Is Dolby Atmos the future of cinema sound?
10th Jul 2012 | 13:40
A huge change to movie audio
Disney Pixar's upcoming animated blockbuster Brave has been chosen to launch Dolby's latest cinema sound format, Dolby Atmos.
The revolutionary new audio system, which had its public debut in the US in June, introduces a ceiling array to the traditional surround speaker configuration and allows object-based sound design for the first time. Dolby describes the end result as the "illusion of an infinite number of speakers."
The choice of movie title seems serendipitous. Dolby's gamble on Atmos looks certain to make it the front runner in what is shaping up to be the most hotly contested evolution in cine-sonics since the advent of 5.1.
Four other companies (Barco, Immsound, Iosono and Illusonic 3D) have rival immersive audio solutions at various stages of development, all intended to complement the higher picture quality now being offered by 4K digital cinemas.
The stakes are high. The winner of this new surround sound format war could potentially dominate big screen audio for a generation, making $millions from studios, exhibitors and ultimately home video licensing.
Where to hear it
Dolby Atmos will make its public demo at the newly branded Dolby Theatre in Hollywood, home of the Academy Awards; the most prestigious of only 14 theatres in the US equipped to play the format.
The first commercial European cinema with the sound system is the Cinesa Diagonal Mar Screen 9, in Barcelona; unveiled this week for the first time, for the CineEurope 2012 trade expo.
The first UK cinema to get an upgrade to Dolby Atmos will be London's Empire, in Leicester Square; no launch date has been announced, but given that Brave opens in the UK on August 17, it's a fair bet that it'll be ready by then.
A game changer?
Stephen Field is the senior vice president for programs and products at Datasat Digital Entertainment (formerly DTS Digital Sound). He's more familiar than most with the next generation of 3D sound formats. Datasat makes the AP20 cinema sound processor, used in theatres worldwide, and has just launched a new high-end home cinema processor based on it, called the RS20i (yours for a cool £16k).
He told Tech Radar that systems such as Dolby Atmos not only change the way films are experienced, but fundamentally alter the way sound designers think about mixing movies.
''Suddenly every element in the frame becomes a separate sound object," he says "and the resulting soundtrack gets mixed on the fly at each and every cinema, depending on the speaker configuration in the theatre.
"If you have a hundred speakers down one wall, you can have the sound come from the exact speaker specified by the movie's sound designer. If that speaker fails, or you have far fewer speakers in an auditorium, then the system calculates where it needs to create a phantom speaker, so that the sound still appears in roughly the same space."
The process is called adaptive rendering. Dolby Atmos achieves this immersive innovation by combining additional sound channels with object based steering. Engineers can place an audio object anywhere spatially, with a precision impossible in conventional 5.1 mixes. The result is a more natural and immersive soundfield; the days of crude overhead pans are audio history.
Academy Award winning director Brad Bird was given a preview of Dolby Atmos earlier this year. He excitedly tweeted afterwards: "Was given a demo @ Dolby today of sequences from INCREDIBLES & MI:GP remixed in their brand new top secret system. KILLER."
Winning over Hollywood
Dolby is banking on the fact that mixing in Atmos doesn't impose significant time or creative penalties on a studio's existing workflow; after all, time is money. The post production process automatically creates 5.1 and 7.1 mixes of a movie, and it's these that are used for unmodified cinemas and home video distribution. The Atmos mantra is 'author once, optimise everywhere.'
However, equipping a cinema for immersive audio is an expensive business. A Dolby Atmos theatre employs two additional overhead speaker arrays, running front to back, which are used to create height effects. There are also additional surround speakers added to the sidewalls, with enclosures taken much closer to the screen than has been the norm previously.
However audio elements are not locked to any of these channels. Instead, they are stored with virtual position metadata and are assigned positions dynamically during playback, depending on the arrangement within a given theatre. Of course, not everyone agrees this is the best technology solution for better surround sound.
Dolby's closest competitor is Barco. Its rival Auro 11.1 system (expandable to 13.1) is channel, rather than object based - and it has some big Hollywood hitters behind it. The first movie mixed specifically for Auro 11.1 is George Lucas' WW2 action yarn Red Tails.
"With Auro 11.1 whatever is on that track, stays on that track. It doesn't vary. Nothing gets added or taken away from it," says Field. He confirms that Datasat has been working closely with Barco on a theatrical audio processor for Auro 11.1.
"We're developing software and a slot-in processing card for our AP20 cinema processor," he says. "When it's ready, we can then produce an upgrade card for our consumer RS20i processor." Barco definitely has aspirations to get its 11.1 sound system into the home market, he says.
Dolby, however, is certainly not talking about a home iteration of Atmos. Indeed, it's being pitched to theatre owners as a carrot to tempt punters away from their own home theatres, the aural equivalent of big-screen 3D visuals.
It's an understandable policy, says the man from Datasat. "Dolby first wants to maximise revenues by being the only supplier of cinema decoders. But I believe Dolby will expand the licensing of Dolby Atmos at some point. It will get its reoccurring revenue from the licence for film encodes, so it's in Dolby's interest to have the maximum number of audio processors able to play the format."
Field is quick to point out that the 16-channel Datasat RS20i is the only consumer audio processor currently upgradable to this new crop of cinema sound formats.
"It's a very simple upgrade procedure, too" he says. "You just slot in a board and the system immediately recognises the new hardware and knows what to do." Of course, installing a string of height channels and lining your living room walls with surround speakers may prove a tad more challenging…