Titles: Margouleff is CEO; Biles is president and chief engineerBlu-ray technology includes specifications for 7.1-channel digital audio, adding one speaker to each side of a traditional 5.1 home theater setup . The vast majority of Blu-ray releases so far have only been 5.1, but the Hollywood boutique run by former music-industry sound guys Robert Margouleff and Brant Biles has been out in front of the curve with a number of 7.1 sound mixes. Each of these share the duo’s philosophy of music industry mixing: Design for the environment where you’ll be heard. “When I first listened to DVD sound, I thought it was terrible,” says Margouleff, who won a Grammy in 1974 for engineering on Stevie Wonder’s “Innervisions.” “They were giving you a theatrical mix for a living room.” Mi Casa is set up as a boutique facility in a large Spanish-style house where directors can hear the sound mix for their films in a home theater environment. Guillermo del Toro and Terrence Malik are just two of the helmers who’ve worked at the site. The company has had a hand in dozens of New Line discs including “The Orphanage” and “The Golden Compass.” “We’re usually given 5.1 stems, and then we create 6.1 or 7.1 stems from that,” Biles says. “We can give directors a lot of options.” While some might question the necessity of doing 7.1 given the currently small size of the elite 7.1 market, Margouleff believes audio must equal the high-definition screens invading home theaters. “We’re moving toward a 3-D picture in the home,” he explains. “People don’t want sound lagging behind, and the more people who want it, the more affordable it becomes.” POV: “I always want to be on the bloody cutting edge of the technology,” Margouleff says.