[Steve Withers]

In the second Dolby article, Steve Withers takes a closer look at their revolutionary new sound system

One of the main reasons for our recent visit to Dolby’s facility in Royal Wootton Bassett was that the primary screening room is currently one of the few places in the UK where you can experience Dolby Atmos. What is Dolby Atmos? Well in simple terms it’s a completely different approach to film sound design and delivery, that moves away from the traditional channel based approach and instead introduces the concept of ‘objects’ or individual sounds that can be manipulated in three dimensional space. The result is that sound designers now have an unprecedented degree of freedom as they move sounds around the auditorium, whether it’s from front to back, side to side or even overhead. How is this done? Well let’s find out...

Walking into Screening Room 1, you immediately realise that you’re not in a normal cinema when you look up and see two arrays of speakers running overhead. You also notice that these speakers run from right up next to the screen all the way to the back wall, as do the side speakers, although is isn’t as obvious because they are built into the walls. All these extra speakers are one of the reasons for the greater immersion that Dolby Atmos offers and their position along the entire side wall allows for seamless pans from front to back. However there is more to Dolby Atmos than just extra speakers because the way a Dolby Atmos track is mixed and delivered is radically different from the traditional approach.

Screening Room 1 - Dolby Atmos Conversion

Currently a sound designer will mix a film soundtrack using five discrete channels - front left, front centre, front right, side right and side left - along with a LFE (Low Frequency Effects) channel which is the point one in a 5.1 surround mix. Even today the majority of films are still mixed in 5.1, although as mentioned in the previous article Dolby launched Dolby Surround 7.1 in 2010, so now there are a sizable number of films being mixed in seven channels. These 7.1 mixes add an additional two channels to the existing 5.1 mix and these channels represent rear left and rear right. There are competing next generation audio formats currently being developed for the cinema but unlike Dolby Atmos, those sound systems are still based on the concept of additional channels, either 11.2 or 13.2 in total.

Screening Room 1

Dolby’s approach is completely different and it uses the concept of building soundtracks using objects, which equate to individual sounds or channels. From these 128 objects or channels, up to 10 can be allocated to the ‘bed’ which is the basic 7.1 or 9.1 mix, whilst the remaining 118 can be used for specific objects. At present sound designers are using between 30 and 40 objects but theoretically they could use up the the maximum 128, if they wanted to create an 'objects-only' mix. This will fundamentally change how sound designers think about mixing movies because suddenly every element in the frame is a separate sound object. The problem at the moment is that the initial 5.1/7.1 mix is being produced and then the Dolby Atmos mix is being created by adding objects, thus extending what are already tight post-production schedules for films. What Dolby ultimately hope to achieve is the introduction of the Dolby Atmos Workflow where the initial objects mix is automatically rendered down to either a 5.1 or 7.1 bed for use in unconverted cinemas or for home video distribution. The Dolby Atmos mantra is 'author once, optimise everywhere.'

Screening Room 1 - Dolby Atmos Equipment Rack

The other major difference is how Dolby Atmos is delivered in the cinema, starting with the additional speakers. There’s no doubt that upgrading a cinema to Dolby Atmos won’t be cheap as you have to add the two overhead speaker arrays, along with additional side speakers that go right up to the screen. The specifications also call for full-range speakers to be used all around and the addition of two subwoofers at the rear in order to bass manage the surrounds. However it isn’t just a case of adding more speakers or additional channels of amplification because the way that Dolby Atmos renders the objects in the mix can give the impression of far more speakers than are actually in the cinema.

Screen Adjacent Height Speakers

This is achieved through a process called adaptive rendering, which starts by accurately modelling the cinema - the dimensions, the number of speakers, their exact positions, their power specifications - and then rendering the Dolby Atmos mix in the best possible playback so that it’s optimised to that specific cinema. This is possible because the audio elements are not locked to any specific channel but are stored with virtual position metadata and are assigned positions dynamically during playback, depending on the arrangement within a given cinema. This adaptive rendering is done on-the-fly but if there is a speaker where the object is supposed to go then it is used, if not then the Dolby Atmos processor will create a phantom speaker, thus effectively placing the sound in the correct place and creating the illusion of an infinite number of speakers.

