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How To Deploy a Dolby Atmos Home Theater

By Chris Boylan and Rachel Cericola

Dolby Atmos is coming to a home theater near you, and it may change the way that you experience audio. The format was first unveiled back in 2012 and installed in a select group of movie theaters around the world. Since then, over 100 movies have been encoded and released in the object-based three dimensional surround sound format. Now, Dolby and its partners in consumer electronics are bringing that same theatrical experience to the living room or dedicated home theater. But if you want to bring the Dolby Atmos experience home, you're going to need to upgrade some of your gear. Here are the basics you'll need to consider when deploying a Dolby Atmos system at home.

Works with Your Existing Gear (Mostly)

The good news is that Dolby announced that Atmos-encoded content can be delivered via existing Blu-ray players and streaming set top boxes. Dolby has figured out a way to enhance the existing Dolby TrueHD and Dolby Digital Plus surround sound formats to include the information required by Dolby Atmos. So your existing Roku box will be able to deliver Dolby Atmos titles over Vudu or Amazon Prime using Dolby Digital Plus. And your current Blu-ray player will be able to deliver the new Dolby Atmos-compatible titles using Dolby TrueHD. Just set your Blu-ray player to bitstream output (and disable any secondary audio), pop in a Dolby Atmos Blu-ray Disc and you're good to go, at least from a player perspective.

Speaker Makers are Smiling Right Now

In terms of system enhancements, you're going to need a few more speakers. These can be traditional in-ceiling speakers that provide sound from above or they can be Dolby Atmos-enabled speakers. The latter can deliver that overhead sound, without actually being installed on the ceiling. Speaker companies such as KEF, Atlantic Technology and Definitive Technology have all shown Dolby Atmos-enabled "elevation modules." These are designed to sit on top of your current speakers and bounce sound off the ceiling in order to create sound from above. Other companies including Pioneer have released a new suite of tower and bookshelf speakers that include both the main speakers and the height speakers in the same cabinet.

dolby-atmos-surround-diagram
Traditional in-ceiling or on-ceiling speakers and Dolby Atmos decoding can be added to a standard surround sound system in order to create the 3-dimensional Dolby Atmos soundstage.

Dolby-Atmos-enabled
Dolby Atmos-enabled speakers bounce sound off the ceiling in order to create sound from above.

Whichever speaker options you choose, you're going to need the most important piece of the Dolby Atmos equation: the Dolby Atmos-enabled receiver or preamp/processor. The receiver or pre/pro is the "brains" of the operation. It's what takes the Dolby Atmos-encoded movie or music program from your Blu-ray player or streaming set-top box and decodes it into the channel-based signals that your speakers can understand.

A receiver includes all the decoding, source switching, processing and amplification to drive your speakers.  A preamp/processor is similar but includes no power amps so it can't drive speakers directly -- it needs separate power amps for that. High-end home theaer systems are typically built around preamp/processors and separate power amps, but today's top of the line receivers can give separates a run for their money. Just be sure your receiver or pre/pro supports the number of speakers you want to use for your specific listening room.

By The Numbers

In standard surround sound, we've gotten used to identifying the number of channels in a system using two numbers with a dot in between them: 5.1 means five surround channels (front left, front center, front right, surround right and surround left) and one LFE channel which is typically sent to a powered subwoofer. A system that uses two subwoofers instead of one is normally referred to as ".2" (e.g., 5.2 or 7.2) even though both of those subwoofers are typically driven by a single LFE channel from a receiver.

In Dolby Atmos-land, we now need additional speakers above the listener, so we're going to need new nomenclature. It's pretty simple: just add a number to the end for the number of height speakers you're using. So a Dolby Atmos 5.1.4 system uses five surround channels, one subwoofer and four height speakers. A Dolby Atmos 7.2.4 system uses seven surround channels, two subwoofers and four height speakers. See how that works? It's pretty straightforward.

avr-x5200w
Denon's AVR-X5200W receiver is available today and supports Dolby Atmos decoding.

The minimum configuration for Dolby Atmos at home is 5.1.2 (traditional five-channel surround plus two height speakers) but the Dolby Atmos spec for home can go all the way up to 24.1.10 (yes. that's 35 speakers!). Based on the demos we've heard, we'd recommend four height channels for best effect, so that means a 5.1.4 or 7.1.4 configuration for most rooms. Keep in mind that some receivers support more speakers than they can actually drive, so you may need to add on a stereo amplifier in order to get your preferred configuration. Check out our Dolby Atmos Receiver Buyer's Guide for more details.

Now Bring on the Software!

Once you've got all the hardware elements in place, you're going to need some software. So far, VUDU and Amazon have pledged support to stream titles in Dolby Atmos, but no specific titles or dates have been announced. On the Blu-ray front, only one title has been released with Dolby Atmos-encoding: Transformers: Age of Extinction. Dolby says that the studios will release more Atmos-enabled titles over time. There are certainly plenty to choose from as over 100 films have been released worldwide in Dolby Atmos in the past two years, including quite a few blockbusters.

To tide you over until the library of available titles increases, Dolby Atmos receivers and processors also includes a Dolby Surround upmixer feature, which extracts height information from standard surround sound mixes. We haven't had a chance to listen to this yet, and it certainly won't compare to a discretely encoded Atmos mix, but it may be worth experimenting with, for early adopters of Dolby Atmos at home.

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