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.