How to assemble a Dolby Atmos mix

Adam Daniel, a re-recording mixer based at Point1Post in Elstree, UK, provides his tips on working with the much talked about technology.

It has been eight months since we completed our upgrade to Dolby Atmos at Point1Post. I wanted to share some of the approaches we use to create Atmos mixes and to discuss how the system enhances the viewing experience.

We use three main approaches when creating Atmos mixes. These are mixing from existing stems, premixing in Atmos, and a hybrid where we use a combination of existing stems and original source elements. The amount of available time and access to sound elements dictate which method we use.

The most limited approach is to use existing 5.1 stems as source material. The stems usually consist of dialogue, music and FX (separate BG’s, hard FX, sound design and Foley).

The ability to choose which elements remain in the traditional channel-based beds and those that can be turned into audio objects is vital. This method is most commonly used on shorter form projects such as trailers and commercials.

More complicated projects require greater flexibility. It is quite common for us to host Dolby Atmos mixes for films that have already been mixed in other studios – the original mixers and sound supervisor often attend these. We use a combination of existing stems and original source sessions, and we like to recreate outboard setups if possible. Having access to original automation really helps. With so much premixing occurring within Pro Tools this is usually a very simple process. If extensive automation has been used on a large-format console for the FX then I would advise using a similarly equipped Atmos studio.

In my experience it is less of an issue to transfer dialogue and music because the pre-dubs or stems are often easier to adapt to Dolby Atmos than the FX. Using this hybrid approach you can carry the original stems but swap back to the original source sessions for areas that will benefit from the additional features of Atmos.

Our preferred approach is to premix in Atmos and have control of every element. Native Atmos mixes are now becoming more commonplace. Sadly, not every production has the luxury of both premixing and final mixing on an Atmos stage.

Dolby realises that modern workflows often involve setting up and preparing mix sessions in smaller mix rooms or edit suites. For this purpose, the company has created the Local Renderer. The plug-in allows you to use Atmos tools but without the Rendering and Mastering Unit hardware. It is a software solution for monitoring Atmos content using Pro Tools, and supports up to 16 audio outputs. In its most common configuration you can mix using the Atmos tools, but monitor the Sound Objects and 9.1 Bed in 7.1/5.1. When you arrive on the Atmos stage you simply open it up and it’s like lifting a blanket – all of the preparation and mix decisions are revealed. You already know that it works in 7.1/5.1 and now you are adjusting to taste rather than starting from scratch. It is a really neat and efficient way of working.

Enhanced experience

Working in Atmos has made me appreciate how much it enhances the viewing experience. The surround speakers are now full frequency range and calibrated to the same level as the screen speakers, while bass management helps to ensure that the timbre of the sound is maintained throughout the room. This makes a huge difference and creates a fuller sound.

The ability to individually feed the speakers means that you can position sound objects with incredible accuracy. The Dolby Atmos Panner allows you to follow the trajectory of elements in the x, y and z axes. It sounds so natural because you are not panning into an array and the elements have the same weight off screen.

I love using the 2.0 stereo overhead bed for BG atmospheres. In recent mixes I have used sends to fill the ceiling with airs and winds. Creating a contrast between the ceiling and walls is very effective at building a natural and immersive feel. It is also handy for more specific sounds like rain on a tin roof.

The rest of the 9.1 bed is a conventional 7.1. If there is any chance that your project is going to have an Atmos version then I would thoroughly recommend that you complete your tracklay and any mixing in 7.1. This isn’t to say that you need a 7.1 setup. You can simply down mix your output back to a 5.1. However, if the internal mix busses are 7.1 then you will save a lot of time when you arrive on the Atmos stage. So far every project we have mixed from other studios has been delivered in 5.1. It has always been a non-creative and time-consuming process to up mix the 5.1 to 7.1. Any panning that you do in 7.1 will create a far more interesting bed that complements Atmos.

Atmos is the most significant advance in film sound that I have experienced; it feels like I’m just scratching the surface. I’m so excited that more and more of our clients are choosing to work in this format.