Height Speaker Array

The combination of additional channels and speakers, along with adaptive rendering that allows for object based steering results in an incredibly natural and immersive soundfield. Sound designers can place an object anywhere within a three dimensional space, with a precision impossible with conventional 5.1 mixes, resulting in incredibly smooth pans. To prove this, we were sat at the sweet spot and Nick Watson, a senior engineer at Dolby, played a 5.1 audio-only mix of a man with a guitar walking around the room. In 5.1 there were clearly gaps as he walked from front left to side left and then across to side right. However in Dolby Atmos this was smooth and seamless and the result was the sound of a man playing a guitar as he walked around you. Nick then played another audio-only piece that was a rain hitting a tin roof above you, which used a 7.1 bed with additional objects. The result was incredibly realistic and having spent years living in Hong Kong we were very familiar with monsoon rains, the acoustic effect was positively transportive it was so natural.

Rear Speaker Array & Nick Watson

After that we moved on to two specially created Dolby Atmos trailers, the first of which is called ‘Unfold’, which is an object-only mix created by the sound designer for Transformers: Dark of the Moon. The sound mix was created first and then the visuals were added, so the sound designer had complete freedom to do whatever he liked and use Dolby Atmos to its full potential. The results, whilst somewhat reminiscent of Transformers, were stunning as the sound effects just surrounded and completely immersed you. The monitor on the desk showed the Dolby Atmos adaptive rendering in action as objects were being moved around the wireframe model of the screening room. There were objects being moved around the model that you could clearly hear being rendered in the room and it was, quite simply, the most active sound mix we have ever heard. There was a second trailer called 'Leaf' that totally immersed you in a forest, surrounding you with sounds from the sides, above and behind, with seamless panning around the room. It was a more subtle and thus far more realistic effect than the first trailer but both were breathtaking.

Dolby Atmos Adaptive Rendering & Room Modelling

Then we moved on to some film soundtracks, the first of which was Rise of the Planet of the Apes, which had been remixed in Dolby Atmos. The sequence we watched was the battle on the Golden Gate Bridge and first we watched the playback without the 7.1 bed, just hearing the objects which consisted of sounds like bullet hits, roars, helicopters and the like. Then we watched it with both the 7.1 bed and the objects and you could hear how the sound designer was using the objects to augment certain effects or to precisely steer sounds around the room. The second scene was from Taken 2, which was the second film released with a Dolby Atmos soundtrack and here the sound designers had used the objects in an imaginative way. In the scene Liam Neeson's character had been kidnapped with a bag over his head but he's listening for audio clues to where the kidnappers are taking him. When away from the inside of the van it was just the 7.1 bed but whenever the camera cut to Neeson's acoustic point of view the soundtrack filled with audio cues being move around the soundfield.

Empire Leicester Square - Dolby Atmos Conversion

The potential for the creative use Dolby Atmos is immense and aside from the obvious action beats it offers the ability to produce far more atmospheric soundtracks. In Brave, the first film to be released with a Dolby Atmos soundtrack, there is extensive narration which the sound designers mixed out from the edges of the screen to make it more expansive to match the widescreen 3D visuals. One can only imagine how effective Dolby Atmos would be if used in a horror film! Dolby has taken the view that the best way to launch Atmos is to generate support amongst the content creators, as they feel this will then motivate the cinema chains to upgrade their theatres. Perhaps unsurprisingly, the first studio to embrace Dolby Atmos was Disney.Pixar who used the system when mixing Brave. The studio had previously been the first to use Dolby Surround 7.1 with Toy Story 3 back in 2010 and given that an animated film’s soundtrack is created from the ground up, Brave provided the perfect test bed for Dolby Atmos and its object based approach. Since then, there has been Taken 2, Legend of the Guardians, Life of Pi and The Hobbit: An Unexpected Journey. Peter Jackson in particular has been a big proponent of Dolby Atmos and his Park Road post-production facilities in Wellington can now mix in the format. Jackson feels that Dolby Atmos is the pefect companion to the widescreen, high frame, 3D visuals he has created for The Hobbit. In terms of Dolby Atmos equipped cinemas in the UK, the first is The Empire in London's Leicester Square but more will be opening in 2013.

