Dolby Atmos – From the Cinema to Your Home Theater

Immerse yourself in a cocoon of sound with Dolby Atmos

Dolby Atmos is a surround sound format introduced by Dolby Labs in 2012 for use in Cinemas that provides up to 64-channels of surround sound by combining front, side, rear, back, and overhead speakers with a sophisticated audio processing algorithm that adds spatial information. The intent of Dolby Atmos is to provide a total sound immersion experience in a commercial cinema environment.

Following on the heels of initial success in cinemas (2012-2014), Dolby partnered up with several AV Receiver and speaker makers to bring Dolby Atmos experience into the home theater environment.

Klipsch Dolby Atmos Speaker Setup
Image provided by The Klipsch Group

Since only the uber-rich can afford to install the same type of Dolby Atmos system that is used in the commercial environment, Dolby Labs provided manufacturers with a physically scaled-down version that is more suitable (and affordable) to consumers to access the Dolby Atmos experience at home.

Dolby Atmos Basics

Pioneer VSX-933 Dolby Atmos Home Theater Receiver

Pioneer Electronics  

With surround processing formats already found on many home theater receivers, such as Dolby Prologic IIz or Yamaha Presence, you can add a broader front sound stage, and Audyssey DSX can fill in the side sound field. However, as sound moves from channel to channel and overhead, you may experience sound dips, gaps, and jumps (now the sound is here, now the sound is there).

For example, when a helicopter flies around the room, Godzilla wreaks destruction, and storms never sound quite right, the sound may appear wobbly rather than smooth as the filmmaker intended. You may not experience a continuous wrap-around sound field when there should be one. Dolby Atmos is designed to fill in those surround sound gaps.

Spatial Coding: The core of Dolby Atmos technology is Spatial Coding (not to be confused with MPEG Spatial Audio Coding) in which sound objects are assigned a place in space rather than to a specific channel or speaker.

Upon playback, the metadata encoded within the content bitstream (such as a Blu-ray Disc or streaming movie) is decoded on the fly by the Dolby Atmos processing chip in a home theater receiver or AV processor. The receiver/processor then makes the sound object spatial assignments based on the channel/setup of the playback equipment.

Setup: To set up the best Dolby Atmos listening options for your home theater (provided you are using a Dolby Atmos-enabled Home Theater Receiver or AV Processor/Amp combination), the menu system will ask you the following questions:

  • How many speakers do you have?
  • What size are your Speakers?
  • Where are your speakers located in the room?

EQ and Room Correction Systems: Dolby Atmos is compatible with existing automatic speaker setup/EQ/Room Correction systems, such as Audyssey, MCACC, YPAO, etc...

Get High: Height channels are an integral part of the Dolby Atmos experience. To gain access to height channels, the user can install either speakers mounted in, or on the ceiling, or employ two new types of more convenient speaker setup and placement options.

  1. Add after-market speaker modules that rest on top of your current front left/right and/or surround speakers.
  2. Add a speaker(s) that can both front and vertically firing drivers encased within the same cabinet.

The vertical driver in these two options directs sound that would normally be produced by ceiling-mounted the speaker to the ceiling, which is then reflected back down to the listener. If placed properly in relation to a low flat ceiling, there should very little difference between this type of speaker design vs using separate ceiling-mounted speakers.

Although the all-in-one "horizontal/vertical" speaker reduces the number of individual speaker cabinets, it doesn't reduce the amount of speaker wire clutter as the horizontal and vertical channel drivers have to be connected to separate speaker output channels coming from your receiver.

The eventual solution might be self-powered wireless speakers, such as the solution provided by Damson.

New Speaker Configuration Nomenclature: Get familiar with a new way to describe speaker setup configurations. Instead of 5.1, 7.1, 9.1 etc... you will see descriptions such as 3.1.2, 5.1.2, 7.1.2, 7.1.4, 9.1.4, etc... Speakers laid on in a horizontal plane (left/right front and surrounds) are the first number, the subwoofer is the second number (maybe .1 or .2), and the ceiling-mounted or vertical drivers represent the last number (usually .2 or .4) – more details in the next section of this article.

Hardware and Content Availability: Dolby Atmos-encoded content on Blu-ray Disc is available (refer to our listing). Dolby Atmos is compatible with current Blu-ray and Ultra HD Blu-ray disc format specifications.

Dolby Atmos-encoded Blu-ray Discs are playback-backward compatible with almost all Blu-ray Disc players.

To access the Dolby Atmos soundtrack, the Blu-ray Disc player has to have HDMI ver 1.3 (or newer)  outputs, and the player's secondary audio output setting must be turned off (secondary audio is usually where things such as the director's commentary are accessed). Of course, a Dolby Atmos-enabled home theater receiver or AV processor must be used as part of the chain.

