What is Dolby Atmos?

As TV technology continues to improve offering us greater resolution, contrast, and refresh rates, innovations in sound are now available to help us create an immersive, theatre-like experience in our homes. The biggest revolution in home-theatre sound is the introduction of Dolby Atmos.

A photograph of a cinema equipped with Dolby Atmos

The Evolution of Surround Sound

Dolby Atmos is the latest audio standard for creating and delivering movie soundtracks in multiple channels. This is the newest in the evolution of immersive sound moving from mono to stereo to surround sound. Dolby introduced surround sound for home settings in 1982 with Dolby Surround Technology which added a third channel to Dolby Stereo for the surround channel usually placed in the rear of the room. The next leap came with the introduction of Dolby 5.1. in the early 90s. This added a total of four more audio channels, three full-bandwidth channels, and one low-frequency channel. The additional channels allowed for a centre channel, another surround channel, and a sub-woofer.

Dolby 5.1 was a real breakthrough especially for those who purchased high-end amplifiers and speakers and optimised the placement of speakers in the room. In the early 2000s, 5.1 sound became available to many more users as more affordable 5.1 sound bars hit the market.

The Dolby logo with the Dolby Atmos in black text

Introducing Dolby Atmos

Just in time for 4K and now 8K TVs, the next generation of surround sound is here with the introduction of Dolby Atmos or Dolby 7.2.4. While Atmos is new to the home market, it is already in use in hundreds of premium movie theaters. This means that content is already available in this format. Dolby Atmos adds seven additional audio channels. The most exciting performance enhancement is the addition of a height layer in the soundtrack. The height layer is also multi-dimensional. What this means for the movie viewer is that Atmos can create the experience of sound coming from above you and even moving within that vertical and horizontal space.

What does 7.2.4 Mean?

Dolby Atmos is also referred to as Dolby 7.2.4. The 7.2.4 is a reference to the number of distinct audio channels. The seven refers to the number of normal traditional surround channels. These include the front, centre and surround speakers. The 2 shows the number of sub-woofer outputs. Both outputs carry the same low-frequency information. The four is what really makes Atmos unique. It refers to the number of upward or downward-firing speakers. These are the channels that provide the height dimension of the sound experience.

What Equipment Do I Need?

Dolby Atmos initially required a receiver that can decode Dolby Atmos and as many speakers as possible. Dolby recommends at least 11 speakers. Fortunately, manufacturers are now offering ready to use Atmos packages.

For those who want the Atmos experience with a lower cost and much more straightforward installation, Atmos enabled sound bars are now available. Some of the budget options do not offer a true 7.2.4 experience but merely add the height channel through two up-firing speakers built into the bar. There are now new offerings that come with additional satellite speakers that provide a genuinely immersive Atmos experience.

Where Can I Get 7.2.4 Content?

Fortunately, if your Blu-ray player is relatively new, you can already play Atmos content. Many new release Blu-ray discs already have the data for 7.2.4 sound. Streaming services are also beginning to adopt the latest Dolby standard, and the latest versions of streaming devices have Atmos built in.

If you have or are considering buying the latest in display technology, be sure to check out Dolby Atmos. Otherwise, you will be missing out on the incredible sound that goes with your beautiful picture.