering where did you order your 3". my local granite shop asking price is way too high, so far lowest price I able to find online for 3" granite is here: 
https://www.grizzly.com/products/Grizzly-18-x-24-x-3-Granite-Surface-Plate-No-Ledge/G9654
but the shipping cost to my door will be even higher than the granite price:(

@tomic601 got 1  RS Analog on eBay, can't waiting for the shipment.