I have been confused on this issue until today. Some say digital coax some say opitcal for sound. Eddie has stated that you must have an opital cable for best audio. I have been told that the digital coax and opitcal cables both do the same task and not one is better than the other...signal is just transmitted differently..I got two opinions on this. One was by tech support at Best Buy the other from a tech at Crutchfeild both said exactly the same thing not one is better than the other.. To coax vs. optical...The ONLY way the optical cable could be a better source is if you have to run 25 feet or more from one source to the other. Then the optical light would in essence transmit quicker. I doubt any of us would even notice the difference especially if your receiver has auto or manual "lip-sync" capabilites while watching a movie...music only; no difference at all. Please give me your opinions on this subject and what you ahve experienced. Thank you