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:
- Most (but not all) films made after 1986 will have Dolby SR tracks
- 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 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 "off"