A Copernican View of the Turntable System

Halcro,
I know my statement and Jonathan's are not the same - no 'quite' about it. My 'if I implement pods' comment involves a pod, his doesn't. I agree with Jcarr's recent comments and am on record moons ago on these fora having said something similar. But if a pod is to be used, having everything extremely well-coupled (de-coupling I assume is isolation, which should be avoided) and rigid will approach JC's suggested goal. Some pod implementations have different isolation systems under the pod and the table, which makes for a different arm-bearing-to-table-bearing interaction, and this is something I would suggest against. In the end, it all comes down to implementation (Dgob's Chinese cats and your arm pods).

'Well away' is perhaps different than what you would call 'well away' given the concept of 'distance' in a Japanese living space is probably different, but it is still out of the direct radiation pattern of my speakers. My P3 is on a large wood rack, but it does not matter much. The P3 has construction, shown here much like Jonathan's suggested method, with an isolation platform built-in. The fact that results differ slightly with the top down suggests air-borne effects, but I have no doubts my room could be improved.

Downunder,
The lid of the P3 is specifically designed to combat airborne vibration which might affect playback.

The fact that results differ slightly with the top down suggests air-borne effects,

Not necessarily. If the structure-borne feedback is resonating through the metal base of the P3 (and those 'isolating' springs can often be a happy conductor of resonating frequencies) and into the motor and/or platter, closing the lid can often form a 'capture chamber' being filled with the release of the feedback into air-borne frequencies.
Sprung decks like the Linn Sondek can surprisingly be the most prone to structure-borne feedback.
Looking at your 'System' page, I suspect your floor-mounted rack is the limiting factor. Mark Doehmann of Continuum stated that it took $30,000 of engineering to provide a floor-mounted stand like his Castellon with the same isolation as a wall-mounted shelf.
Suspended wood floors such as yours, are extremely difficult to isolate from structure-borne feedback.....and in Japan, with the seismic activity constantly providing Dertonearm's micro movements.....it should be avoided at all costs.
Any chance of you trying for a wall mount........just to experiment :^)

Halcro,
I don't have suspended wood floors. They are poured concrete with a thin fake wooden flooring cover. The rack in the system page is old. I haven't added pics in a couple of years.

The P3's springs are actually surrounded in an oil solution inside the rubber casing. The resonant frequency of the isolation system is set to be 3-4Hz. The effect is quite different to that of a normal suspended table like a Linn or Thorens. Other P3 owners might attest as to the isolation system's effectiveness.

I don't doubt that if one tried hard enough one might be able to create a 'capture system' as you propose. But the happy effect of mine is that closing the lid while playing often has a salutary effect, and never deleterious.

In Japan, TTs rigidly coupled to wall mounted shelves would be just as affected as rigid floors, like mine, with earthquakes. However, earthquakes/tremors are not the only thing causing building structural resonance, especially in cities. And not just in Japan.

T_bone,
Is your concrete floor 'suspended' or cast on the ground?
A suspended slab can often pose problems due to dynamic movement and deflections.
It's true that seismic movement is hard to protect against but most other external influences (even in big cities) can be minimized especially by wall-mounting.
The de-coupling effect of metal brackets combined with wood-based shelving cantilevered off masonry walls works in all but the most complex of situations.
SOUND

Suspended. I don't worry about whether my floor will flex though. I know it will. Earthquakes affect the sound because the building shakes (for those not used to them, earthquakes can be 'noisy'). Having had a setup on the ground floor (concrete slab) before, I know it will move too. That's life in the big city...