I wouldn't think that to be the case with DVD or CD players, I don't no of any pre-fab cables 15' long, most manufacturers advise to keep the coaxial cable run short, in fact, Audio Note recommended a .75 meter as optimum. So they either have a standard impedance which makes this a non issue or perhaps the impedance issue is off base for non-computer gear. I don't know, it's just contrary to what the consumer electronics companies say. You would think the shorter the distance the better.