What do you put underneath floorstanding speakers?


I have B&W cdm7nt speakers on spikes and I was wondering if there was something to put underneath the speakers to improve the sound and also possilby reduce the sound in the apartment below.
ice2000

I don't know how the IsoAcoustics Gaia footers would work in this situation but that might be something to research.  I am sure someone a lot more knowledgeable than me would be able to answer that question for you.  Just an idea. 

Interesting that nobody mentioned springs underneath their speakers.  I put 6 under my 70-something pound speakers, and the improvement was stunning, regardless of their cheap $26 per 4 of them. The bass tightened up noticeably, and the soundstage depth increased, and the imaging became better defined. I consider these a poor man’s version of Townsend isolation bars. I got mine from China, via e b a y. They are known as 4Pcs Turntable Audio Isolation Feet Pad Spring Sand HiFi Speaker Floor Protector.

They are very reasonably stable with speakers, but I will caution their use if you have kids and large animals in the house.