Granite Slabs

Yeah, granite will not completely isolate, but may transfer less noise than a suspended wooden floor.  I’m not sure how much extra isolation you need with 200 lb speakers on the floor.  Nothing is perfect, but perhaps a minus K platform is closer than most everything else.

You want to decouple.... Townshend Podiums 

_recommended, 

As an added bonus, they add very little height to your already perfectly aligned speakers.

Just trying to figure out if I want to get my speakers off the carpet with spikes onto a platform of some sort. Not sure which is a better sound/solution.

See here and here.

Mike

Amazon sells machine plates at a reasonable cost. If you are lucky and the dimensions fit your speakers footprint, you might be able to score a pair for an acceptable price. Otherwise, going to a local marble dealer would be the next alternative.

I own Vandersteen Treo's. Mr. V. swears by adding a 3 inch granite base allows the speaker to perform optimally.  I own the Townshend speaker podiums, but added them to my components instead of the speakers, where they have clarified the bass significantly.

Bob

I bought travertine tiles from Floor & Decor.