Good to know: What is SPDIF?

23.10.2018

In today’s knowledge article, we want to explain to you what the SPDIF connection is all about. Even though this interface is mainly at home in consumer electronics, a few of our mini PCs are equipped with this digital audio connection. In this article, you can find out exactly what SPDIF is, what the connection is intended for and how it compares to HDMI.

SPDIF - Digital audio transmission: All in one

The abbreviation SPDIF, often also S/PDIF, stands for "Sony/ Philips Digital Interface". Behind the serial interface are the companies Sony and Philips, who created the SPDIF specification for the transmission of digital stereo or audio signals. The special feature is that SPDIF can transmit both optically and electrically. The interface is mainly used with CD players, between DVD players and in the home cinema sector, as the connection means that only a single cable is required and cable harnesses can be avoided.

Plug connection of the SPDIF

Like any other interface, the SPDIF also has special connectors. Here we differentiate between electrical connectors and connectors for optical signal transmission. A so-called TOSLINK connection is used for the latter. The electrical transmission relies on an RCA connection with coaxial cable, in rare cases also on a 3.5 mm jack plug.

HDMI or SPDIF - Which to use for audio transmission?

Both HDMI and SPDIF transmit data digitally, whereby HDMI works purely electronically and SPDIF can also be optical. In contrast to HDMI, SPDIF is much older and therefore has an ever-increasing disadvantage: SPDIF was initially only intended for PCM and can no longer transmit the enormous bandwidths now used by DTS, for example. Although it is possible to downmix the data, this causes a significant loss of performance, which is not the case with HDMI. Another advantage of HDMI is the simultaneous transmission of video and audio data, which eliminates the need for an additional cable.

Q: chip.de, heise.de