Floor standing speaker isolation advice needed.


I have an older pair of KEF Reference Model Twos that currently sit on their brass(?) feet on the floor. The floor is tile but not solid cement underneath. I bought two .5" thick granite tiles for underneath the speakers and am wondering if I need to do anything else like put the spikes on the brass feet, add sorbothane under the granite tiles and/or under the brass feet or something else I should be considering? Things sound good on the top end but seem a bit subdued/muddy in the bass region. The KEFs are being driven by a Parasound Halo A23 and I’ve got a HSU VTF-3 MK 2 helping out the bass, mostly for movie duty.


Thanks for any advice.
asahitoro
I appreciate the input kalali,

Also, I can put sand in the plinths of my speakers. Overkill or not with the granite tile/sorbothane underneath and possible spikes under KEFs feet?
Thanks ricred,

I'm really not looking to drop that much coin this setup. Trying to do this with $100ish and under stuff I already have or can easily get. If I step out over the sorbothane/granite, it will probably be for something from Herbies.
Stiff Springs under a wide footprint board supporting the speakers should do the trick. It’s two, two mints in one! Isolates the speakers and isolates everything else from the speakers. 👯‍♀️ Mass-on-spring. Accept no substitutes.
Within the budget you mention, I think you should consider @geoffkait's suggestion.  He does understand the mechanics of springs. I am personally familiar with the Townshend speaker podiums which perhaps are above your budget.  The Townshends are superb at the kind of isolation Geoff is talking about.  But I expect Geoff's solution will get you much of the way to the Townshends' level. Springs in my experience are better than other devices for isolation.  I have a bunch of springs (Geoff's actually) under my other components though not my speakers.