Apple’s spatial audio technology is about to get a lot bigger. Introduced as a major AirPods Pro upgrade and later included on the AirPods Max, pretty much entirely to upgrade video playback, spatial audio is now coming to Apple Music as well.
But what is spatial audio, and how do you use it? In this guide we’ll explain everything, from what hardware you’ll need for spatial audio to how to get this interesting 360-degree sound feature up and running.
What is spatial audio?
Spatial audio is how Apple brands its immersive, 360-degree sound tech, though the concept is sometimes referred to as “spatial audio” in more general terms as well. It’s essentially a form of surround sound wherein the origin points of different sounds stay in place even as you move around.
That sounds like plain, old, living room surround sound, right? Except spatial audio can keep those origin points in place even when the speakers themselves are moving, namely on headphones like the AirPods Pro and AirPods Max.
Say you’re watching a film on your iPhone where someone is loudly walking along the left of the screen. If the movie is compatible with spatial audio, you could turn your head to the left and the footsteps would then sound like they were coming from straight in front of you.
Being a form of 360-degree audio, spatial audio’s effect isn’t limited to a flat axis either. Like Dolby Atmos or DTS:X, spatial audio can add a sense of height, making TV and movie playback even more immersive. In fact, Atmos-mastered content can be played as spatial audio content, provided you have the right headphones.
How do I use spatial audio?
The most important thing is making sure you have the right hardware. Right now, the only spatial audio-compatible audio devices are the AirPods Pro and AirPods Max, so pick up one of those unless you want to wait for the rumored AirPods Pro 2. The AirPods Pro didn’t launch with spatial audio support, but it should download and install the required firmware automatically.
However, when Apple Music launches spatial audio support in June 2021, any Apple or Beats headphones with a W1 or H1 chip will be compatible. That includes the standard Apple AirPods, Beats Powerbeats 4 and the Powerbeats Pro, among others.
Next you’ll need a compatible source device, namely an iPhone or iPad running iOS 14.3 or later. However, not all older Apple devices will work, even if they can be updated to the requisite version. Here’s a list of spatial audio-compatible devices:
- iPhone 7 or later
- iPad (6th Gen) or later
- iPad Air (3rd Gen)
- iPad mini (5th Gen)
- iPad Pro 12.9 inch (3rd Gen) or later
- iPad Pro 11 inch (1st gen) or later
Apple also says that Apple Music’s spatial audio content will be playable through the speakers of the “latest versions of iPhone, iPad, and Mac,” though we’d be surprised if the effect was nearly as strong as if you were wearing headphones.
With compatible hardware you’re almost set, and remember that you can turn spatial audio on or off at your choosing. To turn if off while you’re already watching a video, open the Control Center, press and hold the volume control then tap on the spatial audio option to disable it.
To turn spatial audio on or off for everything, open Settings and navigate to the Bluetooth menu. In the list of connected devices, tap the “i” icon next you’re your AirPods then select whether to turn spatial audio on or off.
Also important to note is that media content must be available in the 5.1, 7.1 or Dolby Atmos surround sound formats for it to work with spatial audio. At the time of writing, spatial audio is only available for video content, though Apple Music is bringing “thousands” of Atmos-mastered songs in June.
Some music streaming services already provide Dolby Atmos-compatible songs, namely Amazon Music HD and Tidal. Still, Amazon limits Atmos playback to its own Echo speakers and Tidal seems to be keeping its immersive capabilities exclusive to Sony’s Spatial Audio rival, 360 Reality Audio. As such you can’t get spatial audio music from either, leaving Apple Music as the sole source of compatible tunes.
How does spatial audio work?
There’s a few things that are needed to make spatial audio happen. First, sound engineers will map the individual audio parts of a piece of content — dialogue, sound effects, non-diagetic music and so on — to specific points on a digital 3D space. Imagine a sphere build around the listener, with each sound source placed around it. This allows for those individual sounds to seemingly come from either side, behind, above or below you. Engineers can also adjust the “distance” of sounds so that they seem closer or further away.
Obviously, headphones don’t have a series of satellite speakers for “true” surround sound, and they can’t achieve a sense of height by bouncing sound off ceilings like Dolby Atmos does. So spatial audio’s surround sound effect needs to be purely digital.
Here’s where it gets a little complicated. 360-degree audio playback on headphones is achieved though Head Related Transfer Function (HRTF) filters, which digitally adjust how sounds are played so that they bounce into your ears in such a way that they appear to originate from a certain direction. It requires both ears for your brain to perceive the intended effect, which is why the technique is known as “binaural rendering.”
The extremely basic version is that your brain is tricked into thinking you’re receiving sound from a fully three-dimensional space even when it’s coming from a set of two drivers either side of your head.
Once the matter of fitting surround sound into a pair of headphones is settled, spatial audio can then use head-tracking to create that feeling of being able to love around (or at least look around) the 3D space. The AirPods Pro and AirPods Max therefore contain accelerometers and gyroscopes, which can track your head movements in relation to an anchor device: the phone or tablet that the headphones are paired to.
Because the anchor device contains the screen on which you’re watching the spatial audio-mastered content, the system can make sure that sounds are played from directions consistent with the on-screen action. All while you can move your head around inside that 3D space.
However, we expect Apple Music’s implementation of spatial audio will be a bit simpler. Because the content is pure audio, it makes less sense to use the source device as an anchor point, and more importantly most H1- and W1-equipped headphones don’t have gyroscopes and accelerometers for head tracking. As such, it will probably be more akin to Sony’s 360 Reality Audio: there will still be a 3D effect, with instruments and vocals surrounding you, just without the origin points of sounds staying in place as you move your head.