How to isolate turntable from footstep shake or vibration


Even while the Oracle turnable that I use has a built-in springs suspension by design there is a low or even sub-low frequency boom every time someone walks in a room. This becomes really bad with the subwoofer’s volume set high as the low frequency footsteps make straight to subwoofer where they are amplified shaking everything around. It seems the cartridge is picking up the footsteps very efficiently as even a lightest foot down becomes audioable. What can be done to attempt to isolate the turntable from the low frequency vibrations? Interesting, that the lower the volume of the subwoofer, the less the footstep shake is evident and with the subwoofer turned off it is a barely a problem at all. 
esputnix
Haha on me. Thank you, thecarpathian, for correcting me. I was indeed thinking of the Tacoma bridge, not the Verrazano. Only today did I see my error. Anyway, the point of my analogy still stands, or falls.

If the Verrazano were to shake itself to death, THAT would be spectacular.
Great bargain in Audio-Silent Running Audio (SRA) VR platform.
Think they are new $1500 built for your TT.
When I installed mine, all of a sudden, my Garrard 301 was able to preform as designed. A $10K TT turned into a $20K+ TT.
No exaggeration. I was floored and bought another for my preamp.
Go buy Solid-Tech Feet of Silence.  Solved the same problem. The turntable is actually suspended in air.  I also used a 3/4 in thick cutting board to rest TT on and then placed the feet of silence at the 4 corners of the cutting board for stability.  Ingenious design
mglik, the advantages of isolating a turntable are rather obvious but a preamp? If electronics were sensitive to vibration F22's would be crashing all over the place. For those of you who do not know what an F22 is it is a fighter jet that can not fly without computer control. The pilot tells the computer what he wants to do and the computer does it for him. The control inputs are to complicated for a human. There is no manual option.
Get a piece of 2x4 and place it between the back 
of the rack where your turntable sitting (center)
 and the wall .That should take care of footfalls.