As to weight of the speakers - they are 90 lbs each. The vibration is not bad - the speaker cabinet does not noticably vibrate. But, at 105 db peaks with my feet on the carpeted wooden floor, sitting 6 feet away, I can feel the base. It seems to me that completely eliminating any transmission along the floor would be ideal. I cannot imagine that this would not occur in even the heaviest of speakers without decoupling. The garage rubber pads sound like just the ticket - I'll check out home depot - the hocky pucks are also an interesting idea.
Speaker shock absorbers
From time to time people have posted different methods for mechanically decoupling their speakers from the floor to reduce vibration. Some of these have involved using a ply system of rubber strips and wood strips, which seems reasonable to me. I have looked for suitable sized sections of rubber or even for large sheets to cut up but have been unsuccessful. To those who have used that method -where did you find the material and what thickness of rubber and wood did you use for each layer - finally how many layers did you end up using?