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Sound formats

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A 35mm print with both variable area and variable density mono tracks.
Example of a 35mm print with SDDS, Dolby digital, optical SR, and DTS.

Sound formats are technologies that allow recorded sound to be synchronized to (or otherwise accompany) a film. Sound formats also encompass more advanced technologies like noise reduction and sound processing. Before the advent of sound formats, all films were silent.

  • magnetic sound, optical soundtrack, digital sound/sound on disc
  • magenta vs. cyan vs. black/silver/gray for optical tracks
  • Determining sound formats (esp. optical formats)
  • Determining sound levels - best practices
  • Amplifiers?
  • Sound processors
  • Speakers


Sound format Type 70mm? 35mm? 16mm? 8mm? Super8? Other gauges? Notes
Mono Optical x x variable density vs. variable area
Stereo Optical x
Dolby SR (35mm) Optical x
Dolby A (35mm) Optical x
Dolby Digital Digital x Also called Dolby SR-D
DTS Digital x x x
SDDS Digital x
Dolby SR (70mm) Magnetic x
Dolby A (70mm) Magnetic x
Magnetic Magnetic x x x x x