When doing laser holography the standard practice is to build a large, heavy bed, like a sturdy wooden frame filled with dry sand, and lay that on top of someth

When doing laser holography the standard practice is to build a large, heavy bed, like a sturdy wooden frame filled with dry sand, and lay that on top of something that absorbs vibrations like a series of tires and inner tubes. That usually does a good job of sponging up any low-frequency vibrations so long as you don't have any harmonic issues. If you were battling a persistent hum you'd have to engineer the floors in your house to be floating in this fashion, if not the entire house.