¿What is Immersive Audio?
Immersive Audio is a generalized term for the recording and reproduction of a three - dimensional soundfield. There are several forms of immersive audio (Surround sound formats) being Ambisonics the main focus on several softwares and the industry standard for VR, AR and 360º video.
"Ambisonics is a full-sphere surround sound format, in addition to the horizontal plane, it cover sound sources above and below the listener” (Michael A. Gerzon, Periphony: With-Height Sound Reproduction. Journal of the Audio Engineering Society, 1973, 21(1):2–10.)
In the real world, sound behaves like a sphere (x,y, and z axis). Once we introduce height (z axis) to the equation, a new experience arises, enhancing the emotional level of interaction and perception, one step closer to reality. The main difference between Ambisonics and other multi channel surround sound formats resides in the fact that other formats carry speaker signals in their transmission channels, while Ambisonics contains a speaker independent representation of a sound field (B - Format).
This tool allows the artist to compose in terms of sound source directions instead of arrangement of the speakers, while providing opportunity to decide the amount and layout of speakers (Quadraphonic, Octophonic, Symmetric, Asymmetric, etc).
Many software developers have launched recently several tools that provide access to this technology, such as Dear VR PRO, Envelop for Live, Waves Nx, among others. Each one has its own pros and cons. In this post I would like to showcase a bit of my experience using E4L (Envelop for Live). ¿Why did I choose Envelop? My DAW of choice is Ableton Live 11 so integration / compatibility and versatility (features) is my first priority when looking for a plug-in. On a second degree it is a free open source tool kit. It works really good on Ableton yet there are some tips I would provide at the end of the post. Envelop is a growing community with Immersive Audio spaces in San Francisco, Salt Lake City while providing other formats for Festivals and Outdoor Pop ups. Last but not least, it also allows the user to mix spatial audio in headphones of fully immersive audio for multichannel playback.
Tips worth Sharing:
Bounce everything to Audio, save a copy of your midi project always!
E4L plugins can CPU heavy, I would consider grouping layers that are similar and apply spatialization on the bus group rather than several on individual channels in order to be more CPU friendly. Some people recommend using a separate computer for spatialization, but these tips can make your life a bit easier.
I know we all love LFO and Envelope Followers yet most of E4L plug ins have an in built LFO so you don’t need to overload by adding more to the chain.
RTFM (Read the F**** Manual) Always! Once you do, check the different types of Decoders on the E4L Master Bus, they all sound differently, even for a spatial sound mix (Headphones). **When we talk about immersive audio, we refer to a mix designed for a quadraphonic space onwards (Minimum requirement to provide Immersive Audio) when we talk about Spatial Sound / Binaural, is a mix for headphones.
I’ve been experimenting in a Octophonic Space located at Funkhaus Berlin. I strongly recommend you can work at least with 4 speakers to have a real feel about space as a tool for composition. Think of a speaker as a pixel, the more speakers you have the more accurate to reality you can create - recreate a soundscape / landscape.
This is a Spatial Sound mix using E4L Plug-ins. Enjoy!
