Fiedler Audio Dolby Atmos Composer

Screen 1: The main view of Dolby Atmos Composer.

Now you can create Atmos mixes using any DAW! But that’s not all this app has to offer...

It probably won’t have escaped your attention that mixing music for Dolby Atmos has become a big deal. Despite the inescapable fact that few music consumers out in the real world are fortunate enough to have listening spaces equipped with, say, 7.1.4 playback systems, there’s a whole load of music being mixed for Atmos. There are several reasons for this. Firstly, the Atmos format is smart: an Atmos mix, which might have been created in a studio equipped with a full‑fat 9.1.6 monitoring system, can, on playback, fold itself down to suit whatever channel format it encounters. Secondly, when an Atmos mix is created, the option is present to render a binaural version for headphone playback — you may have noticed that one or two folk out there primarily consume their music on headphones! Furthermore, Apple Music’s Spatial binaural format is derived from Atmos encoded material, and both Tidal and Amazon offer Atmos binaural music streaming.

Back in the studio world, where Dolby Atmos mixes are created, the workflow has to date required an ‘extended channel width’ capable DAW and Dolby’s not‑inexpensive Dolby Atmos Renderer app. At the time of writing, the only DAW apps that officially support the extended channel widths that the Dolby Atmos Renderer expects are Pro Tools (Studio and Ultimate), Logic Pro, Reaper, Nuendo, Pyramix and DaVinci Resolve. (See the box for an explanation of what I mean by ‘extended channel width’.)

Fiedler Audio’s Dolby Atmos Composer completely upsets the trolley of fruit, because it enables DAW apps that only offer mono or stereo channel widths to join the Atmos party. But there’s much more to Dolby Atmos Composer than that, because along with widening the range of DAW options it offers an Atmos mix workflow and routing philosophy that, to my mind, is better suited to the needs of music mix engineers than the somewhat prescriptive and convoluted demands of Dolby Atmos Renderer. Fiedler’s Dolby Atmos Composer is also pretty affordable.

Dolby Atmos Composer is available from Fiedler Audio in two flavours; the fully featured version and a less expensive Essential version that omits a few of the more advanced features. This review is of the full version. The Fiedler Audio website has a full list of features not included in Essential, but I’ll mention in this review if any feature isn’t included in Essential. While I’m on the subject of software with two versions, closely associated with Dolby Atmos Composer is version 1.5 of Fiedler’s SpaceLab, a multi‑channel/immersive algorithmic reverb plug‑in that’s available in Interstellar and Ignition editions — this is primarily a review of Dolby Atmos Composer, but it’s worth knowing that SpaceLab is fully integrated with it.

Objects & Beds

Before I get on to how Fiedler Dolby Atmos Composer can handle multi‑channel widths in DAWs that can only do stereo, I need to introduce a further complication that Atmos brings to the multi‑channel table: objects. Dolby Atmos is an ‘object oriented’ audio format in that any mono source can be described in terms of its position in 3D space defined by some associated XYZ coordinate metadata. In Atmos‑speak, such an audio source is an ‘object’. Objects can be placed anywhere in the 3D soundfield using a 3D panner plug‑in and they can be dynamically moved around as a mix progresses with as much exuberance as you can imagine. You want that trumpet to circle around above the listener’s head in time to the music? You’ll want to make it an Atmos object.

It’s substantially the concept of objects, with their positional metadata, that enables Atmos mixes to ‘fold down’ to match the abilities of the playback system. The Atmos decoder looks at the metadata and uses clever algorithms to work out how much of that trumpet, for example, should be sent to each available speaker in order for it to appear to be located as close as possible to where the XYZ coordinates say it should be. The more speakers in an Atmos replay (or monitoring) system, the more accurate the subjective result will be. However, Atmos doesn’t simply employ objects, it also allows for audio ‘beds’ (Fiedler Audio use the term ‘composite’ rather than ‘bed’). Beds are the Atmos equivalent of what we used to know as ‘surround sound’ — in other words, audio that’s reproduced across multiple channels to surround the listener and create phantom images. There’s no XYZ positional metadata encoded into beds, so their reproduced location is simply a result of traditional panning (although the panning can also include a height element).

An Atmos mix can contain a mix of beds and objects or be entirely created from one or the other, and the first head‑scratching moments that I suspect occur for any mix engineer on entering the world of Dolby Atmos using Dolby’s own Dolby Atmos Renderer app will concern session routing and how to accommodate beds and objects. It certainly was for me — I have quite possibly never scratched my head quite so much. Where once the paradigm was almost exclusively that a DAW output, bus or bounce is stereo, with the Dolby Atmos...