In this series of 6 articles, Post-Production Specialist and Immersive Audio expert Alan Sallabank will be sharing tips and tricks to help you get to grips with the audio post-production workflows for content to be delivered in Dolby Atmos Home Entertainment, which will be especially useful if you are delivering to the likes of Netflix and Amazon. Multi-national and streaming distributors are especially keen on Dolby Atmos, as it is what is known as a “single file delivery”, which automatically adapts according to the playback device.

What You Will Need

The Dolby Atmos Production Suite and The Dolby Audio Bridge are software solutions, so while you don’t need any specific Avid or Dolby hardware to follow the advice in these tutorials, you will need specific versions of software -

• Pro Tools Ultimate 2019.10 or later - 2020.5 recommended

• Dolby Atmos Production Suite v3.4

Running everything in software does also put quite a strain on your host computer, so I would also recommend that you are running a machine with at least six physical cores and at least 32GB of RAM.

Consider Watching Parts 1 Through 4 Before You Go On

If you are new to Dolby Atmos we strongly recommend that you watch and read parts 1 through 4 of this series before continuing with part 5.

Part 5

In this free video tutorial, brought to you with the support of Avid, looking at Dolby Atmos Home Entertainment workflows, Alan looks at best practice when using immersive upmixing and reverb plug-ins, with a firm focus on ensuring downmix compatibility.

The First Rule Of Surround Sound

Why do I bother using objects for height channels instead of the 7.1.2 beds available within Pro Tools? The answer to this comes straight back to the First Rule Of Surround Sound, which is:

“Never send exactly the same signal to both the front and rear.”

Unfortunately, the bed infrastructure within Pro Tools only allows for one stereo pair of overhead channels. The upshot of this is that when you send a stereo height channel to the Dolby Renderer, it gets fed equally to both the front and rear height pairs (of a 7.1.4 monitoring setup), and most importantly, gets fed equally to front and rear in the resulting fold-down.

What’s Wrong With Sending The Same Audio From All Speakers?

Think about it - in real life, this never happens. When it is “forced” upon us, it sounds un-natural and adds to a “pressure cooker” effect, making your mix more fatiguing to listen to. When it comes to folding down that immersive mix to a “flat format” or even stereo, this can cause a whole manner of issues, including legibility issues and matrix cancellation.

We will be looking at four of the most capable and popular plug-ins available at present:

Nugen Audio Halo Upmix 3D

Nugen say:

“From naturally extracted and expanded soundscapes to full cinematic big-stage enhancement, Halo Upmix delivers all the control you need to fine-tune your surround mix to perfection. With unique centre channel management, including switchable dialog extraction, Halo Upmix is perfect for all types of production from archive restoration and TV through to the full 7.1 feature film experience.

An optional 3D extension adds Dolby Atmos bed track (7.1.2) and Auro 3D (7.1.4) compatibility, and Ambisonic outputs.

The Halo Upmix algorithms produce a natural, coherent spatial upmix, preserving the character of the original audio without adding any artificial reverb, chorus or delays.

With the 'Exact' control engaged, Halo Upmix can be used with confidence that the original source integrity is precisely preserved in the downmix.”

PerfectSurround Penteo 16 Pro

PerfectSurround say:

“The all-new Penteo 16 Pro includes six products in one unified plugin that handles every Stereo, 5.1 / 7.1 Surround or 3D Immersive upmix or downmix scenario. Post-production sound designers, re-recording mixers, sound designers, composers and educators rely on Penteo to deliver an immediate, high quality, phaseless upmix from Stereo film, broadcast, streaming, VR /AR and education.”

iZotope (Exponential Audio) Stratus 3D / Symphony 3D

iZotope say:

“This plug-in can handle up to 22 channels of immersive reverb. Surround and 3D audio aside; Stratus is a fantastic sounding algorithmic reverb that works on every kind of source material. The precise control over the early reflections and reverb tail separately provides all the parameters you need to place a signal in any space or ambience.”

Liquidsonics Cinematic Rooms Pro

Liquidsonics say:

“Cinematic Rooms is a reverb dedicated to the intense acoustic demands of surround room simulation. Deep yet accessible; advanced surround workflow tools allow you to design intricate acoustic spaces of incredible purity with simplicity. Available in two editions, both support channel formats from stereo up to 7.1.6 for use with the latest Atmos bed workflows.”

Free Tutorial

In this episode of the Pro Tools Expert free Dolby Atmos tutorial series, we explore the different ways that different plug-ins facilitate being able to output to a higher channel count than the default 7.1.2 format available in Pro Tools:

Next Episode

Come back for the last episode of this free tutorial series, where we’ll be looking at possibly the most important aspect of Dolby Atmos Home Entertainment workflows, the end game - Mastering.