Getting My Ears Wrapped Around Dolby Atmos for the Home
8/14/2014 11:26 AM
Chances are you’ve heard a good deal of news recently about Dolby Atmos coming to the home market. If you’re totally in the dark, check out my blog, What Integrators Need to Know About Dolby Atmos
to get up to speed on the basics of this new surround standard. I was invited to New York yesterday (August 12) to visit Dolby’s offices—and more importantly, Dolby’s theater—to hear the home version of Dolby Atmos for myself. As an added bonus, I would also be getting the chance to hear Dolby Atmos’ commercial cinema version for the first time, as well, since the nearest Atmos-equipped theater is about 90 miles from my home. Judging from the show of hands in the room, it appeared that many people already had experienced Atmos in a commercial cinema, so it’s likely a large percentage of readers have already heard it for themselves, as well.
Before I dive into some of the details and describe what Atmos Home Theater sounded like, I want to say that I think Atmos is something you should definitely take note of. In fact, Atmos represents the most significant upgrade in home theater audio ported directly from the commercial cinema since Dolby Surround EX was introduced back in 1997 with Star Wars: Episode One: The Phantom Menace. All other additions of height and width channels since them have been matrixed signals derived by the processor with no commercial counterpart or support, meaning there was never a theater mix to experience. This makes Atmos the first really saleable major home theater audio upgrade to come along in 17 years! It also offers a great upsell opportunity for a surround system over a soundbar if clients want to experience the next generation of surround sound audio.
So, here’s what I learned from Dolby in New York…
|To prove I was there...
The morning started out with a quick presentation overview from Brett Crockett, Dolby’s Senior Director Sound Technology Research. He explained that Atmos is an engineered solution based on how the brain processes sound and that Dolby engineers “hacked your hearing” to reverse engineer how we hear and perceive sound. Atmos was introduced in 2012 with Pixar’s Brave, and there are now more than 150 films already mixed in Atmos and more coming all the time.
|Bret Crockett explains Atmos
The biggest difference between Atmos and all other surround formats is that Atmos is not channel based, but rather uses sound objects—up to 128 of them. The metadata in each audio object tells the Atmos renderer where to move the objects around the room. All 128 audio objects from the original theater mix are represented in the home mix, meaning that nothing is lost. Spatial coding takes into account how many objects there are and where they are in space, and the Atmos renderer makes a custom mix of the movie’s audio for your particular listening environment and setup with up to 24 floor and 10 overhead speakers.
Next up was a sit-down Q&A with Craig Eggers, Dolby’s director of home theater marketing. Eggers explained that the idea of overhead speakers translates well from the commercial cinema to the home but that they can be difficult to install or add for many consumers. Because Dolby’s goal is to bring Atmos to as many consumers as possible, it developed the Atmos-enabled speaker to simply part of the process.
|A Dolby Atmos-enabled speaker
Dolby Atmos-enabled speakers will be available from a variety of speaker manufacturers, including Definitive Technology and Pioneer and will feature an extra set of drivers—and speaker binding posts—to drive the top-mounted Atmos speaker. All Atmos-enabled speakers come in to Dolby for testing and certification to meet directivity, range, and performance criteria.
Eggers emphasized that the Atmos renderer is scalable and adaptable and that adding speakers increases the level of immersion and realism for the listener. During setup, the consumer or installer “tells” the Atmos renderer how many speakers are in the system, where they are located, and what frequency range they can handle. This set-up will be done via on-screen GUI and utilize a calibration mic similar to the way receivers incorporate technologies like Audyssey, MCACC (Pioneer), and YPAO (Yamaha) today. It will be left up to each receiver/processor manufacturer as to how to implement this in their systems.
Atmos requires no changes to the Blu-ray or HDMI spec, though the Blu-ray player must be capable of bitstream output (for decoding by the Atmos renderer) and the second audio channel must be turned off. Based on this information, it seems likely that movie servers like Kaleidescape would be able to support Atmos titles when they start appearing later this fall.
“Atmos needs to be experienced,” Eggers said, “and it is a technology that can bring customers into stores and introduce new customers.”
Eggers added, “Atmos represents an incredible opportunity to maximize in-store demo systems.”
I asked Eggers if there were different qualities or performance levels of Atmos renderers and he commented that the renderer is the same in all performance levels of devices, so an entry-level receiver/processor will offer the same rendering capabilities of a high-end model.
