The sound of Hollywood

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Dolby Laboratories relocated their Los Angeles office early last year to the heart of the Burbank Media District – a move that reflects the company’s commitment to the Hollywood entertainment community. The facility includes project and home theater rooms, conference rooms, event space, and a screening room.

As might be expected from a company with a major stake in motion picture audio, the 49-seat Larry Umlang Presentation Theatre II is a state-of-the-art screening room that incorporates the latest in equipment and acoustic design. The theater is named in honor of Dolby’s original Hollywood theatrical engineer, who died in 1988.

David W. Gray, vice president, Hollywood Film Division, explains that the theater’s design was determined not only by the need to keep sound in, but also by a wish to keep any airborne or structure-borne sound out. With its close proximity to the 134 Freeway, NBC TV’s helipad, and, most especially, Burbank Airport, isolation was certainly a challenge.

“It’s completely floating and isolated,” he explains, noting that the room sits on two-and-a-half inch Neoprene blocks. “Thicknesses of air gaps between the multiple walls were all determined based on the recordings.”

The screening room, designed by David R. Schwind of acoustic consultants Charles Salter & Associates, and Nick Ybarra and Max Williams of Rothenburg Sawasy Architects, the 1989 building’s original designers, plus Dolby’s Douglas Greenfield and Gray, incorporates classic acoustic practices. “My theories tend more to the old-time,” avers Gray.

In the projection booth, TASCAM MMR-8’s and DA-88’s accommodate dual-system work in the digital domain, and a dual mag machine handles double-system mag, with a custom switcher and a small Yamaha digital console for mixing, testing, and checks, such as A/B comparisons between master MOs and prints. A Crestron system provides remote control of the equipment via Ethernet.

Although all of Dolby’s current units are installed, the main screening room processor is the CP200. Dolby’s oldest still-working processor at nearly 21-years-old, it was chosen for its flexibility and handling of formats such as 70mm. Gray reports that what little EQ is being introduced is handled in the digital domain by the parametrics in the BSS crossovers.

The front three channels comprise custom JBL 3-way speaker assemblies that use design elements adapted from the cabinets installed at the previous Dolby screening room, as well as theaters at the Academy of Motion Picture Arts and Sciences and the Directors Guild. The close-coupled components utilize custom Neoprene gaskets and are sealed into a baffle wall that is specially constructed to tilt the components into the room at the correct angles and to minimize their distance from the microperf screen in order to reduce splash and high frequency rolloff.

For the three front channels, ported low-frequency cabinets, originally designed for the Academy by JBL’s Mark Gander, John Eargle, Greenfield, and Gray, each house four 15-inch speakers in a diamond pattern, equidistantly spaced. Response is smooth, and there’s virtually no lobing, Gray reports. A cluster of four 18-inch subwoofer speakers is positioned dead center, time-aligned to the center channel.

Multiple delay lines are also used to time-align the surrounds. “No matter where you sit, you’ve got surrounds that are blended together and in the correct time-alignment with the different screen channels. Pans work really, really well. It’s not cheap, but, in my opinion, it’s worth it!” Gray observes that Dolby took the opportunity to configure the room for future possible formats. The surrounds accommodate the three-channel rear of EX, and the room is wired for up to eight channels of surround. Additionally, two ceiling channels handle vertical height in a left-extra/right-extra configuration, “under the theory that it might be nice to get a mono image from the verticals, and if you’re far-left and -right you’ll never have a prayer,” says Gray. A center ceiling speaker was also installed.

“I’m personally convinced that four surround channels make a whole lot of sense,” states Gray. “The center is extremely effective. It’s the same with the verticals. But the question is, in the average motion picture, how much can they be used?” Time will tell.

Surround Professional Magazine