Dolby Atmos Explained
Dolby Press Release:
Dolby Atmos®, the revolutionary cinema sound technology, has come to home theaters.
With Dolby Atmos, content creators can precisely place and move sounds anywhere in your
living room, including overhead, to make entertainment incredibly immersive and lifelike.
This white paper is designed to explain how Dolby Atmos will work in home theaters and
how you can build a Dolby Atmos enabled system or upgrade your existing system to
support Dolby Atmos. This paper also explains the technological components of Dolby Atmos
in home theater and the tools that content creators and broadcasters will use to create and
deliver Dolby Atmos content to homes.
Why replace channel-based surround sound?
Dolby Atmos is a revolutionary technology that moves beyond the paradigm of channelbased
audio, which has gone as far as it can in the home.
Dolby has led home theater technology since the late 1980s, when we introduced four channel
Dolby® Pro Logic®. We led the development of 5.1 and then introduced 7.1
surround sound in the home and the cinema. But as home theater expanded to 9.1 and
even 11.1 systems, the problems of pursuing more and more channels became clear. Home
theater content often originates from theatrical content that is mixed, at best, in 7.1 sound
and many times in 5.1. That meant that 9.1 or 11.1 systems reached a point of diminishing
returns in parsing and upmixing that limited signal to serve more and more channels.
In addition, the ability to recreate reality using channel-based audio is inherently limited. In
real life, sounds move in specific and sometimes complicated ways—a hummingbird flies off
a tree branch, hovers in front of a pair of blossoms, and then dives down to a fountain for a
drink. Simply moving the hummingbird’s sound from the Left Height channel to the Right
Front channel can’t possibly recreate the detail of that bird’s flight. And when you lose those
details, it detracts from the brain’s sense that what it’s watching is real.
A cinema solution
Dolby first started investigations into a solution to the problems of channel-based audio in
the cinema. Our goal was to free filmmakers from the limitations of audio channels by
developing a system that allowed them to determine exactly where a sound should be and
where it should move in three dimensions—that is, to faithfully recreate that hummingbird’s
flight in all its complexity.