S/PDIF

Stands for "Sony/Philips Digital Interface" and is pronounced "spid-if"). S/PDIF is a digital audio transmission standard for transferring audio between two devices. It is uni-directional (one-way) and supports uncompressed stereo audio and compressed surround sound audio.

A S/PDIF audio signal may be transmitted over coaxial or fiber optic cable. Coax transmissions use RCA connectors, while optical transmissions use Toslink connectors. Regardless of the transfer medium, a S/PDIF signal is always digital, not analog.

Since S/PDIF supports multiple types of connections, S/PDIF ports on AVRs and other devices may not be uniform. Most modern devices that support S/PDIF provide an optical Toslink connection.

S/PDIF supports uncompressed 2-channel (stereo) audio, making it an ideal interface for CD players, turntables, and other stereo audio devices. While S/PDIF supports surround sound signals, it does not have enough bandwidth to transmit more than two channels of uncompressed digital audio. Therefore, S/PDIF must transfer 5.1 and 7.2 surround sound audio in a compressed format, such as Dolby Digital. Specifically:

S/PDIF Supports:

  • 2-channel uncompresed 16-bit, 44.1 kilohertz stereo audio
  • Compressed surround sound audio (Dolby Digital, DD+, and DTS)

S/PDIF Does Not Support:

  • More than two channels of uncompressed audio
  • Uncompressed surround sound audio (Dolby TrueHD and DTS-HD Master Audio)

Uncompressed surround sound audio requires a high-bandwidth digital connection, such as HDMI or ADAT.

Updated August 15, 2020

Definitions by TechTerms.com

The definition of S/PDIF on this page is an original TechTerms.com definition. If you would like to reference this page or cite this definition, you can use the green citation links above.

The goal of TechTerms.com is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about the S/PDIF definition or would like to suggest a new technical term, please contact us.

Want to learn more tech terms? Subscribe to the daily or weekly newsletter and get featured terms and quizzes delivered to your inbox.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe or change your frequency setting at any time using the links available in each email.

Questions? Please contact us.