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
Based on what I’ve read, if the floor is cement or tile, covered with carpet or not, it’s best to couple the speakers with the hard floor using spikes, direct or through the carpet. If the floor is suspended and is covered with hardwood, e.g., basement underneath, second floor, etc., it’s best to decouple using a semi hard material, e.g., sorbathane, etc. I can only attest to the second scenario and am using Herbies brass gliders with a layer of their Fat Dots together under the speaker spike. Happy with the results. YMMV.
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.