Multichannel audio has offered sound mixers, then and now, a larger palette to paint their sonic pictures. In the last twenty-two years, surround sound has evolved sonically and technically. Extra channels were added for more precise localization, bandwidth restrictions were removed to improve clarity and resolution. Moving from the cinema house to the home theater, multichannel audio is now commonplace.

Wishing to take theatrical sound a step closer to how humans actually hear, Academy Award®-winning sound designer and Director of Creative Operations for Skywalker Sound (Lucas Digital Ltd.), Gary Rydstrom, approached Dolby Labs and Lucasfilm THX to redefine existing theatrical sound system parameters. Initially his ideas were meet with opposition, believing such an ambitious endeavor would require a complete system redesign. However, once Dolby and THX took some time to consider the problem they realized the same results could be achieved with a simplified system enhancement.

The much anticipated Star Wars: Episode 1- The Phantom Menace will once again take visual effects to another level and launch, Dolby Digital - Surround EX, an enhancement to the existing theatrical sound format. Surround EX adds a center surround channel that is matrixed onto the discrete left and right surround channels. The addition may seem subtle but the effect is dramatic.

Before the advent of digital sound and five discrete tracks of audio, the surround channel was always a mono signal. Theaters placed speakers down each side of the auditorium just to ensure proper coverage. When current movies started mixing stereo surround, it didn’t dramatically effect speaker placement, but it did refine localization, though sound appeared to come from the left and right sides of the theater.

Rydstrom conceptualized that a separate rear surround channel would enable him to completely encircle theater audiences. This extra channel allows directors and sound mixers, like Rydstrom, a wider spatial field, improving surround articulation, and directionality. The back-to-front and front-to-back transitions in Phantom Menace, such as spaceship and pod racer flybys, are realistic and smooth. You don’t sense sounds jumping from point to point. Less effected by the width of the theater, ambient sound is more coherent, seeming to follow the main action accurately and fluidly. The new center surround speaker arrays also ensure viewers a better surround performance in off-axis seating.

Surround EX is fully compatible with all existing 5.1 digital formats (Dolby Digital, DTS and SDDS) and theater systems. The major add-on for theaters is Dolby’s SA-10 Surround Adapter. Prints that are encoded with Surround EX will playback in the standard 5.1 audio standard unless equipped with the SA-10, which is inserted between the theater’s digital sound system and power amplifiers. Staying competitive, DTS has introduced the DTS-ES decoder. It too is compatible with all other formats and according to their public relations firm, the DTS-ES black box is cheaper and easier to install than the SA-10 plus it can trigger dramatic effects, such as strobe lights and lasers. Just what do theater owner’s have planned for moviegoers in the next millennium?

Since Surround EX theaters must be equipped with speakers along the back wall, it may require a rewiring of the auditorium’s speaker array (left side, left back, right back and right side). Depending on the facility, the number and location of surround speakers may need to be updated and additional amplification may be applied to the rear loudspeaker group.

THX certified theaters were the easiest and least expensive to convert since they already place speakers in the rear of the theater. From the beginning, THX engineers found that rear placed speakers provided superior coverage even with mono ambient effects. Kurt Schwenk, Director of Professional THX confirms it was the fastest acceptance of any sound format in history. While it wasn't a requirement for theaters to convert to Surround EX, THX noticed a fast rate of conversion by existing clients due to their expectation to screen Star Wars: Episode 1-The Phantom Menace. They even picked up 150 theaters for a total of 3,000 screens worldwide.

Many more films are slated to include this new format including New Line's Austin Powers, The Spy Who Shagged Me, DreamWorks' The Haunting of Hill House, Pixar’s sequel to Toy Story and Sony's Memoirs of a Geisha. With so many theaters eager to convert, it will soon be the new standard in soundtrack mixes.

Just when you thought all your upgrades were behind you, in another year or two, we'll all want that extra channel of surround in our living rooms. Eventually, Star Wars: The Phantom Menace will be on DVD and we’ll want to hear it at home just as we did in the theater. You can bet it won’t be long before audio manufacturers will find a way to enhance existing home theater equipment. (Actually, Audio Design Associates already has a black box to enhance their Cinema Reference digital processor for an additional center surround though it is not an authorized EX decoder.)

When you check your local listing for the new Star Wars film, look for the new logo that indicates it's being presented in Surround EX. Having seen the film prior to worldwide release, I can tell you the soundtrack is definitely a major highlight. (See Abbie Bernstein’s review of Star Wars: Episode 1 - The Phantom Menace.)

title:	Star Wars Ushers In Surround EX
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