SDR (audio)

XDR (eXtended Dynamic Range, also known as SDR (Super Dynamic Range)) is a quality-control and duplication process for the mass-production of pre-recorded audio cassettes. It is a process designed to provide higher quality audio on pre-recorded cassettes by checking the sound quality at all stages of the tape duplication process. In this way, the dynamic range of audio recorded on an XDR-duplicated cassette can be up to 13 decibels greater.[1]


History

XDR was originally developed by Capitol Records-EMI of Canada in 1982 as "SDR" (Super Dynamic Range). Capitol in the USA then adopted the system for its cassette releases that same year, renaming it "XDR".[2]

Process

The XDR/SDR process involves many steps, the most prominent being:

  • Duplication of the cassettes from a 1" wide master loop tape mounted in a loop bin duplicator (as opposed to standard cassette duplication using a 1/2" master loop tape), resulting in clearer high frequencies, greater bass response, and less noise.[3]
  • Recording a short test toneburst at the beginning and end of the program material on the cassette, to detect for any loss of audio frequencies in the audio spectrum. The toneburst consists of 11 tones about 0.127 seconds in length (with 0.023 seconds of silence in-between each tone), from 32 to 18,000 Hz. These tones are recorded on the cassette, and are read during the duplication process to detect if there is any loss of any audio information.[4]

As well as with EMI & Capitol Records, PolyGram and other labels also offered cassette releases duplicated with the XDR process.

References


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.