Knowing that there are integrators already gearing up to wire for Atmos systems, I pushed him for some specifics on speaker locations. The good news is that Dolby is preparing an Atmos installers guide that will be available at CEDIA EXPO, answering all installation-related questions. I got a look at this 39-page document, and it is very thorough and will offer specifics on speaker placement and location.
Following this session we were led into Dolby’s theater room for a demonstration of Atmos in a commercial theater setting to set an audio benchmark.
|Stairs leading into theater
These demos were presented by Stuart Bowling, Dolby worldwide technical marketing manager, cinema. Bowling wasn’t sure, but thought the theater contained 31 speakers with 14 overhead. (It was difficult to count in the dark room.)
|The Dolby Atmos commercial-style theater
First up were two Atmos trailers, Amaze and Unfold. I have a 9.1 system in my home, so I consider myself a fair judge of surround sound, but it was immediately clear the sound had a far more swirling, encompassing feel, creating a canopy of overhead audio that was far more immersive than the standard side-channel-only mix. I felt wrapped in sound, and the overall audio presentation had a higher plane, getting off the floor and up to screen height and well overhead.
We then watched a lengthy clip from Star Trek Into Darkness, the opening scene where Spock is trying to stop a volcano from erupting and destroying a civilization. There were several audio cues that really caught my ear, including a spear that sounded like it whipped right past my left shoulder, vines snapping all around and a thick cable breaking overhead and snapping across the sound stage. When the Enterprise lifted out of the ocean, there were cracking and groaning sounds of metal overhead, and then lava blasts that you could easily track up and overhead.
“Immersive, cocoon, canopy, spherical,” were the words that I found myself thinking as I listened, and the audio seemed to be a far more present and aggressive part of the storytelling, making for a more involving and engaging experience in a way that current surround speaker layouts can’t match.
Next up was a Red Bull racing clip with an F1 car zipping through a city with terrifically detailed notes of engine noises and tire squeals that were precise and easily localizable in the large space.
Finally was a trailer with audio mixed by Gary Rydstrom and animated by Pixar called “Leaf” which reminded me quite a bit of the old “Jungle Sounds” demo put out by Dolby and THX to demonstrate Surround-EX many years ago. Leaf really let you pick out and track specific sound objects as they moved around the room, and also showed off the 360-degree swirling capabilities of Atmos as the leaf twirled around the room and overhead.
After this we were led into a smaller room to experience an Atmos home theater system.
|Dolby's Atmos home theater demo
This was a 7.1.4 configuration with the standard 5.1-channels augmented with surround back channels, and this seems to be the “sweet spot” of Atmos home theater installs. (While there were front height channels in the room—typical of a Dolby PLIIZ location—we were told they were not in use during the demo.) There were four speakers installed in the ceiling as well as two Dolby Atmos-enabled speakers in the front and rear of the room (serving double duty as front main and surround back) to give us an opportunity to compare the audio of overhead speakers versus Atmos enabled floor speakers.
Peter Razukas, Dolby’s product marketing manager, Home Theater Group, started off by playing the Amaze and Unfold trailers and the Red Bull clip we had just heard in the “big theater.” While it certainly lacked the impact and dynamics of the million-dollar room, it retained the same sense of being enveloped in audio overhead with the soundstage being lifted and raised up from the side walls and overhead.
After this, Razukas played a couple of sound-only clips, first with just the traditional 7.1 configuration and then with the 7.1.4 alternating between the in-ceiling and the Atmos enabled speakers.
The first scene was a helicopter swirling around the room, and while the 7.1 system did a fine job of moving the sounds in a circle, it sounded like it was trapped and pinned to the walls. With the Atmos system enabled, the helicopter now sounded like it was up in the air and circling overhead.
The overhead speakers definitely placed the sound more distinctly overhead, but the Atmos-enabled speakers created a slightly more immersive experience, marrying the ground and ceiling sounds in a smoother way. And the floor Atmos enabled speakers were actually preferable to me in this demo.
Next up was an audio clip of a rain storm, and the Atmos ceiling speakers created a sound that was far more realistic of rain splattering on a roof or umbrella directly over your head, creating a dome of sound that seemed like you had rain pouring down all around you. The Atmos-enabled speakers did a good job of throwing the audio up onto the ceiling, but not as convincingly or as aggressively in my opinion. In contrast the traditional 7.1 system was far more locked at ear level, and seemed like the rain clouds all dropped to the sides of the room.
