Making its way from film sets and post-production suites all the way into living rooms, Dolby's Atmos surround sound technology has quickly become one of the most important and impressive technologies in home cinema.
Over the past few years, Dolby Atmos has transitioned from the "future of home cinema audio" to very much the here and now. That’s not only thanks to the immersive surround sound technology gaining traction in Hollywood, but also its support throughout the chain - it runs from content creation and distribution right the way through to hardware and device support.
While it's still not part of every cinema experience in the UK, the good news is you can now enjoy the Dolby Atmos experience at home - whether that’s through an Atmos-enabled AV receiver and speaker package, or through an Atmos soundbar.
But what exactly is Dolby Atmos? And what kit do you need to get involved? Allow us to explain...
What is Dolby Atmos?
Atmos is, in Dolby's own words, "the most significant development in cinema audio since surround-sound." And we'd have to agree, really (whilst also recognising that rival DTS:X - a similar object-based surround technology - is also making headway).
Atmos is a surround-sound technology that was originally developed in 2012. It expands upon the current 5.1 and 7.1 surround-sound set-ups with surround channels coming from overhead.
Speakers have been placed along walls (at all heights) and even behind the screen itself, but the crucial point about Atmos is that you can place speakers in the ceiling, enveloping the audience in a dome of sound.
Up to 400 speakers can be used in the top Dolby Atmos cinemas, but in a domestic environment it's unlikely you'll have the room (or the desire) to house such a system.
Instead, there are a number of simpler options: the addition of two or four ceiling speakers in your system; installing add-on speaker modules on top of your existing main floorstanding or bookshelf front left/right speakers (one set, for a .2 configuration) or your left/right front and rear/surround speakers (two sets, for a .4 configuration); or the purchase of a purpose-built Atmos speaker system.
When a Dolby Atmos system is installed, the room receives a complete calibration, allowing sound mixers to precisely ‘place’ sounds and voices at exact points in the soundfield rather than just to specific channels. Each speaker in an Atmos system has its own discrete feed, enabling new front-, surround- and ceiling-mounted height channels.
Dolby Atmos in the home
Given that a cinema-style installation isn't a practical solution for most people, AV manufacturers have stepped in to make it realistic in the domestic situation - and even, in some cases, affordable.
And you have options. The golden path starts with a compatible AV receiver with the ability to decode an Atmos soundtrack. Most receivers that have come to market in the past couple of years support the format – even at the budget end – including all of the most recent What Hi-Fi Award-winners.
The best news: domestic arguments aren’t necessary as you don't have to make holes in your ceiling for installing in-ceiling speakers. Atmos speaker packages often incorporate upward-firing drivers into their front speakers - so that sound is reflected off the ceiling and towards your listening position to create a pseudo-overhead effect.
Pioneer was one of the first out of the blocks with a complete Atmos speaker package, the S-73A, in 2014 - and it's since been joined by the likes of Klipsch, Focal, Jamo, Elac and others. There's even a wireless Atmos speaker system, thanks to Damson's S-Series (although the £650 system is not quite in the same league as the packages mentioned above!).
Atmos can also work with existing home cinema systems. Dolby Atmos-enabled speaker modules are available - when placed on top of your speakers, they allow your system to deliver Dolby Atmos sound from a compatible AV receiver.
KEF is one such brand, with its Q50a and R8a modules. The modules aren't limited to being used with KEF speakers - it can be placed on top of any speakers you already own. AV Industry brands Elipson, Tangent and Eltax have all announced new, budget (from £150) Atmos modules too.
Dedicated Atmos speaker packages are still in relatively short supply, though, which brings us to Option Two: Dolby Atmos soundbars. They tend to use upward-firing drivers to disperse sound overhead. So far, the Sony HT-ST5000 has seriously impressed, as has Sennheiser's stunning, but pricey, Ambeo Soundbar.
As for Blu-ray players, Dolby says you don't need a brand new player to support Atmos, just as long as your player fully conforms to the latest specifications and can output a bitstream audio signal for your AV receiver to decode.
Now, TVs (such as LG's 2017, 2018 and 2019 and 2020 OLED models) support Atmos too. It's not quite the same as having a room full of speakers, and most TV's can't fire audio overhead, but LG claims the general quality of audio is still an improvement over a standard stereo signal.
In 2019, Panasonic introduced the five-star GZ2000 4K OLED TV, which does have its own upward-firing Dolby Atmos speakers built into the rear of the set. It's one of the most impressive OLED TVs we've tested. More recently, OnePlus announced plans to join the party, courtesy of an eight-speaker OLED TV with Atmos support.
Dolby Atmos Height Virtualization
No Atmos speaker set-up or soundbar, no Atmos experience? Not quite. In realising that not everyone can afford dedicated Atmos speakers/soundbars - and no doubt in an effort to expand the reach of the technology - Dolby has created processing designed to create a ‘virtual’ Atmos experience from regular, non-Atmos-supporting hardware.
Dolby Atmos Height Virtualization, for example, aims to simulate the overhead sound experience of Atmos through speakers at listener-level - i.e. not overhead. Like DTS Virtual:X, it’s designed to create an immersive, 360-degree soundfield from a 5.1, 7.1 or even stereo speaker configuration.
The technology works by applying height cue filters to overhead audio components in a mix before it is dished out to speakers in front of the listener. Dolby says these filters ‘simulate the natural spectral cues imparted by the human ear to sounds arriving from overhead… special care has been taken to equalise the associated filters so that the timbre of the audio remains natural anywhere in the listening environment’.
A number of output configurations are supported. For example, using two to seven listener-level channels to create the sensation of either two or four overhead speakers.
