Coaxial and optical cables are used to make a digital audio connection between a CD or DVD player and a receiver. Both types transfer a digital signal from one component to the other. So, what is the difference between the two types and which is better? The answer depends on whom you ask, but in general the performance differences are negligible. Here are some facts about coaxial and optical digital cable connections.
Coaxial Digital Audio Cables
A coaxial (or coax) cable is hard-wired using shielded copper wire and is generally the most rugged. Each end of a coaxial cable uses familiar RCA jacks, which are reliable and stay firmly connected. However, coaxial cables may be susceptible to RFI (radio frequency interference) or EMI (electro-magnetic interference) and if there are any existing 'hum' problems with the system (eg, a ground loop) a coaxial cable may transfer the noise between components. Coaxial cables also lose signal over very long distances, but for home use that's usually not a problem.
Optical Digital Audio Cables
An optical cable (also known as Toslink) transfers an audio signal using a red light beam through plastic fiber optic cable. The signal that travels through the cable must be converted from an electrical to an optical signal in the CD player, then back to an electrical signal in the receiver. Optical cables are not susceptible to RFI or EMI noise because it is light, not electricity that is traveling through the cable. Optical cables are more fragile than a coax cable and cannot be bent too tightly or pinched. The ends of an optical cable use an odd-shaped connector that must be inserted correctly and is not as tightly connected as a coaxial cable with RCA jacks.
Your decision about which cable to use may be based on the type of connectors on the components because not all audio components have both optical and coaxial. I prefer coaxial cables to optical because of sound quality, although the differences are very subtle and are probably noticeable mostly in high-end systems. In general, either type provides good sound quality.
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