Having lived with front height channels for quite a while, I felt the Atmos presentations were far more surrounding and spherical. While the front height channels create a very large front soundstage and a proscenium effect that certainly makes for a larger listening space, it is nothing like the true “overhead” audio and lifted soundstage that Atmos delivers.
We then watched a shorter version of the same Star Trek clip where Razukas asked us to guess whether we were hearing the overhead speakers or the Atmos-enabled models. (I believe everyone in the room correctly guessed they were the Atmos enabled and not the overheads, which might tell you something about the differences in the performance and effect.) I listened for the specific audio sounds I had noticed in the big theater—the spear, the chain, the lava—and while the smaller room and Atmos-enabled speakers couldn’t capture the same sense of envelopment and immersion as the big theater, they still had a far more encompassing sound than the traditional speakers and definitely added to the presentation. Unfortunately we didn’t get to hear the scene with the overhead speakers playing.
I would have liked to have spent a good bit of time A/B-ing different tracks between the floor, Atmos-enabled speakers and the overheads, but there just wasn’t an opportunity. In my short demo I would have to say that going with in-ceiling speakers when possible presents a more immersive experience—especially if the current side and rear channels are up off the floor and side-wall mounted—but if that is not in the cards, Atmos-enabled speakers definitely produce a very similar sonic effect.
In our final session, we had a wrap-up Q&A with Crockett where I was able to ask a series of questions I’d been accumulating.
“Are there any special requirements for in-ceiling speakers?”
Crockett said any speakers used for Atmos ceiling channels should have a wide audio dispersion, but almost any good quality in-ceiling speaker should work fine with Atmos, so you can continue installing and specifying the in-ceiling model that best voices with your main channels.
“If someone had an existing surround system with the speakers installed in the ceiling, would that work with Atmos?
Unfortunately, Crockett said, there is really no way to make this work with Atmos since spatially the renderer can’t differentiate between the speakers being in the same/wrong place. He likened this to placing your left and right surround speakers in the front of the room next to the left and right mains; yes, sound will come out of them, but it won’t create the desired effect. The main 5/7 channels in an Atmos system ideally need to be no higher than halfway up the screen height.
“How does an Atmos renderer work with existing audio formats like stereo or Dolby Digital? Can it upscale them?”
Dolby created a new upmixer that will be onboard to utilize all speakers and placing ambience and effects into the ceiling speakers, and existing 2-channel to 7.1-channel content can be enjoyed with enhanced effects on an Atmos system. Of course, purists can turn the upmixing off.
“If a customer only upgrades his receiver/processor, will a 5.1 Atmos mix sound better than 5.1 TrueHD soundtrack?”
Crockett said the Atmos mix should sound more enveloping with more immersion even on a traditional 5.1 or 7.1 system, even without the addition of ceiling channels due to the way that the renderer handles audio objects and the different sound mix. Thus, a customer will get an improvement in their current system (when playing back Atmos coded titles) by upgrading his existing receiver to an Atmos-capable model. Of course, owning an Atmos-capable receiver also opens the opportunity to adding additional speakers in the future, creating more sales opportunities for dealers and a more immersive listening experience for owners.
Far from sounding gimmicky or just another “here’s more speakers!” solution, Dolby Atmos translates from the theater to the home terrifically well and is definitely an evolutionary step in home theater sound. If you are attending the CEDIA EXPO this September consider an Atmos demo as a “must see” item at the show.
John Sciacca is principal of Custom Theater and Audio in Myrtle Beach, SC.
2 comment(s) so far...
By Larry Pexton on
8/14/2014 4:29 PM
Re: Getting My Ears Wrapped Around Dolby Atmos for the Home
An excellent article which summarizes the potential and appeal of the Dolby Atmos system very well. We are proud of the role we played in helping Dolby develop the Dolby enabled speakers and speaker standards. The front and rear speakers pictured in the article, were the early Triad prototypes provided to Dolby, though the ceiling speakers were not ours.
Triad's latest and certified Dolby enabled speakers will be featured in the Dolby demo room #180, along with Triad's InCeiling Bronze/8 LCRs, and should be worth a listen at CEDIA EXPO.
Triad Speakers, Inc.
By Richard Harper on
8/18/2014 9:05 AM
Re: Getting My Ears Wrapped Around Dolby Atmos for the Home
I can't wait to get these :)