Digital Coax Audio Cable Vs. Fiber Optic Audio Cable

Digital audio connections, used in home theater applications to connect a DVD player or HD cable or satellite box to surround sound receiver, can be one of three types: AES/EBU, S/PDIF or TOSLINK. AES/EBU is used only in pro audio applications. Consumer electronics use either S/PDIF (commonly called coaxial), or TOSLINK (commonly called optical).

S/PDIF

S/PDIF stands for Sony-Philips Digital Interface. A S/PDIF connection uses a single audio cable and has standard RCA type plugs on either end.

TOSLINK

TOSLINK stands for Toshiba Link and is an optical connection that uses fiber optics to connect digital components. Toshiba originally developed it to connect its CD players to its receivers.

Length

One primary difference between S/PDIF and TOSLINK is in length. A TOSLINK connection's maximum practical length is five meters, with a theoretical maximum length of 10 meters. A S/PDIF can go 10 meters in practical applications, with a theoretical length of 20 meters being possible.

Connections

The connectors on a S/PDIF cable are much more secure than those on a TOSLINK cable and much less prone to falling out when jostled.

Bandwidth

S/PDIF has a higher bandwidth than TOSLINK and can handle sample rates up to 192 kHz, while TOSLINK maxes out at 96 kHz. This reduced bandwidth can also result in greater jitter (variation in the transmitted signal) in a TOSLINK connection.

References

• TOSLINK vs. S/PDIF