What is DOLBY ATMOS?

Dolby Atmos uses metadata in addition to traditional audio to create an immersive experience for listeners. What this means is that sound is no longer bound to a set amount of speakers in a monitoring environment and is panned using coordinates in 3D space rather than by channel. It also adds the dimension of height to the existing surround plane so that the project really can exist in a 3-dimensional way. When mixing, we are able to position elements within your creative project all around the room in any direction; from side to side, front to back as well as above you. Because of the metadata, the information is mapped using software rather than traditionally straight routing and can be extrapolated into a scalable system. This is how Dolby Atmos is able to offer playback to a wide variety of sound systems and layouts of many different arrangements and speaker amounts. This offers the ultimate experience for your listeners no matter what device or environment they are playing it in, from a phone, a 5.1 home theatre system or a 80 speaker theatre.

Channel-based Audio First there was mono, a single speaker. Sound could only come from a single place and was entirely 1 dimensional. When stereo was introduced, it gave you 2 speakers (left & right) which changed the game in a big way and is still used as an effective standard for delivering music. Adding to that, rear speakers were added which was called quadrophonic, encompassing listeners in a pair of front stereo channels and rear stereo channels. When 5.1 came about, the industry changed again. It allowed for a centre channel for clear vocal and dialogue while music and effects could be panned in a 5 speaker array. The .1 described a dedicated sub-woofer channel that allowed for a full frequency response within a 6-channel mix. Next came 7.1 which added sides the the existing array of channels and delivered a more detailed sonic experience particularly in the areas where audio would move from front to back or vice versa, side speakers would make the transition seem that much more realistic. The only problem was the for each of these systems, the delivery was only ever a single tiered option and the consumer would have to ensure they were playing the optimised version for their speaker system. This meant that filmmakers and musicians would have to create multiple mixes for each delivery format to allow each tier of speaker system have a playback option. It was expensive and tiring especially for audio engineers and creatives. Object-based Audio Now enter Dolby Atmos. A new way to mix using computing technology that had never before been used to create music or soundtracks for film. Instead of creating multiple mix deliveries for specific speaker layouts, Dolby Atmos lets us create one mix that encompasses all of them in the best way. We used to pan audio to a fixed speaker location to create surround sound fields or even stereo mixes with width and dimensionality. With Atmos, we use coordinate based objects that retain metadata to allow for upscaling or downscaling the ratios in which they make up a mix. This means that on any speaker system setup for any format, Atmos can play material to suit. But that's not all... It also added a new dimension - height! In addition to scalability, saving multiple mixes and simply building a one mix fits all scenario, we now can pan audio as objects above the listener to improve the immersion even further. Now sound exists in all directions surrounding you like never before. We're still not done... Dolby Atmos's metadata speaks to the playback device - which now are occupied by iPhones, cars, TVs, sound systems, cinemas... giving you the best possible output for whatever destination you send it to. There is even a binaural version that emulates surround sound for headphones to make it feel like you have speakers all around you. Dolby Atmos is the smartest choice when building you creative project's audio mix because it gives your audience the broadest scope and flexibility when listening to provide the best possible experience wherever they are. Dolby Atmos is here to stay!

Because Dolby Atmos uses metadata to pan with coordinates in three-dimensional space, the system is scalable both up and down to any speaker layout. This means that when you mix your project in Dolby Atmos, it also includes a superior way of down-mixing from Atmos to other channel-based surround formats that are still widely used. These include: 7.1 Surround 5.1 Surround Stereo AmbiX Binaural

Mixing your project in Dolby Atmos requires a few things. We’ll need the following: Tempo/BPM information Quantity of mix stems Stereo final Master reference (if released) Audio files at unity Mix Stems at 48kHz 24bit No mix bus or group processing When applicable, provide a AAF file including all audio files

The Dolby Atmos delivery package is known as a Master File. There are four types of Atmos Master Files. The first is a DAMF DAMF (Dolby Atmos Master File) filename.atmos filename.atmos.metadata filename.atmos.audio ADM BWF (Audio Descriptive Model Broadcast WAV Format) This file is an alternative to DAMF and is not proprietary to Dolby. It is a single file that is basically a broadcast WAV with a huge data chunk at the head containing the .atmos and .atmos.metadata information. IAB/IMF (Immersive Audio Bitstream for IMF) This is a frame based representation of the DAMF in a single file, which is specified for IMF (Interoperability Mastering Format). IMF mastering tools can be import and export IAB/MXF and master to IMF. IAB/IMF is an .mxf file with interleaved PCM and metadata. 9.1.6/7.1.4/5.1.4 PCM The Dolby Atmos Mastering Suite and standalone Dolby Atmos Production Suite can render to 9.1.6, 7.1.4, 5.1.4. Rendering Object Based Immersive (OBI) to Channel Based Immersive (CBI) is a hybrid workflow. OBI is used during the creative process and CBI for encoding and delivery. The 9.1.6 is rendered by the OAR in the consumers home and with speaker layouts at 9.1.6 and below is identical in listening tests to the rendered OBI. While not technically delivering “real” OBI the use of 9.1.6 can simplify downstream workflows for editing, joining idents and ratings card, watermarking, etc. 7.1.4 output is provided to allow for immersive cut scenes and trailers in gaming engines to accompany realtime game play. 5.1.4 is provided to facilitate immersive post produced sound design for live playout CBI applications.

Dolby Atmos is available across the world on a huge variety of platforms. For film & tv, all major distributors have adapted the format to offer the best sound options including Disney+, Netflix, Amazon Prime & Stan. In addition to streaming services, BluRays are capable of encoding Dolby Atmos for home entertainment as well as DCP's for cinema play can be created for filmmakers. Once built, the delivery can offer playback in any Atmos enabled theatre no matter the speaker format as a result of the metadata encoded.

Apple has adopted Spatial Music as a Dolby Atmos distributor while others like AvidPlay, Tidal and Amazon Music have also been offering atmos players for the last few years. In addition, Spotify is well on the way to adding Dolby Atmos to their list of services and will complete the circle for all of the major players in the music industry.

If you have already partially mixed a track in Dolby Atmos and are looking to finish it with Stampede Immersive, we ask you to provide us with the following things to get started. Current ADM for reference Current IMF Original Stereo reference Current Stereo reference DAW Session if applicable Original multitrack