Dolby TrueHD and Dolby Digital Plus: Dolby Atmos metadata fits within the Dolby TrueHD and Dolby Digital Plus formats. If you can't access the Dolby Atmos soundtrack, as long as your Blu-ray Disc player and home theater receiver are Dolby TrueHD/Dolby Digital Plus compatible, you still have access to a soundtrack in those formats, if they are included on the disc or content.

Since Dolby Atmos can be embedded within a Dolby Digital Plus structure, Dolby Atmos can be used streaming and mobile audio applications.

Processing For Non-Dolby Atmos Content: To provide a Dolby Atmos-like experience on currently available 2.0, 5.1, and 7.1 content, a "Dolby Surround Upmixer" that borrows on the concept employed by the Dolby Pro-Logic audio processing family, is included in most Dolby Atmos-equipped home theater receivers. Look for this feature.

Dolby Atmos Speaker Placement Options

Dolby Atmos Speaker Setup Examples

Onkyo / Dolby Labs  

There are four things you need to access the true Dolby Atmos Experience.

  • A Dolby Atmos-equipped home theater receiver, soundbar, or smart speaker.
  • A Blu-ray or Ultra HD Blu-ray Disc player (most recent model Blu-ray Disc players compatible) or compatible streaming player.
  • Dolby Atmos-encoded Blu-ray Disc or streaming content.
  • More speakers.

Oh No! Not More Speakers!

If home theater speaker configurations weren't already complicated enough, you might want to buy a large spool of speaker wire if you plan to enter the World of Dolby Atmos. Just when you thought you could handle 5.1, 7.1, and even 9.1 - you may now have to get used to some new speaker configurations as shown in the above photo, such as 5.1.2, 5.1.4, 7.1.2, or 7.1.4.

So what the heck do the 5.1.2, 5.1.4, 7.1.2, or 7.1.4 designations actually mean?

Easy-to-Add Speaker Solution Possibilities

Dolby Atmos typically requires adding extra speakers, but Dolby and their manufacturing partners have come up with some solutions that may not mean you have to physically hang or place speakers inside your ceiling.

One solution available is small Dolby Atmos-compatible vertically firing speaker modules can be placed right on top of the front left/right and left/right surround speakers in your current layout - it doesn't get rid of the extra speaker wires, but does make it more attractive than running speaker wire up your walls (or having to go into the walls).

Another option being offered are speakers designed to include both horizontally and vertically firing drivers within the same cabinet (practical if you are putting together a system from scratch or switching out your current speaker setup). This also decreases the physical number of actual speaker cabinets needed, but just as with the module option, it doesn't necessarily cut down on the number of speaker wires you need.

What makes the speaker module or all-in-one horizontal/vertical speaker system work is that the vertically firing speaker drivers are designed to be highly directional, enabling them to project sound so that it bounces off of the ceiling before dispersing into the room.

This creates an immersive sound field that appears to come from overhead. Average living and home theater rooms would have speaker-to-ceiling distances that should work. However, rooms with highly angled cathedral ceilings might be an issue and vertical sound projection and ceiling reflection would not be optimal to create the best overhead soundfield. For that scenario, strategy-placed ceiling speakers may be the only option.

You can get home theater receivers equipped with Dolby Atmos, priced from $400 to $1,299 and $1,300 and Up.

Dolby Atmos in Soundbars, Smart Speakers, and TVs

Yamaha YSP-5600 Dolby Atmos Soundbar

Yamaha

In addition to more home theater setups requiring extra speakers, Dolby Atmos is also being incorporated into select Soundbars, Smartpeakers (such as the Amazon Echo Studio), and TVs (mostly select models from LG).

Here is how this is done.

After Dolby Atmos source material is decoded or a non-Dolby Atmos content source is upmixed, a combination of up-firing speakers built into a soundbar cabinet and/or additional audio processing (Dolby Atmos Height Virtualization) in smart speakers and TVs is employed to a deliver an immersive Dolby Atmos effect.

Although not as accurate as a Dolby Atmos system with added physical speakers placed around the room and on the upper wall or ceiling, it brings a more immersive surround sound experience for smaller spaces and budgets. 

The Bottom Line

The big takeaway with Dolby Atmos is that it's a game-changer for home theater audio.

Starting with sound recording and mixing, to the final listening experience, Dolby Atmos frees that sound from the current limitations of speakers and channels and surrounds the listener from all points and planes where sound can be placed.

From a bird or helicopter flying overhead, to rain falling from above, to thunder and light hitting from any direction, to reproducing the natural acoustics of exterior or interior environments, Dolby Atmos produces a highly accurate natural listening experience.

BONUS: Dolby Atmos Technical Documents