The Empire Leicester Square

The Holy Grail of cinema distribution is the single inventory solution where everything comes in one package. That was the case with 35mm where the image and all the soundtracks where on the film itself, which made distribution much simpler and multi-format audio far easier to implement. Dolby believes that they too can offer a one-stop solution and thus become the main supplier of digital cinema packages and decoders. It’s a high stakes game where the rewards are significant but Dolby already have the brand recognition that might give them the edge. Whatever the eventual outcome, there's no denying the technological achievement that Dolby Atmos represents and once again Dolby are heping to push cinema sound to the next level.


We interview Guy Hawley from Dolby about Atmos in this month's Home Cinema Podcast

01:02:36 - Dolby Atmos interview with Guy Hawley

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[alextheg]

Absolutely amazing. Sounds like Dolby may have really nailed it. Can't wait to experience Atmos. I'm curios how this will filter down into my living room though ?

[Steve Withers]

Originally Posted by alextheg

I'm curios how this will filter down into my living room though?

Me too!

[alextheg]

For me, the introduction of Atmos is far more important than say 3D. The improvement in sound technology such as Atmos will immerse the viewer far more .

[technoman28]

Very interesting article, but a question that strikes me is, did you get the opportunity to sit in an area that wasn't in the sweet spot during any of the demo's? and if so, what was the experience like there?

[Steve Withers]

One of the reasons for having additional speakers along the entire length of the side and rear walls is to improve the experience for as many people as possible, regardless of where they are sat. Having said that I spent the whole demo sat at the control desk, so I can't actually confirm that.

However I'm with Stanley Kubrick when it comes to going to the cinema, there are are usually only two seats worth sitting in and if I can't get one of those, I don't go.

[Dan201]

It sounds good but what exactly is an 'object'? I understand they can move sounds around such as bullet shots but they will be present in the conventional 7.1 so what sound objects will actually be added?

[DTS MAN]

Originally Posted by alextheg

Absolutely amazing. Sounds like Dolby may have really nailed it. Can't wait to experience Atmos. I'm curios how this will filter down into my living room though ?

Me too and horror films...no way!

2 great articles. Thanks

[technoman28]

I don't claim to know for certain, but I think it would be the ability to place a sound anywhere within the room, such as a helicopter above your head for example. I think it has been done to a lesser extent with multi channel audio, but this system would i imagine make it a lot easier and more accurate in making a sound tie in with the visual positioning of the image, and as Steve said the transition from front to back, (or vice versa), would be infinitely more realistic.

I imagine it being an extremely immersive technology and can't wait to experience it.

[alextheg]

Originally Posted by technoman28

I don't claim to know for certain, but I think it would be the ability to place a sound anywhere within the room, such as a helicopter above your head for example. I think it has been done to a lesser extent with multi channel audio, but this system would i imagine make it a lot easier and more accurate in making a sound tie in with the visual positioning of the image, and as Steve said the transition from front to back, (or vice versa), would be infinitely more realistic.

I imagine it being an extremely immersive technology and can't wait to experience it.

That's about the way i understand it.

Think of it this way, instead of squeezing all that sound into 5.1 / 7.1 ... you have 128 audio channels to mix with . Each sound getting its own channel , allowing the sound engineer to mix the audio much more precisely and with much better definition.

[Steve Withers]

That's correct, the way that soundtracks will ultimately be mixed is as a full Atmos mix from which they will render down the 7.1 'bed' but this will not include all the objects (sounds) used in the full Atmos mix. For example, the 'Unfold' trailer is an object-only mix with no 7.1 or 5.1 component at all, although most of the other demos I heard were 7.1 'beds' with additional objects on top. As I said in the article I first I heard the Rise of the Planet of the Apes soundtrack with just the objects playing and none of the 7.1 'bed' and then I heard it with the two combined.

