Vibration Theory - Isolate or Drain?

i use only absorptive, soft materials under components.

my product of choice is a polyurethane-based sound booster.

i use 4 per component. the durometer varies with the weight of the component.

my second choice is furniture foam. my digital components are sitting on furniture foam.

emplying devices under or on top of a component, is a form of tuning, like a tone control. since no stereo system is perfect, hard or soft objects will affect the frequency response. i would conjecture that the choice to absorb or drain is subject to personal taste.

i prefer soft objects, because i find that usuually, hard materials, "harden" the sound.