Decoupling Your Speakers for Improved Clarity
Decoupling your speakers means isolating them from whatever surface they are sitting on. This reduces or even eliminates vibration travelling through the surface which can otherwise cause comb filtering.
Sound travelling through the surface can reach your ears before the direct sound from the speakers. This causes dips and peaks in the frequency response at lower frequencies.
There are a number of ways to decouple your speakers, some more effective than others and some cheaper than others. Foam pads, Sorbothane (a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper), dedicated stands such as the Isoacoustics ISO range and Isoacoustics ISO Pucks, and stands that have spikes which make minimum contact with the floor can all make a big difference to the clarity you hear in the low end.