Two Connections are widely used for connecting Digital Audio, SPDIF (S/PDIF) and Optical Toslink1) Coaxial RCA: Cable and connectors are 75 ohm impedance and used to connect DVD players, Compact Disk (CD) and some DAT recorders to multichannel surround sound (Dolby Digital, DTS, etc) equipment.2) Toslink is a fiber optic version of the coaxial digital audio connection and is used in the same applications as coax. Most newer equipment has a Toslink optical connection. Both Types Support 5.1, 7.1 Digital Audio Surround sound Audio Formats: Dolby Digital, DTS, Cable, Satellite, Playstation3, Xbox 360Coax Digital Audio Cables:Nothing is more important than maintaining proper 75 ohm characteristic impedance in a digital audio cable. Sure, at longer lengths, you need heavier gauges for lower loss, but maintaining consistency throughout the length of cable and mating with the larger connectors capable of as close to the optimal 75 ohm characteristic impedance is all important. Belden is generally the Industry Standard for consistent quality throughout cable lengths due to quality control and overlooked attributes like manufacturing machine maintenance. All of our suggested cables for Coax S/PDIF Digital Audio are 75 ohm and chosen for their ability to transmit digital audio as accurately as possible without reflections and jitter. RCA connector cables are for Consumer Equipment, BNC connectors are for Professional Equipment.