SPDIF – Digital audio transmission: All in one
The short-term SPDIF, also S/PDIF, stands for “Sony/ Philips Digital Interface”. Behind this serial interface are the companies Sony and Philips who created SPDIF as a specification for transferring digital stereo and audio signals. Special about this is that SPDIF is able to transfer either optically or also electrically. The port is mainly used for CD players, between DVD players and in home cinemas, because harness can be avoided by using SPDIF.
Plug connections for SPDIF
Just like every other interface, SPDIF has special connectors, too. Within these it is differed between electrical plugs and plugs for optical transmission. For the latter the TOSLINK plug is used. The electrical transmission counts on an RCA plug with coaxial cable, very rarely also a 3.5 mm phone connector.
HDMI or SPDIF – How to transfer audio
HDMI as well as SPDIF are digitally transferring data, where HDMI is only electrical, SPDIF can even be constructed optically. In contrast to HDMI SPDIF is much older and therefore has one main disadvantage: At the beginning SPDIF was only built for PCM, by now the enormous bandwidths, for instance with DTS, are too big to be transmitted with SPDIF. A downmix of the data would be possible but would bring significant loss of performance. This is not the case by using HDMI. Another advantage of HDMI is that one cable can be saved because it transfers video and audio data at the same time.