[Steve Withers]

Originally Posted by technoman28

I don't claim to know for certain, but I think it would be the ability to place a sound anywhere within the room, such as a helicopter above your head for example.

Exactly, a helicopter did go over my head in the ROTPOTA clip and the clear and precise imaging combined with three dimensional steering was incredibly visceral. I obviously don't get many helicopters flying over my head in real life but I've been in plenty of thunder storms and the 'Rain' demo was staggeringly realistic. As I said in the article it transports you in a way that normal 7.1 surround just doesn't, you are no longer aware of sound effects, you're just totally immersed by the soundtrack.

[Dan201]

So these extra sounds won't be heard in a cinema that doesn't have the upgrade. Pretty much means it can't be any significant sound as it will be badly missed.

Unless i'm missing something, which I probably am.

[Steve Withers]

Well I'm assuming all the sounds meant for the height speaker arrays will be lost in a normal 5.1/7.1 mix but rather than specific sounds, what you'll loose is the greater sense of dimensionality, the smooth pans and more precise steering and imaging. I'm seeing The Hobbit in a normal cinema on the 13th of December and at an industry screening on the 22nd which will be in Dolby Atmos, Dolby 3D and 48HFR, so that will give me a point of comparison.

[Dan201]

Id love to hear your opinion on all the differences of those showings.

[Steve Withers]

After seeing the The Hobbit on the 13th (RealD, 24fps, 5.1) and then on the 22nd (Dolby 3D, Dolby Atmos and 48HFR), I'll write an article comparing all the different technologies.

[Doomlord_uk]

I want to see how this is going to be used by game designers. I imagine the live processing requirements for DA sound tracks/sound effects will be prodigious and we might be waiting for next-next-gen hardware for this to happen at home (although PC sound cards could implement it anytime I guess?).

I have to say, as with IMAX technology this may prove to be a reason to prefer going out to see a film rather than seeing it at home (if you have a good home cinema setup). Mostly I loathe going to cinemas - too many annoying people, crappy catering (if you're going to sell food, sell something decent ***) and volume levels that leave my ears ringing afterwards... But occasionally the art and the technology come together to make it all worthwhile. That might happen more often with Dolby Atmos.

btw, what is 48HFR? an upgraded version of 24fps playback?

[Steve Withers]

The Hobbit was shot at 48 frames per a second as opposed to the usual 24 and Warners are referring to it as 3D HFR (High Frame Rate). I've been reading some early reviews of The Hobbit and it sounds as though certain action scenes benefit from the higher frame rate but interior scenes look more like expensive video. I'll reserve judgement until I've seen 3D HFR for myself but I have concerns about the use of a higher frame rate.

[Dan201]

It must all be in an attempt to get us back to the cinema.

3D didn't do it for the masses and can already be had at home but I can't see Atmos making to the home in the same way so it could be sound and not video that gets us back to our local cinemas.

[Wilseus]

This sounds good but I'd rather have a decent sound system in my local cinema using technology that's already out there than a new system that I'd have to go to London to experience. How many THX certified cinemas are there in the UK? There was just one the last time I checked!

[Steve Withers]

Dolby are still beta testing Atmos, it doesn't officially launch until the spring but don't worry there will be plenty of Atmos equipped cinemas this time next year.

[alextheg]

I listened to the Podcast today and im all the more excited to hear Atmos in action. After listening to Guy Hawley im convinced this is really going to give the cinema experience the upper hand.

Reading between the lines id say Atmos will not be feasible in the home , at least for the majority of us. The complexity and the hardware; for example the amount of speakers will i think make it out of reach. This i feel will make the cinema special once again.

[Dan201]

I can see a home version involving more height chanels rather than ceiling ones. Or possibly using a couple of in ceiling speakers.