Dolby Atmos content
Plenty of films have now been produced in Dolby Atmos, the first of which was Disney Pixar’s Brave back in 2012. That list has expanded six-hundred-fold (and the rest). Yes, really.
And many have made their way to Ultra HD 4K Blu-ray, too. With all major Hollywood studios now supporting the disc (Disney was the last), the title count is now well into three figures, with the likes of Blade Runner 2049, The Greatest Showman, Alita: Battle Angel, Avengers: Endgame and Shazam! among the latest releases.
There are currently over 40 cinemas in the UK and Ireland that are fitted with Dolby Atmos technology (including the Empire Leicester Square in London) and over 2,700 screens worldwide. You can see a full list of Dolby Atmos cinemas on the Dolby website.
Dolby and Odeon have also opened the first Dolby Cinemas in the UK. The newly named Odeon Luxe Leicester Square was the first. It includes an 800-seat auditorium, which features no fewer than 400 Dolby Atmos speakers and 'spectacular Dolby Vision technology'. Pricing starts at around £10 per ticket, rising to £40 for the best seats in the house.
Aside from the disc, the choice where movies are concerned is fairly limited.
Atmos through the Netflix app is so far supported by certain LG TV ranges, Sony Bravia Android TVs, Apple TV 4K and Microsoft's Xbox One X, Xbox One and Xbox One S games consoles, and Atmos titles include Bird Box, Lost in Space, and Marvel's Jessica Jones.
Amazon Prime Video has featured a small number of Atmos titles, but once again hardware compatibility is pretty limited - this time to Amazon’s Fire TV and Fire TV Stick, Microsoft’s Xbox One, Xbox One S and Xbox X consoles, the Apple TV and LG and Samsung 4K TVs (2017 or newer).
A wider selection of Dolby Atmos content is also now available to owners of a Sky Q 2TB box and relevant subscription package via Sky Cinema and the Sky Store. And Rakuten is another film rental service providing Atmos content - albeit only to certain LG 4K TVs.
Most titles available through Apple TV+, including most Apple originals, support Dolby Atmos. And provided you have the necessary AV gear, Disney Plus streaming service will serve up all of the Star Wars feature films with Dolby Atmos.
The Apple TV 4K also has Atmos support. According to Apple, iTunes is set to become home to ‘the largest collection of Dolby Atmos-supported movies anywhere’.
Away from films, live sports (mostly football) broadcasts are available to subscribers of BT's top-tier Total Entertainment package or Sky Q, and a number of PC and console titles including Gears of War 4, Battlefield 1 and Shadow of the Tomb Raider support Atmos for gaming.
Dolby Atmos on mobile
Dolby Atmos works on tablets like the Amazon Kindle Fire HDX 8.9 (and two Lenovo models) via connected headphones, though it won't be quite as immersive as with a soundbar or surround sound system.
Atmos on a tablet works through 'binaural headphone rendering' and 'object-based audio’. Binaural headphone rendering creates surround sound through headphones via heat-related transfer functions (HRTFs). To explain how this works, Dolby gives an example of a car honking its horn - if it honks to your right, your right ear gets the full blast, while the left ear gets a less intense sound because the sound has to travel around your head. The brain recognises the differences, telling you to look to your right to see if the car is near you.
Dolby has reversed this process to create virtual surround sound from the single speakers in headphones, producing the effect that sound is coming from all around you.
'Object-based audio' is the foundation of Dolby Atmos. Each sound in a scene has information explaining where it should be placed in the speaker configuration, and Dolby claims to have married these two technologies together to create a virtual, enveloping surround-sound experience on a mobile platform.
As for compatible smartphones, the Samsung Galaxy S10+, Galaxy S10 and Note 9 come with Dolby Atmos processing for a wider sound experience, with the likes of the Huawei P20, P20 Pro and P30, Sony Xperia 1 and OnePlus 7 Pro also following suit. We didn't find it all that useful in the Samsung Galaxy S9 Plus, mind you - while it produces a "slightly wider effect", it "slightly blurs and compresses the sound compared to regular playback. We prefer to keep it off most of the time".
Dolby Atmos in music
Not only limited to movie soundtracks, Dolby Atmos also increasingly has music in mind.
Since the first Blu-ray Audio disc with Atmos arrived in late 2015, R.E.M. have released an Atmos mix of their seminal Automatic For The People album (and to good effect, too) and trance artist Matt Darey has specifically written his latest album for the surround technology.
In May 2019, Dolby also announced a partnership with Universal Music Group to bring 'thousands of songs transformed in Dolby Atmos from a diverse list of artists across a wide range of genres, from hip-hop, pop, and rock through jazz and classical music'.
London's Ministry of Sound nightclub has even been kitted out with a 60-speaker, 22-channel Dolby Atmos system. DJs now have the tools to more literally raise the roof - they can make Atmos mixes and edit them in real-time so certain elements of a track move around the room.
Atmos may only be infiltrating the music industry one album at a time, but as our (albeit limited) experience of the matrimony is nothing but positive, we say the more the merrier...
The future of Dolby Atmos
So where else do we want to see Atmos? Virtual reality appears to be a growing area of interest for Dolby. As supported above by the Atmos Height Virtualisation technology, the company is designing tools to deliver Atmos soundtracks in a virtual experience.
There's no doubt the all-encompassing, Atmos- and Vision-supporting Dolby Cinema venture will continue to spread. We'd also like to see Atmos in the car, although Dolby hasn't yet divulged any specific plans to integrate this audio format in the automotive world.
Perhaps the biggest and most immediate area for expansion is more affordable hardware, though. While AVRs - both budget and high-end - are almost all onboard, we'd like a greater choice of affordable speaker solutions and soundbars please. The first wireless speaker to support Dolby Atmos Music is the Amazon Echo Studio but hopefully this is just the first of many.