An Introduction to Dolby Atmos
Since its debut in 2012, Dolby Atmos has been enhancing commercial theater with a three-dimensional, lifelike audio experience. Instead of sounds coming from beside or behind the audience, Atmos enables sounds to move around an audience in a three-dimensional space so that listeners feel like they’re truly immersed in the action. This new format requires more speakers than its predecessors, and it can support up to 64 channels.
The addition of ceiling-mounted speakers provides realistic audio effects from overhead. Atmos is more than just a format with more channels than the classic 5.1 and 7.1 decoding schemes; it’s a unique system that differs from other schemes in several ways.
Dolby Atmos is able to deliver this immersive, enveloping sound experience by utilizing “audio objects.” These objects can be comprised of individual sounds or groups of sounds, and the sounds can be either static or moving.
Metadata accompanies these audio objects to deliver crucial information about their movement and location. The Atmos system also utilizes beds, which are groups of audio objects that can be assigned to speakers. This object-oriented approach provides a degree of flexibility and scalability that hasn’t been possible with previous systems.
Atmos in Home Theaters
Recent product releases from manufacturers herald good news for home theater enthusiasts: Dolby Atmos isn’t limited to commercial theaters anymore. Both Denon and Onkyo have rolled out new receivers that support the Atmos format. Similar rollouts have come from manufacturers such as Yamaha and Sony.
With all these product launches, consumers may wonder what gear is needed to start taking advantage of Dolby Atmos at home. The answer will depend on the desired speaker configuration and the hardware already present in the home theater.
A new codec isn’t required to deliver Atmos content; new extensions within a couple of the current Dolby codecs will take care of it. Older receivers will just play the base Dolby TrueHD or Dolby DigitalPlus content, so an A/V receiver that can support the new extensions will be an essential purchase for any home theater enthusiast who wants to enjoy Atmos at home. A Blu-ray player that completely conforms to the specification will also be able to handle Atmos content. Contrary to what some salespeople may claim, no new HDMI cables are needed for a home Atmos setup.
Configuring and Mounting Speakers
A home theater enabled for Atmos can have up to 24 floor speakers and 10 overhead speakers, for a total of 34 speakers in the configuration. According to Dolby, one of their partners will be launching a 32-channel receiver that can reap the full benefits of Atmos’s expandable nature. However, home theater enthusiasts with a more modest setup can still take advantage of Atmos, and they can choose from a variety of configuration options. Consumers who are repurposing their existing speakers for Atmos may need to relocate their overhead speakers, as Atmos setups tend to situate their ceiling mounted speakers in the center of a room. Home theater enthusiasts with X.X.4 setups will get the best results from Atmos, since these systems have superior panning functionality. Dolby maintains that even consumers with X.X.4 systems will still see significant benefits from enabling Atmos.
Another consideration for consumers involves whether to use ceiling mounted speakers or invest in Atmos-enabled speakers with unique reflective speaker technology. Atmos-enabled speakers contain a driver array that’s pointed toward the ceiling; the Atmos engine modifies certain frequencies to create the illusion of sound apparently coming from above the listener. These speakers work best in home theaters with a ceiling height of eight to nine feet, because the enveloping effect of Atmos is somewhat diluted in rooms with higher ceilings. Consumers who may not want to invest in new speakers can take advantage of add-on modules offered by several manufacturers. These add-ons can be placed on top of a front or rear speaker to help create the Atmos effect.
TIP: You can purchase celling speaker mounts for about $25 each and mount Fluance surround speaker form the ceiling for optimal Atmos performance.
Dolby Configurations Explained
A 5.1.2 system uses two ceiling mounted speakers in addition to a normal 5.1 setup.
A 5.1.4 system uses four ceiling mounted speakers in addition to a normal 5.1 setup.
A 7.1.2 system uses two ceiling mounted speakers in addition to a normal 7.1 setup.
A 7.1.4 system uses four ceiling mounted speakers in addition to a normal 7.1 setup.
A 9.1.2 system uses two ceiling mounted speakers, or two Dolby Atmos enabled speakers in addition to a normal 9.1 setup.
Diagrams of all the supported Dolby Atmos configurations using 7.1 through 11.1 channels. Images sourced from Dolby.
Some consumers may wonder if Atmos can only be enjoyed on upcoming movies, or if the system might work with their existing collection of films. The good news is a surround upmixer is present within the Atmos engine, and it appears to work fairly well. The engine is able to analyze a wide range of legacy sources, including older two-channel content as well as modern Dolby TrueHD content. After analyzing the content, the engine can create a fully matrixed Dolby Atmos environment by directing different frequency bands to separate channels.
What’s the Verdict on Atmos?
There’s no doubt that Atmos is going to have a big impact on the audio industry. After years of sluggish A/V receiver sales, this new format will be a boon to retailers and manufacturers. Dolby Atmos also promises benefits for film producers, since movie soundtracks can be created with just one master mix to support any speaker configuration.
Consumers can expect an onslaught of Atmos-related items to be hitting the market soon. However, anyone who may be interested in adopting this new technology will need to make a hefty investment in order to get started. Not only will they need to purchase new speakers, but they’ll also have to get a new receiver. While Atmos-enabled gear may not fit in every home theater enthusiast’s budget, this new format promises to deliver a truly incredible audio experience for any consumer willing to take the plunge.