Speaker isolation

Hi guys, after putting isonodes under everything except the mls,the mind has turned to the speakers.
Most are using maple or marble/granite. Etc. Must mention have a cement slab and carpet. Also spikes.
Tried a half inch marble bread board with one inch blue closed cell foam under the board.--- result ,improved treble.
Then used a piece of our hardwood-jarrah,similar to ebony in looks and density,without the board-- result, imroved mids ,but made the base a bit wooley??
So i am wondering what may work for the base??
Tried combining the three, got big improvement across the spectrum,but base is still not quite right.
This leads me to wonder are the different materials acting on certain frequencies out of the speaker?? As they must,and if so,
whats best for base??
Could go with maple ,it seems it works across the spectrum ?.or could use the isonodes or some magnetic or brass footers??
I wonder if going for multiple layers of different density and different materials including foam,balsawood, cork,brass,ally and perhaps steel??
Say, 10--20 thin layers,may be the way to go??? And aranged in decending order,and then back the other way??
So any imput will be gratefully accepted,cheers cliff.

one of the greatest upgrades is Townshend isolation systems
makes a fantastic difference to sound and improvement
I am not sure if available in Australia though

http://www.townshendaudio.com/hi-fi...e-cinema-vibration-isolation-speaker-podiums/

Stillpoint Ultra5s and Ultra6s are known to do wonders under speakers. Various adapters threads can be purchased directly from Stillpoint.

I use Stillpoints SSs under my Spires on a carpeted basement floor. The results are outstanding! Very highly recommended.