Dolby Atmos: Installing the sound of science

posted on Tuesday, 3rd February 2015 by Steve May

home cinema  ISE  Dolby Atmos 


Dolby Atmos has taken an early lead in the nascent 3D home audio market, allowing consumers to experience the precision and power of object-based audio in their own home theatres. Unlike previous cul-de-sac home audio embellishments like Pro Logic II, Audyssey DSX and DTS Neo:X, the new format appears to offer listeners a genuinely new sonic experience, as more and more movies are mixed using the technology. But getting traction in the commercial cinema world has been far from easy, and consumer awareness remains low.

A typical commercial Atmos speaker array will comprise a full 360 degree enclosure, with additional ceiling speakers. In the home, this distils down neatly to a 5.1.2 (five main channels, one LFE and two heights) or 5.1.4 speaker configuration (additional subwoofer chanels are, of course de rigueu). Both provide a compelling alternative to regular surround sound, creating a great opportunity for custom installers. So much so, that Dolby will be exhibiting at ISE for the first time, offering visitors an insight into the Atmos experience.

At ISE, Brett Crockett, Senior Director of Sound Technology Research, and Stephen Auld, Senior Manager, Broadcast and Licensing, will be holding demos and explaining how the technology works, what’s needed to deploy it in a home theatre, and how AV installers can leverage it to boost sales.

By way of a precursor to this, Inside CI presents this exclusive interview with brand evangelist Jonathan Jowitt (pictured below), in which he talks candidly about the sound format and its journey from commercial cinema to home theatre. (Shortly after completing this interview, Jonathan Jowitt left his position at Dolby.)

JJ Cropped

To date, more than 120 movies have been mixed in Atmos, and the first few are already appearing on Blu-ray (most notably Transformers Age of Extinction, Teenage Mutant Ninja Turtles, Expendables 3, and soon Gravity). This conversion from cinema to home has been made possible by an innovative Spatial Coding technique, which takes into account the location of sound objects in the original theatrical mix and more efficiently encodes them, so that they can be incorporated within Dolby TrueHD for Blu-ray and Dolby Digital Plus, for OTT broadcast and VoD services.

Of course, Dolby doesn’t have the next generation home cinema market entirely to itself. Auro-3D, created by Belgium-based Auro Technologies, has also garnered studio support, at least theatrically. Its proposition is more conventionally channel-based and mandates a two-tier speaker stack (imagine a traditional 5.1 layout with a second tier of four more speakers fore and aft, complete with Voice of God ceiling speaker). It too offers an all-encompassing surround sound experience. Launching this March is DTS:X, a rival object-based sound system from Dolby’s traditional nemesis. For AV theatre builders, things are starting to sound very interesting indeed...

Atmos On Label (1)

We’re already starting to see Atmos impact on AVRs, but the theatrical business appears to be a slow burn. Is there any particular reason for this? 

Jonathan Jowitt: “If you think about the cinema owner, the exhibitor, you have to choose a week when you haven’t got a blockbuster in, because it will take us a week to get the wiring done, the speakers in, then tested and calibrated. And what happens if you’ve only just put speakers in? You have to think about the normal lifecycle of a cinema; some cinemas are waiting until their refurb window, while other chains were cautiously waiting to check whether Atmos was going to be successful. We’re a US centric company so we look at the global rollout. There might only be nine Atmos screens in the UK (at the time of writing), but some countries are ahead of others.”

How big is the Dolby Atmos phenomenon globally?

Jowitt: “We’ve now got over 660 screening rooms around the globe, in 40 different territories. It’s been very popular in Bollywood. Mubai has four Dolby Atmos screens, which shows you how global this technology is. Ironically we’ve had more Atmos installations in countries where digital cinema hasn’t been that established in the first place. They went from analogue cinema to Dolby Atmos. They missed out the first digital cinema phase. People who had initially invested big in digital cinema, such as the UK, created an Atmos inertia. But we’re prepared to put up with everybody’s timelines. What it’s allowed us to do is improve the technology and bring the cost of deployment down.”

Just how different is Atmos to surround systems that have been around for the past twenty years or so?

Jowitt: “It works very differently to any cinema sound system you’ve heard before. Most cinemas today will use Dolby 5.1. We’ve gone back to the drawing board with Atmos, treating the sound as individual objects that can be placed in any part of a 3D space at any moment in time. It’s not channel based, so scales to any size room. So your room can be a 70-seater or a 400-seater. It scales naturally into that space, because the audio renderer knows where the sound needs to be in space, and knows the space it’s playing into. It’s very different from 5.1 in your home cinema.”

So a professional Atmos cinema installation is a little more complicated than deploying Atmos in the home?

Jowitt: “Our object based bitstream has lots of channels, all in mono, each one of them having complimentary X,Y and Z information. These are scalable. You have to tell the renderer how many speakers you have and where they are. You also tell the renderer the XYZ coordinates and the angle they’re tilted at. It then does a calibration pass, where it sets the amplitude. When you’re happy with the amplitude, you then do the EQ. And the process repeats. It takes a whale of a time.”

How does Atmos perform in a larger commercial space, compared to a smaller residential one?

Jowitt: “Consider the refurbished Empire in London’s Leicester Square. The new cinema is great, we’re really pleased with how it sounds. The original screen was a 1300 seater, the replacement is 400. The question with any speaker configuration, with Dolby or anybody else is where are the hotspots?”

When it comes to Dolby Atmos where will you find the best seats in the house?

Jowitt: “It’s not going to be at the very front row or at the very back. It never will be, no matter what speaker system you’re using. The Dolby Theatre on Highland, pictured below,  (formerly the Kodak, and home to The Academy Awards) has around 200 speakers, all individually amped - and we’ve had to gang three renderers together, each render can output 64 channels. This trio or renders give you 180-odd feeds, so it’s arranged so that one render feeds one Gallery, while another feeds the Gallery below with exactly the same feed. In such a large space it’s always a compromise.”

Dolby Theatre _Before Unveil Small

Lifting Dolby Theatre Screen Small

Dolby Atmos Speaker Trusses Small

How difficult has it been to get hardware support for the theatrical side of the business?

Jowitt: “In the early days, Atmos was almost like a bespoke system. It’s now coming off the production line faster. We have more speaker manufacturers to give exhibitors a wider range of speakers. Everybody wants to make Atmos speakers as they see it as way to make revenue; whereas in the past you might have put three speakers across the front, three down the sides and a couple across the back, they’re now selling nearly ten times that for every room.”

ISE 2015 Dolby Atmos demos run daily in Hall 7, Booth 7-X170, between 9am – 5.30pm. ISE runs February 10-12 at the Amsterdam RAI

Steve May

Inside CI Editor Steve May is a freelance technology specialist who also writes for T3TechRadarHome Cinema Choice, Trusted Reviews and The Luxe Review.

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