I had an extra set of AR performance series audio cables so I pulled the two wires apart and I use one for my sub and one for digital coax from my dvd player to my receiver. It sounds great to me, but am I missing out on good sound using these cables and not the AR digital coax or composite video which are said to be 75 ohms. the audio cables lack an ohms rating. the only visible difference between the cables is that the digital coax and composite video cables are thicker than my audio cables. Becuase the music and movies sound great through my audio cable used as a digital coax cable, does that mean it is in fact 75 ohms?