FAQ for Moviegoers
Questions
1. What does Dolby analog film sound offer?
-Analog optical soundtracks playable in any 35 mm cinema in the world
-Soundtracks encoded with Dolby SR (spectral recording) for high fidelity
-Four-channel surround sound encoded onto two tracks on film, decoded back to four in the cinema
-Simple, economical system with good sound in its own right
-Effective backup for digital soundtracks
2. What does Dolby Digital film sound offer?
-Digital optical soundtrack data blocks located between sprocket holes
-Six-channel sound with separate left and right surrounds, plus low-frequency effects channel
-Greater dynamic range (soft to loud)
-Wider frequency range (bass to treble)
-Superior channel separation
-Analog Dolby SR track on print for compatibility and backup
3. What are the differences between digital film sound formats?
Dolby Digital, DTS, and SDDS differ primarily in the location of the digital soundtrack, and in how the digital audio is encoded.
4. Do the digital formats sound different?
The three digital formats are virtually indistinguishable, even under carefully controlled listening conditions. In actual exhibition, any differences are far smaller than the differences between cinema sound systems and acoustics.
5. Which format is most popular with the film industry?
Dolby Digital is by far the most popular format, with more cinemas equipped for Dolby Digital playback and more Dolby Digital titles in release. See recent screen counts.
6. Why is Dolby Digital so popular?
-Thrilling high-quality sound
-Ease of soundtrack preparation, print manufacture, and print distribution
-Comprehensive support from Dolby Laboratories for film producers and exhibitors worldwide
7. Isn't a soundtrack in the sprocket hole area particularly vulnerable?
No, extensive testing and thousands of hours of commercial exhibition have shown that a Dolby Digital soundtrack is not particularly susceptible to damage.
8. What happens to the soundtrack if the print is damaged?
Minor damage is handled by digital error-correction circuitry. In the rare event of serious damage, playback automatically switches to the analog Dolby SR track, then back to digital once the damage has passed.
9. Information encoded in Dolby Digital takes up less data space than other formats. Does this compromise the sound quality?
A coding system that uses a lower data rate is not automatically inferior to one using a higher rate. Digital movie soundtracks save space by storing only the data that's necessary to portray the original sound. This technique, called perceptual audio coding, is intended to capture the mix with just enough precision to sound the same as the original. The more powerful and well-designed the coding system, the more precisely it can shave bits without affecting the perceived sound quality. This means that some technologies, such as Dolby Digital, can sound just as good as others that use from two to four times as much data.
10. Is Dolby Digital available in the home?
You can now enjoy thrilling Dolby Digital sound at home from laser discs, DVD-Video and DVD-ROM discs, digital TV broadcasts, digital cable, and direct satellite broadcasts.
11. How many cinemas are equipped for Dolby Digital Surround EX playback?
Thousands of cinemas are equipped for Dolby Digital Surround EX playback. In fact, it's the most rapidly adopted new sound format in cinema history.
12. What is Dolby Digital Surround EX?
Dolby Digital Surround EX is a film sound technology that adds a center rear channel to the 5.1-channel Dolby Digital format. The center rear channel is reproduced by rear-wall surround speakers, while the left and right surround channels are reproduced by speakers on the side walls.
13. What does Dolby Digital Surround EX offer?
-More realistic flyover and fly-around effects.
-More effective movement of sounds onscreen or off to the sides of the screen.
-More stable image for atmospheres and music.
-More consistent surround effect throughout the auditorium.
14. Isn't Dolby Digital Surround EX just for action films with lots of big effects?
Dolby Digital Surround EX improves lifelike atmospheres and quiet effects, as well as "big" effects. With its more precise positioning of all sounds, Surround EX sound is not just louder or bigger, but more like real life.
15. What is THX?
THX® is a trademark that identifies a cinema's compliance with THX's parameters for cinema sound systems and acoustics. Unlike Dolby's focus on soundtrack formats, THX develops standards for the playback environment, regardless of film format. This is why a Dolby logo (identifying the film's soundtrack format) and the THX logo (identifying the cinema's THX certification) often appear on the same marquee or advertisement.
