Dolby Spectral Recording, commonly called Dolby SR, is a four channel sound format – left, center, right and surround. It is the most common optical sound format on films made after 1986.
Dolby SR vs. Dolby A
Dolby SR is difficult to distinguish from Dolby A by sight. Here are some tips on telling them apart:
- Some (but not all) films made after 1986 will have Dolby SR tracks, though A-type was still in use well into the 90s.
- Some (but not all) films with Dolby SR tracks will display the words "Dolby SR" with the Dolby logo in the end credits. Some (but not all) films with Dolby A tracks will display the word "Dolby" - or "Dolby Stereo" rather than "Dolby SR" - with the Dolby logo in the end credits. But be careful, just because you see one of these in the credits of the film does not guarantee that it is A Type or SR. Some films were released as both mono and stereo prints, or a film may have been re-mastered and released as SR but was originally mono. Seeing the logo in the credits is just another clue to be used with alongside other sources of information.
- Some (but not all) films with Dolby SR tracks will display the words "Dolby SR" on the edges of the film leader.
- A Dolby SR track played in Dolby A will usually sound fine, but will have more noise than you would expect from a soundtrack with Dolby Noise Reduction.
External Links
- Wikipedia: Dolby SR