On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density,
low density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Andy