AMBEO for Video Games is a flexible solution for the recording and creation of immersive audio ambiences. Recording complex ambient environments is made easy through the use of the Sennheiser AMBEO VR Mic, which allows for creators to capture the true sound of a location using a single microphone. By using recordings from a Sennheiser AMBEO VR Mic as a base and adding other sound effects and signals from spot microphones, game sound designers can create complex and flexible background beds for console, computer and VR/AR video games while using less computational resources then individually rendered spot sources. The techniques described below work best for things like music, ambient sound, and other background sounds that a player wouldn’t interact with in a game.
A single compact microphone operating on the Ambisonics principle, it allows you to capture complete spherical audio from a single point in space. Basically, you capture exactly what a listener would hear if he or she was in that position. This technique allows you to capture hard to recreate soundscapes, such as the interior of a race car or any other particular acoustic environments.
It sounds easy but some care should be taken to record the Ambisonics signal correctly with regard to position and level, as certain errors cannot be corrected during post-production. A field recorder that has an AMBEO VR Mic mode will help to make this task far easier.
On location, the AMBEO VR Mic will usually be combined with conventional microphones such as wireless lavalier mics. This allows for increased flexibility during post-production, giving the mixing engineer greater control over the ambient mix.
DAW and tool chain
Mixing your ambisonics bed can be done in most standard DAWs as long as they support multichannel tracks, i.e. a minimum of four channels in a track. To support you in the mixing process, you should select an Ambisonics tool chain. There are many tools to choose from, such as DearReality’s dearVR tool chain or the free Spatial Audio Workstation available from Facebook.
Recommended mixing paradigm
Use the recorded Ambisonics signal as the base ambience, then add signals from conventional microphones such as wireless mics and foley sound to emphasize and build your final ambient bed.
As all Ambisonics tool chains operate in B-format, you first need to convert the AMBEO VR Mic signal to B-format using the dearVR AMBI MICRO .
Additional sound sources captured by conventional microphones need to be spatialized so that they sound as if they come from your intended point in space and match the recorded ambience. This step is accomplished by your selected Ambisonics tool chain.
During mixing, it is important to monitor your Ambisonics mix. However, before you are able to listen to it, Ambisonics must be decoded. This step will depend on whether you plan to deploy to console, computer game or into a VR/AR game. In the case of deploying to a VR/AR game, please decode your mix using a binaural renderer (the best practice is to use the renderer that will eventually be integrated into your final game). For deployment to a traditional game in either stereo or 5.1, the ambisonics signal must be decoded to loudspeakers. We recommend HARPEX X, a partner of Sennheiser, to decode the signals to various loudspeaker arrangements.
A note on working with Ambisonics
Ambisonics is the description of a sound field. Therefore, you should never work on any of the constituent tracks of an ambisonics signal on its own. Always use Ambisonics mixing and editing tools if you want to modify an Ambisonics signal. When using a standard multichannel mixing tool, you must make sure that changes are applied equally to all four channels – otherwise you risk altering the spatial image of the Ambisonics signal.
Console and Computer Games
Ambisonics is a versatile format that can be decoded to suit different playback environments from mono to 5.1, 7.1, or any other arbitrary speaker arrangement. Some plugins exist for game engines that allow for loudspeaker decoding directly in your app, but you can be equally served by pre-rendering your ambisonics mix into 5.1 or whatever speaker arrangement you’d like to deliver. We recommend processing your signal using HARPEX X. Once the signal has been decoded, bring it into your middleware or game engine as you would any surround sound audio file.
Most game audio middleware and game engines natively support ambisonics to binaural decoding. Please see the documentation of the game audio tools you expect to use to see what formats they support and how their ambisonics support works. As all of the sound sources in your ambient bed is “pre-baked” into the ambisonics signal, you can save significant computational resources by rendering a single ambisonics bed instead of having many individually rendered sound sources.