My speaker cables are NOW run under the carpet, between the carpet and the cement floor.
I notice an immediate improvement in my wife's signal to noise ratio, and total harmonic distortion dropped significantly too.
Plus, the annoying 'thud' that I used to hear every time she tripped over the cables is completely gone and replaced by a warm smile and an occasional roll in the sack.
Proof positive that cable placement can dramatically affect your listening experience .