cones or amp stand-???

Since the entire house/apartment structure is moving due to the sesimic vibrtation, rigid structures will only ensure the component vibrates along with the seismic motion. That is the point of Shannon Dickinson's article! -- that something besides rigid structures is required to isolate the component from the very low freq. vibration (0-10 Hz) caused by traffic, Earth's crust motion, etc. Recall this article was published soon after advent of Vibraplane, perhaps the first highly effective isolation device, one that set audio on its ear (as it were) as isolation was quite a new concept back then.

Geoff Kait,
machinadynamica.com
Machina Dynamica, maker of Nimbus Sub Hertz Platform

Respectfully disagree that airborne vibrations are the chief culprit in most audio systems. In fact, I would go so far as to say that airborne vibrations are significantly less critical than seismic vibrations. So we disagree substantially on this point.

Machina Dynamica isolation stands actually address vibrations higher up the frequency scale (as well as the very low seismic type) produced by airborne or motor noise, etc. by utilizing "selective frequency damping" techniques (for both Nimbus Sub-Hertz Platform and Promethean Base.) So I won't say airborne vibration is a non-issue, only a "secondary" one.

Geoff Kait, Machina Dynamica

Geoff Kait, Machina Dynamica

Exactly! Same goes here.