Everything you need to know about the leading spatial audio format
If you’ve been on the hunt for a new TV, soundbar, speaker or even a new pair of headphones then you’ve probably come across the term “Dolby Atmos”.
It’s become a buzzword for immersive audio, and is seemingly now plastered on everything from soundbars to smartphones, to streaming sticks and services, and even in cars.
But what exactly is Dolby Atmos, and why do you need it in your life?
After all, there seems to be a new Dolby audio format every other week, so it’d be easy to chuck Atmos onto the pile with the likes of Pro-Logic and Digital Plus… i.e. formats you couldn’t care less about.
However, Dolby Digital, and the whole spatial audio revolution, is a big deal. Think of it as the audio equivalent of going from black and white TV to color.
Guide: What is spatial audio
It’s a significant leap forward in how you’ll experience sound, with a three-dimensional soundscape that surrounds you, making you feel like you’re truly in the action.
It’s more than just improved clarity; it’s about experiencing sound as the creators intended, with unparalleled space and depth.
It works for music, movies, games and more – read on to learn everything you need to know about Dolby Atmos.
Beyond stereo
Traditional stereo sound, which has been the standard for decades, splits audio into two channels: left and right. Surround sound, like 5.1 or 7.1 systems, added more speakers to the mix, creating a more enveloping experience.
In a real-world example, you might have a Sonos Ray counting for 3 of a 5.1 system – front, left and center – with two Sonos Era 100s at the rear making up the 5, with a Sub adding the all important .1.
But spatial audio formats like Dolby Atmos take things further. It’s not just about adding more speakers; it’s about changing the way sound is mixed and delivered.
It uses something called “object-based audio.” Instead of assigning sounds to specific speaker channels, each sound – an actor’s voice, a raindrop, an explosion – is treated as an independent audio object. These audio objects can then be precisely placed and moved within a 3D sonic space.
Imagine a scene in a movie where it’s raining. With traditional surround sound, the sound of rain might be assigned to the left and right speakers, making it sound like the rain is just coming from the sides.
With Dolby Atmos, each raindrop is treated as an individual audio object (well, almost), allowing sound designers to place them with pinpoint accuracy, creating a realistic and immersive downpour that seems to come from all around you, even from above.
Dolby Atmos uses up to 128 audio channels, with 10 dedicated to ambient sounds and the rest for these precisely placed audio objects, creating a dynamic and all-encompassing soundscape.
How does it work?
For your home theater setup, Dolby Atmos is typically experienced through soundbars or multi-speaker systems, although you can actually get TVs with their own Atmos speakers built in.
Whether you have physical speakers placed around the room, or rely on a soundbar with Atmos smarts, they will use a combination of traditional and upward-firing drivers to create the illusion of sound coming from all directions.
Those upward-firing speakers are key. They bounce sound off your ceiling, effectively creating a height dimension to the mix. This allows for realistic reproduction of sounds that originate from above – think rain falling, a plane flying overhead, or the ambience of a rainforest.
Soundbars like the Sonos Beam (Gen 2) or the Denon DHT-S517 use these upward-firing drivers to deliver height effects, though some use digital signal processing to create a virtual Atmos effect.
More elaborate setups, like a 7.1.4 system (seven speakers at ear level, one subwoofer, and four overhead speakers), can provide an even more immersive experience. While you can go up to 34 speakers at home, Dolby recommends aiming for around 12 for the best experience.
Take that Sonos 5.1 surround sound setup we mentioned earlier. If you swap that Ray out for the likes of a Sonos Arc or a Beam 2, throw some Era 300s at the rear – all of which boast Dolby Atmos – and you’ve now got yourself a 7.1.4 system, which means 7 at ear level now, not 5, 4 overhead speakers, and the .1 for the sub remains.
But it’s not all about sounds from above. Dolby Atmos also creates a wider and more enveloping soundstage using side-firing speakers.
These bounce sound off your walls, making it seem like the speakers are placed further apart than they actually are.
Some soundbars even use clever digital signal processing to create virtual rear surround speakers, which is handy if you can’t, or won’t, run cables around your living room.
In fact, the Sonos Arc Ultra claims to do 9.1.4 Dolby Atmos spatial audio sound all on its own.
Dolby Atmos for headphones
Dolby Atmos isn’t just for your home cinema setup though; it’s also available for headphones, offering a personalized spatial audio experience.
Instead of relying on physical speakers, headphone-based Dolby Atmos – which is used for Apple’s Spatial Audio tech on the likes of the AirPods Max – uses binaural rendering and Head-Related Transfer Functions (HRTFs) to simulate how sound naturally travels to your ears in a 3D space.
This tricks your brain into thinking the sound is coming from outside your head. This can be achieved through software or hardware integration on mobile devices, with some devices using accelerometers for head-tracking.
Head-tracking technology, found in some high-end headphones like the AirPods Max or the Sonos Ace, add another layer of realism. They track your head movements and dynamically adjust the audio in real-time, creating a more believable and engaging experience, especially for things like blockbuster movies and games.
Dolby Atmos music
Dolby Atmos has also made its way into the music industry, with many of the latest tracks now mixed with spatial audio in mind – check out Clash by Dave and Stormzy if you want your mind blown.
Older albums, such as the Beatles’ back catalog and the likes of REM, Neil Young and Pink Floyd, are also now being remastered for the new format too.
Dolby Atmos Music allows artists and producers to place instruments and vocals with incredible precision, offering a more immersive and engaging listening experience.
You can find Dolby Atmos Music on streaming services like Apple Music, Amazon Music Unlimited, and Tidal.
Why is Dolby Atmos so popular?
Dolby Atmos has become the dominant force in spatial audio for a few key reasons. The biggest driver is that it’s supported by not only a huge range of devices, as we’ve mentioned, but also all of the major streaming services too – think Netflix, Disney+, Apple TV+ and the like.
Add to that the latest top-end smartphones, tablets, laptops and games consoles also often support Atmos, and you’ll often find the latest TV shows and live sporting events available with Atmos audio through cable boxes, set top boxes and more too.
You also won’t need to buy a new Blu-ray player as standard Blu-rays are capable of containing the necessary Dolby Atmos data, as are Ultra HD Blu-rays.
Dolby Atmos really is a seismic shift for audio but its effectiveness does depend on the setup. While cinemas and full home theatre systems with real physical speakers placed strategically around the room provide the best results (Dolby has a load of guides on how to do this), Atmos soundbars and headphones still offer a pretty dramatic upgrade over standard stereo or surround sound.
If you’re relying on a budget-friendly soundbar or built-in TV speakers, you might not get the full effect, although it will definitely be an improvement still.
Dolby Atmos isn’t the only spatial audio format though, the likes of DTS and Sony have some pretty nifty tricks up their sleeves too, so be sure to read our guide to spatial audio to learn more.
