Re-recording Near-field Mixes for Dolby Atmos Blu-rays

Posted Mon Nov 24, 2014 at 08:05 AM PST by

Dolby was kind enough to invite HDD to its Burbank Laboratory for an in-person demonstration given by Atmos re-recording sound mixer, Tim Hoogenakker, and to watch 'The Expendables 3' on Blu-ray in their Home Theatre room. Full disclosure: in addition to excellent audio, I was plied with hefeweizen and pizza, and, therefore, have subsequently started burning all of my DTS-encoded Blu-rays and will now say pretty much anything Dolby wants.[1]

You can read my full thoughts over at 'The Expendables 3' Blu-ray review, so let's get into the Dolby Atmos Blu-ray re-recording process.

Inside Dolby's Burbank Lab, The Atmos Project Studio is a smallish mixing room where all the current Atmos Blu-rays have been re-recorded -- Paramount and Lionsgate titles including 'Transformers: Age of Extinction', 'Step Up All In', 'The Expendables 3', and the upcoming 'Teenage Mutant Ninja Turtles'.[2] Other titles have been mixed here too, though they can't yet say which ones. Warners too is excited about Atmos -- with the already announced 'Gravity' Diamond Luxe Edition hitting stores in February -- and has their own on-lot studio room.

In addition to ProTools gear, Dolby's Atmos Project Room features a 9.1.4 configuration -- left, center, right, two pairs of side surrounds, two rear surrounds, and four overhead speakers -- but all of the Atmos mixes thus far have been mixed in 7.1.4 (only one pair of side surrounds running). Genelec 1037B active studio speakers (they cost almost $6,000 each!) handle left, center, and right channels. Niles DS8HD in-walls (and in-ceilings), driven by Crown Drivecore 300N amps, service all surrounds. Two Ken Kreisel subs (which Dolby "LOVES") -- one for mains bass management and LFE, and one for the surrounds -- pump out the low end.

First new fun fact learned: in the absence of an Atmos AVR, all Dolby Atmos Blu-rays fold down to 7.1 TrueHD even if the film was originally mixed in 5.1 like 'Step Up All In'. They're also capable of folding down to 5.1 or 2.0, of course, but there aren't going to be any Atmos titles that fold down to 5.1 on a 7.1 system unless the studio provides a separate 5.1 option. That should also mean, for example, the new 'Gravity' Blu-ray will be an audio upgrade regardless of whether or not you have already adopted Atmos. Cool.

We first met re-recording mixer Tim Hoogenakker a few years ago when he was up-mixing 5.1 theatrical mixes to 7.1 Blu-rays for clients like Lionsgate. When Tim sets out to do what's called a Near-field Mix, he typically receives the film's theatrical Atmos sound mix in the form of a ProTools session. Inside this file, Tim will find the 5.1 or 7.1 channel bed that includes dialog, music, and sound effects PLUS hundreds of individual sound objects that have been positioned using a special Dolby Atmos controller like this:

Dolby Atmos Pro Tools Session
Pardon my iPhone Photography. Sigh.

This blurry image was taken as we played the Dolby "Unfold" Atmos trailer (embedded below). The left monitor houses all of the tracks. Eight of those handle that 7.1 bed, with the others are individual objects. On the right monitor, you'll see two windows. The left window is a map of a 7.1.4 Atmos configuration as seen from above. When mapping an object to the soundscape, re-recording mixers like Tim are able to position individual effects and music stems to specific channels or the space between channels, and add height. In this window, the yellow dots are smallest at ear level, and become larger when you pull object up to height channels. 

The right window (on the right monitor) is a 3D map of all the individual objects moving through space in real time. Since this is a Dolby Atmos demo trailer designed to show off the format's full capabilities, original mixer Erik Aadahl used 118 separate objects to create an orchestra of sound ping-ponging all around the audiences. Many Atmos mix moments are much more simple -- a lone helicopter moving, a bit of the orchestral score pulled up into height channels, for example -- but all mixes are filled with dozens of little sounds designed to enhance story and build emotion. 

