Presenter George Massenburg defines the roles and goals of the oft-undefined term immersive audio.
Engineer and innovator George Massenburg joined the Central Indiana section for a discussion of immersive audio mixing, highlighting his recent experience with remixing major popular music artists in Dolby Atmos, as well as his experience with current and upcoming consumer delivery methods for immersive content.
George began the presentation with a brief history and overview of immersive audio, stretching back to stereo and early surround. The early use of binaural transmission in the 1881 Paris Opera telephone transmission was highlighted as a truly early form of immersive audio, despite being often overlooked. Further developments presented ranged from Alan Blumlein's stereo innovations, quadraphonic recordings, Todd-AO surround, Dolby Stereo, DTS Surround, and other such formats. DTS Music Disc, DVD-Audio, and SACD were also highlighted as previous music-specific immersive formats. George was careful to highlight not only the success and innovations of many of these technologies and formats, but also to acknowledge some of the commercial shortcomings of earlier forays into immersive music.
Following the historical context of immersive audio, George moved into the realm of Dolby Atmos. Discussion began with the basic components of an Atmos mix: bed tracks and objects. George discussed the use of 7.1.2 (7.1 with two height channels) and 7.1.4 (7.1 with four height channels) channel-based bed tracks as the foundation for a mix, with the remaining 110+ reserved for objects that can be placed and manipulated outside of these defined speaker locations. George carefully defined the sometimes-nebulous term "object" in reference to Atmos, including their encoding in mixing and decoding during playback. George also provided a glimpse into his signal flow/studio setup for immersive mixing, with dedicated playback/mixing and capture/render computers and multiple monitoring formats and devices, including both professional monitor loudspeakers and consumer devices for immersive playback.
George then ask for questions from viewers online, received in via YouTube chat, text, etc. This garnered an incredible range of immersive audio sub-topics, including the differences between mixing/re-mixing for immersive rather than capturing immersive content from the recording stage. The difficulties in re-mixing content that exists in an artist-approved stereo iteration was also discussed. George was careful to note that one of the first steps to an immersive remix is often to recreate the existing stereo mix, then branching out from the sounds, feelings, and intentions existing in that format. Questions regarding consumer delivery were also addressed, with topics such as single-point immersive systems (e.g. sound bars, wireless home devices, etc.), binaural renderings, MPEG-H encoding, and mobile audio all discussed.
George both started and ended the evening on an uplifting note, emphasizing the fact that immersive audio opens up a world of opportunities for increased artistry. Our goals as immersive content creators should be to provide a truly special and authentic experience for artists and listeners alike.
