Inside Dolby Surround 7.1 Page 3
I did notice a few apparently discrete back surround effects-distant crashes and other incidental sounds coming specifically from one or the other of the back surrounds. But just as with most of the relatively rare 7.1 soundtracks available on Blu-ray Disc, the improvement over 5.1 wasn't dramatic.
Theater sound expert Tomlinson Holman-a founder of Audyssey Labs and THX-concurred in a recent post on the Audyssey website blog. According to Holman, "Having more surround than screen channels, for instance, is a little weird, since our perception of localization is better in front than back. But more channels are always merrier and welcome to the fold." Asked to elaborate, Holman told S+V that he couldn't expand much on his original comment without getting into technical arcana, but hinted that he may blog further on the subject in the future.
Asked to cite specific examples of a Dolby Surround 7.1 magic moment, Bowling suggested the scene in TS3 in which Ken meets Barbie. Sound re-recording mixer Michael Semanick started with the classic Gary Wright tune "Dream Weaver" in stereo, then mixed it out to 7.1 to envelop the audience. I remember that scene, and the music expanding to fill the theater, but I'm left wondering if the effect would have been much less magical in, say, Dolby Digital Surround EX, which decodes a single extra surround channel from the existing left and right surrounds in 5.1. Unfortunately, I couldn't back up the movie and watch the scene again-not even at Gold Class Cinemas.
Bringing it home
Even if Dolby Surround 7.1 doesn't deliver a huge payoff in the theater, it may hold benefit for Blu-ray fans, who are of course always free to back up the movie and hear that scene again. Currently, there aren't many 7.1 soundtracks available on Blu-ray, in large part because movie surround sound is mixed for 5.1 or Surround EX theaters, and doing a special 7.1 mix for the Blu-ray Disc costs more and takes more time. Now that commercial cinemas can play the 7.1 mixes, there's more reason for studios to produce them.
"With more discrete 7.1 mixes made from the original feature film mix, there is more incentive for studios to bring this original mix to Blu-ray," Bowling said. But of course, there's no guarantee this will happen. "Inevitably, it is up to the home video departments of studios to make the final decision on what will be incorporated into Blu-ray releases," he added.