[alextheg]

Im not sure, although i would be inclined to consider extra speakers at the sides or rear. As you know , we can do this already with 7.1 / 9..1 receivers and this obviously is going to make a considerable difference to the sound field.

We can already achieve the base of Atmos ie; the 7.1 soundtrack. Its the speaker arrays thats the clincher not the channels. Yes Dolby have added channels to the mix , its what they've done with them thats important. For example in the cinema they can use upto 64 outputs. Its a colossal amount of speakers. No wonder its immersive.

Once you try and water that down and squeeze it into the home theatre im not sure you will get the effect of Atmos. Most of us can do 5.1 but 7.1 and above thats a different story........ Im not saying i would'nt welcome the technology upgrade i would, I just dont see how they're going to do it.

Besides , i only just buried all my existing cables in the walls a few months ago.........is that the wife calling ?

[Doomlord_uk]

I think it will be easy to add extra speakers in the home for Dolby Atmos, as long as we don't get hung up over size, power ratings etc. Overhead speakers would just need to be ceiling speakers, they're neither expensive nor particularly problematic aesthetically. Once fitted, anyway. I can absolutely see Atmos coming to future homes...

As for 3D bringing us back to the cinema - it has, for me; my only reservations are that there is considerable variation in how well it is done, and the cheapo glasses they give out suck. I'm seriously thinking of buying some fancy Real3D glasses for the cinema though, which I hope will improve my enjoyment of 3D films more.

All new tech takes time to mature, spread and become widely accepted and for creative people to learn how to get the best out of it. And by the time they have, I would think it would also finally have become affordable. So I'm certainly looking forward to hearing this both in the cinema and at home eventually too.

[Steve Withers]

I'm sure that Dolby will ultimately release a home version of Atmos that uses DSP to replicate the improved steering, we're already seeing a variation of that with DTS Neo: X that creates a pseudo 11.1 configuration from 7.1 speakers.

Investing in a decent pair of RealD glasses is a good idea, I was lucky enough to receive a designer pair from LG that are very light and use real glass, it definitely improves my experience at the cinema.

[Jon P]

Someone should make a mock up of a atmos home cinema in a normal living room. Bolting that many full range speakers in a living room would look hysterical. Maybe oneof the speaker companies could do it for April fools. Stick 1 full range speaker on my ceiling and I'd have to duck.
The very concept is amazing I've installed 11.2 home cinema and that does create a very different experience but actually having the independent channels/objects must be totally immersive.
Maybe when cinemas upgrade to atmos they could fix some of their other flaws at the same time. Projectors that shake and walls between cinemas that aren't able to keep out noise are things that plague my local cinema.

[phow]

For anyone interested. "Life of Pi" is showing now at the Empire Leicester Square (London) screen 1 in Atmos.
I went to see (and hear) it last night. All I can say is it was a Jaw dropping experience, they showed the "leaf" trailer before the movie and the feeling was similar to the first time I heard 5.1 off a Laserdisc (Chain Reaction) in a proper demo room many years ago.

As the Empire is a large room intricate sounds with 5.1 tend to get lost especially in the surround channels but with Atmos everything was prescise all around.
The screen speakers blended seamlessly with the sides, rears...the overhead channels during the rain, storm and a few other scenes (without wanting to give any spoilers). Again the soundfield blended together to bring the audiotrack to life.

Can't wait to see the next Atmos movie that will be shown at the Empire. I wonder what other Cinema chains in the UK are planning an Atmos installation in 2013 and where? Perhaps the "Vue extreme screens" maybe???

[Steve Withers]

I saw the trailer for 'Life of Pi' in 3D last night and whilst that kind of spiritual claptrap isn't my cup of tea, the 3D looked amazing, so it must have been awesome with Dolby Atmos. Speaking of 'The Hobbit', I'm seeing it in Dolby Atmos at a special screening at The Empire on the 22nd of December, which should be interesting.

[Dan201]

Spare ticket Steve?