If you tried enough power cords, then you will know this is exactly what they are doing. Hence no single power cord (and no single cable) is best for everyone, they all act like tone control.
You often read in reviews people said:"This cord (or cable) is so good that it just let more music flow...."

Now, that to me, is a utterly meaningless statement.
Funny how a cord can affect the tonality of the music.