Saturday, March 7, 2015

Dolby Atmos: Best Surround Sound Format For Movies Ever?

With relatively good sounding public demonstrations and public appreciations since its launch, will Dolby Atmos become the best surround sound format for movies ever? 

By: Ringo Bones 

As every high fidelity audio and movie enthusiast knew by now, Dolby Atmos is the name of the latest digital surround sound technology that was announced by Dolby Laboratories back in April 2012. Even though it was first utilized in the Pixar made move Brave, many home cinema buffs associate Dolby Atmos with the movie Gravity that stars Sandra Bullock and George Clooney because it is the one oft use to demo the Dolby Atmos capable home theater audio systems currently on sale. Unlike the DTS encoded Mousehunt release circa 1998, the 2013 era Gravity’s Dolby Atmos surround sound audio tracks managed to produce panned sound effects concurrent to what’s actually happening on screen. 

The first officially authorized Dolby Atmos installation was in the Dolby Theater in Hollywood, California fro the premier of Pixar’s Brave back in June 2012. Throughout 2012, Dolby Atmos saw a limited release of about 25 installations worldwide with an increase to 300 locations in 2013. There are currently 2,000 official Dolby Atmos locations worldwide as of February 2015. 

From the film post production audio engineer’s perspective, Dolby Atmos takes advantage of the now industry standard pro audio digital recording platforms first developed during the late 1990s like a re-recording mixer using a Pro Tools plug-in (available  downloadable from Dolby) or a Dolby Atmos equipped large format audio mixing console such as AMS Neve’s DFC or Harrison’s MPC5 to designate a particular location in the theater as a three dimensional placement where dynamic sound source should seem to be coming from. 

The Dolby Atmos digital surround sound technology allows up to 128 audio tracks plus associated pan meta-data to de distributed to theaters for optimal dynamic rendering to loudspeakers based on the typical commercial or home theater’s capabilities. Dolby Atmos was initially geared towards commercial cinema applications only, but was later adapted to home cinema thus the association with the new surround sound format with the movie Gravity since it was the Dolby Atmos encoded DVD that was often used in demonstrating the Dolby Atmos ready home theater audio systems that recently entered the market. In addition to playing back standard 5.1 or 7.1 Dolby Digital surround sound mix using loudspeakers grouped into arrays, the Dolby Atmos system can also give each loudspeaker its own unique feed based on its exact location, thereby enabling many new front, surround and even ceiling-mounted height channels for the precise panning of select sounds such as helicopter or rain – or even those overhead public address speakers in a supermarket.  

During a recent Audio Engineering Society talk by a one of Dolby Atmos’ senior mixers Chris Goodes, with industry VIPs and a few fortunate enthusiasts took a tour of the facility and some demos of the capabilities of Atmos. This particular demonstration room was intended by Dolby Labs to “officially” demonstrate their latest surround sound system was the size of a small to medium commercial cinema. With Atmos in full flight, everyone noticed a greater “seamless” resolution of movement or pans. Instead of an array of side surrounds that act as a single channel, each one can act as an individual channel. This means there is greater control of movement – at least from a post-production audio engineer’s perspective. 

Dolby Atmos’s “object approach surround sound” means that out of over 100 possible simultaneous objects, each one is assigned a 3D location within the cinema space as well as the object having a size. To my ears at least, it is reminiscent of how a typical zero feedback single-ended triode amp does imaging. In a 5 or 7 channel system, we have 5 or 7 speakers which seek to recreate the sound or acoustic event. With Dolby Atmos, the difference is probably best demonstrated in spaces often found in a typical commercial cinema where you might have 10 side speakers rather than the one or two found in a typical domestic home theater setup. Dolby Atmos in actual practice has the ability to pull the sound further away from the screen. I heard this result, too, but whether it is a good or bad thing is entirely up to you. 

Despite the things that it does right, I still have reservations about Dolby Atmos. If Atmos is not done properly or improperly mixed by post-production “audio-cowboys”, it could result in unnatural use of effects coming from the ceiling that don’t belong there – reminding me of that quirky DTS surround sound demo of Mousehunt back in 1998. But when done correctly, like the audio mix in the movie Gravity, it puts Dolby Atmos in the must-have territory for most home theater enthusiasts given that good sounding entry level systems now cost a little over 200 US dollars. From my perspective at least, Dolby Atmos works best when used subtly rather that a post-production audio engineer trying to recreate what they hear that time when they are high on lysergic acid when mixing a chamber music ensemble or a squad-level firefight.     

1 comment:

April Rain said...

According to Dolby's official website, Dolby Atmos is fully compatible with Dolby 5.1 and 7.1 Channel surround sound systems. Probably explains why some premium cable channels here in the Philippines are now "hyping" that their programs are Dolby Atmos encoded even if the customer's audio system is not.