In this set of 4 free video tutorials, Avid Audio Solution Specialist Simon Sherbourne will show how to use the Facebook 360 suite of plug-ins as well as other tools to help you get started creating immersive mixes in Pro Tools Ultimate.
What Is Ambisonics?
Ambisonics is a system for capturing or representing a spherical sound field using regular audio channels. It's the audio format commonly used for Facebook 360 and YouTube 360 videos and VR headsets like the Oculus Rift. It's also very useful for manipulating audio and mixing for any immersive or binaural delivery format.
In this first video, Simon introduces the Facebook Spatial Workstation suite of plug-ins for building, auditioning and mastering an Ambisonics mix that is included with Pro Tools Ultimate. we will look at the tools and plug-ins inside Pro tools Ultimate for working with Ambisonics and VR.
In Pro Tools you can use tracks and busses of 1st, 2nd or 3rd order. In the example in the video Simpon has an Ambisonics 1st order recording captured with a Sennheiser Ambeo microphone. Pro tools Ultimate included the Facebook 360 suite of plug-ins.
This includes the Facebook Spatialise plug-in which is used to position your audio tracks in the Ambisonics sound field.
On the mix track, Simon has the Facebook 360 Control plug-in. This takes the Ambisonics mix and converts it into a binaural headphone feed. It also synchronises with the Facebook video player and captures the video viewing angle so that the audio mix can be rotated to stay in sync.
And finally, Simon has the Facebook 360 meter which measures the loudness of your Ambisonics mix.
In this video, we will look at how to set up an Ambisonics session in Pro Tools Ultimate in order to create a mix for Facebook 360, Youtube or linear VR videos.
First Simon takes a look at the Pro Tools I/O Setup window. He already has a hardware output for headphone monitoring and then he creates a new buss that is 2nd order Ambisonics to be his 360 Ambisonics buss.
Next, he makes some tracks to add to the stereo camera audio already in the session. He creates one 1st order Ambisonics track together with a couple of mono and stereo tracks. He then adds an instance of the Facebook 360 Spatialiser plug-in to each of these tracks to convert their source into 2nd order Ambisonics and then set their outputs to the 360 2nd order Ambisonics buss.
Then he creates a master Fader for the mix, which will be a 2nd order Ambisonics Aux track and names it 360 Mix. He then adds an instance of the Facebook Control plug-in onto the 360 Mix track which will convert the mix to a binaural headphone monitoring feed and sets the output to the headphones hardware output.
The aim is that these new tracks will take care of the sounds that will appear in the 360 degree sound field but you may also want some static sounds like music or a voiceover that don’t rotate when you turn your head around. For those, you need a separate stereo mix and so Simon creates a couple of stereo tracks and routes these to a stereo Aux track called Locked Mix.
In this video, we will look at how to pan or position audio sources within an Ambisonics mix for VR or 360 video.
In his session, Simon has 3 tracks of audio that were recorded at the same time as the 360 video. These need to be panned into the Ambisonics 360 mix to match their positions in the video. All the sources are panned using the Facebook 360 Spatialiser plug-in.
There are 3 different ways to position the sound. There are sliders to adjust the left/right and up/down position, you can use a top-down display to position the source relative to the position of the listener or use the video display to position the sound source directly into a flattened version of the 360 video.
Simon then demonstrates how to use the Audio Ease 360 Radar plug-in to help him accurately position the 1st order Ambisonics track to match the 360 camera position.
In the previous videos, Simon has been using the Facebook Video Client to monitor 360 videos in sync with an Ambisonic audio mix. In this video, Simon shows us how this is set up.
The Facebook 360 Video Client is a separate app that loads and displays 360 video clips. The Video Client links up with the Facebook 360 Control plug-in in Pro Tools, which it detects automatically. The video player lets you move your point of view and hear how this changes your mix in real-time.
Viewing direction is sent to the Control plug-in which rotates the Ambisonics mix and renders a binaural headphone output.
After you open a video in the client, its also shown in the Spatialiser panning plug-ins. When creating audio for a 360 video or VR project it can be helpful to check your mix with a head-mounted display. The Facebook client can be used with the Oculus Rift. However, as the Rift is not compatible with the macOS, you can either use Pro Tools on a Windows machine, like Simon is on the videos, or connect your Mac to a PC.
When Simon switches the client to VR mode and reopens the video he can use the Rift to look around inside his 360 video. At the same time in his headphones, Simon hears a binaural simulation of the sound field in the same directions resulting in a truly immersive experience.