Tim's job, as the near-field re-recording mixer, is to preserve the integrity of filmmaker intent; he wants to make sure the theatrical experience and the home entertainment experience match. The challenges comes from the fact that most professional cinema auditoriums are (obviously) much larger than our living rooms, media rooms, and dedicated home theatres. Basically, theatrical surround mixes need to "move a lot of air."

A near-field mix is essentially 95% theatrical mix. Yet, if you don't adjust for the home, your Blu-ray might be too loud, all of these moving objects may drown out the dialog, muffled sound or overly bright sounds can be exaggerated, and lastly LFE can overload and become a mess of booming noise. Tim's tweaking generally includes bass management, ensuring dialog clarity, balancing volume levels, and, overall, just making sure you can hear everything the filmmakers intended you to hear.

'The Expendables' re-recording sessions provided their own unique challenge because this Blu-ray includes both theatrical and unrated cuts fused together by seamless branching. Why so hard? First, only the theatrical cut was mixed in Atmos (a 7.1 bed, plus objects). The unrated cut files were delivered in 5.1 stems, leaving Tim to first up-mix the new sound elements -- dialog, sound effects, and music -- to 7.1, and then to Atmos so that anyone watching the Blu-ray could watch either cut of the film, and not know -- from a sound perspective -- where new material branched in. This meant matching reverb and positioning and tones and all other sorts of very intricate aural variables.

As the final part of Tim's demonstration, he played three or four 'Expendables 3' sequences, ranging from action mayhem to a quiet club scene where he had to level the voices of two lead characters. It was also fun to demo individual objects (ie, no other sounds or music) like a helicopter as it whirred around our heads. Interesting to note: Atmos really works well for scores, given mixers a chance to pull the music into the height channels to give a wider feeling.

We then moved from the professional mixing environment to a well-equipped home theatre with awesome KEF speakers. The crazy part? It wasn't a downgrade. Sure, fifteen grand in KEFs isn't exactly a budget setup for everyone. You expect it to sound pretty damned great. But what blew my (feeble) mind was how well bounce-off-the-ceiling Atmos on Blu-ray sounded in a very good, but imperfect room... in direct comparison to in-ceiling Atmos via the original ProTools session in the literal room where it was mixed.

Virtually identical.

That's how incredibly good Atmos in the home sounds when we crack open a Blu-ray.

As I personally prepare to upgrade to Atmos, which may or may not be in the immediate future, I can't help but use these Dolby Events as personal demos -- what sounds the best to the pros? What configuration do I need? What can I afford? At this time, consider me fully in love with 7.1.4 as an optimal Atmos configuration, but perhaps more impressive than this format's ability to recreate The Studio Master, its flexibility to adapt to multiple listening environments. I still don't know if I'll end up with add-on modules or in-ceiling speakers, but I'm happy to note there's zero trade-off between the two. 

Okay, studios, your ball. What titles are you releasing next? When do we get to hear Atmos via VUDU? 


[1]...he said, joking, tongue firmly planted in his cheek... or is it?

#willwriteforbeerandpizza #andhealthinsurance #andspeakers

[2] 'Hercules' too was announced for Atmos, but arrived with a soundmix encoded in 7.1 DTS-HD MA; I'm not sure if it was mixed for Atmos or not.

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Discs mentioned in this article: (Click for specs and reviews)
The Expendables 3 (Blu-ray)
Transformers: Age of Extinction (Blu-ray)
Step Up All In (Blu-ray)
Gravity: Diamond Luxe Edition (Blu-ray)
Teenage Mutant Ninja Turtles - 3D (2014) (Blu-ray)
Tags: Dolby Atmos, 'The Expendables 3', sound mixing, sound re-recording, Blu-ray, home cinema, Home Theater (all tags)