Experience Loading Speakers w/ sand or shot

In my Vienna Mozarts, I used #9 shot that I got in 25-Lb bags from a sporting goods store. It is coated with bismuth (or something) so it's a little safer to handle, but use gloves and/or wash hands afterwards - and you only do it once.

"It is also well known that sandy or unconsolidated top soil can turn to liquid during earthquakes (low frequency vibrations)." These materials do NOT turn into a liquid in terms of their physical state - they BEHAVE like a liquid with respect to their motions. Big difference!