Analog Sound

Dolby SR

1. Dolby Spectral Recording units decode analog sound. They use four audio channels. These channels are left, right, center, and surround. Its like SRD without the Digital. Essentially, SR's the highest grade of analog sound. The benefits over Dolby A are deeper bass and clearer highs.
   

   Dolby A

2. Dolby A remains the universal stereo format that almost all theaters can play. Star Wars: A New Hope claims the title of being the second film released in this sound format. Dolby A is the lowest grade 4 channel stereo sound. These units can play Dolby SR soundtracks with a loss of sound depth and volume. There are different brands that can play Dolby encoded prints. Two examples are Kintec and Ultrastereo.
   

   Ultrastereo

3. Ultrastereo competes with Dolby on encoding analog soundtracks. Movies that use the Ultrastereo sound format sound fine in a Dolby equipped theater. Unfortunately, a Dolby print playing in an Ultrastereo equipped theater isn't the same.
   Depending on the type of movie, sound quality may not be a priority. When Harry Met Sally in SDDS and Independence Day in Dolby A seem universally wrong.
   Personally, I'd still rather see Harry meeting Sally in digital.
   

   Mono

4. Monaural signifies one sound channel. Leave real quick if you run into a stereo movie playing in a mono theater.
   

Sound format represents one part of audio reproduction. Auditorium acoustics, quality speakers, and well trained projection staff help ensure a great experience.