With the help of this video from Genelec’s Immersive Audio Hub we examine Immersive Audio from the top level. What is it? What is the difference between the formats? What production tools does each involve and what deliverables are created?
Immersive audio introduces a third dimension of sound, typically a height aspect which allows the ‘flat’ ear height only reproduction of surround to envelop the listener. The transition from mono to stereo added width, but only to the front of the listener. Surround formats like 5.1 broadened the soundstage to, as the name suggests, ‘surround’ the listener by adding speakers to the rear but this was still at ear height.
What Is Immersive Audio?
A common element between the various immersive formats is that they allow sounds to be placed above the listener. The details vary between formats but being able to reproduce height allows everything from the dramatic overhead panning of helicopters and the like to a more enveloping reverb experience when listening to recordings of acoustic performances in concert halls
As stated earlier, the details between the different immersive formats varies and one of the most significant differences is between channel based audio and Object based audio. You’ve probably heard about Objects in relation to Dolby Atmos, but Atmos isn’t the only format which uses Objects, in fact, despite the attention it gets online almost to the complete exclusion of the alternatives, while it is the most successful immersive format, Dolby Atmos isn’t the only immersive format which uses objects. This comprehensive video from Genelec’s Eric Horstmann explores the differences and common ground between the most popular formats, both Object and channel based - Dolby Atmos, Auto 3D, MPEG H Audio and Sony 360 Reality Audio.
Isn’t It All About Dolby Atmos?
If you’ve ever wondered, considering the dominance of Dolby Atmos, why these other formats are still relevant then this video is well worth a watch. You might think that the difference is that Auro 3D is channel-based but because the way Objects makes Dolby Atmos capable of being scaled both up and down to suit the number of speakers in a playback system then Auro 3D lacks relevance. In terms of technology and leaving market conditions to one side, that’s not necessarily true. Microphone techniques suitable for capturing Auro 3D recordings exist and high sample rates are supported making it suitable for audiophile use and conventional mastering techniques are easier to implement in channel based formats. And Objects aren’t solely the preserve of Atmos. MPEG H Audio uses objects and has particular relevance for broadcast use.
To find out the differences between these formats check out the section of the video from 2.18.
Looking at the specific implementations of each of these formats, Dolby Atmos in both Cinema and Home applications, Auro 3D and MPEG H, and its cousin Sony 360 Reality Audio, are all discussed in the video, both in terms of their monitoring requirements and the deliverables and different production tools available for each.
Check out the video. This and the rest of the Immersive audio series from Genelec’s G learning Lab are very worth making time for. The video is chapterised and a timestamped list of content is below.
0.00 - Intro
0.54 - What Is Immersive Audio?
2.18 - Formats and Applications - An overview
5.14 - Dolby Atmos In Cinemas
7.08 - Dolby Atmos At Home
8.06 - Auro 3D
9.05 - MPEG H
10.19 - Channel Number Titles Explained (e.g.7.1.4)
11.24 - Channel Based and Object Based Workflows
13.40 - Delivering Content
15.34 - Production Tools