Erik,
To tell you the truth, no sonic improvements were heard by either me or my wife (who got me these for Christmas a few years ago...). I put them under the speaker cables which are are Nordost SPM, and these elevators have been reportedly able to improve their sound but... not.
Perhaps because my carpet is 100% plush wool (most carpets are or have acrylic)? Perhaps because these cables are kind of stiff and thin and wide that they do not really settle nicely in the channels in the top of the elevators (i.e. rounder speakers cables may work better)?
But, yeah, still use them as a 'precaution', just in case static starts building up after small micro-vibrations cause the cable to rub back and forth against the carpet.
