You’ve probably heard of Dolby Atmos. The name appears on movie theater billboards. You’ll also see it in ads for new TVs and soundbars. Even Netflix and other streaming services say they offer it. But what is Dolby Atmos, and why is it an audio feature worth having and experiencing?
In this Dolby Atmos Beginner’s guide, we’ll take an in-depth look at Dolby Atmos, where it came from, and how to get it in your home. And we’ll answer your questions about this immersive audio technology.
Table of Contents
What is Dolby Atmos?
Dolby Atmos is a type of surround sound. But instead of just delivering sound from the front, sides, and rear of the room, Dolby Atmos adds a ceiling layer. This puts the audience in a three-dimensional listening space. Some say the experience is like being inside an “orb” or “sphere” of sound, which is why we refer to Dolby Atmos as an immersive audio format.
Dolby Atmos is a revolutionary technology that delivers multi-channel audio to an audience. It debuted in theaters in 2012 with the release of the Pixar movie Brave. You can now experience Dolby Atmos in over 6,000 movie theaters in 90 countries. But there are also many ways you can use it in the home, too.
Think of this audio format as a workflow. Sound designers in studios mix movies and TV shows with immersive audio. You can then enjoy the results in a movie theater, from your TV or devices, or even headphones.
But unlike 5.1 or 7.1 surround sound, Dolby Atmos adds an all-important ceiling layer using height speakers. It’s also different in one key respect: Dolby Atmos can use up to 128 “objects” or “nodes,” which is why we refer to it as “object-based audio” (OBA). A professional sound designer or mixer in a studio can place sounds anywhere within a three-dimensional space.
Because Dolby Atmos is scalable, in theory, it doesn’t matter how many speakers you have in a home cinema (within reason). The tech can support up to 64 discrete feeds or individual speakers in a theater. You can even max out a home theater layout for 24.1.10. This comprises 24 ear-level speakers, one low-frequency effects channel, and 10 height speakers!
Key Features of Dolby Technology
Dolby immersive audio makes you feel even more like you’re in the center of the action when watching a movie or TV show, or playing a game. Sound cues feel more realistic because it allows a three-dimensional soundstage with speakers to the front, sides, rear, and above you.
It’s now easier for a sound mixer to place sounds in a precise location, making the experience for the audience more engaging. Imagine a helicopter flying overhead or trees rustling in the wind. Now you can feel the sensation of a fly buzzing around your ear or become immersed in an underwater world.
Dolby Atmos dialog, music, and effects are not limited to vertical or horizontal movement. Now, those sounds can move anywhere within the space. For example, an aircraft can take off behind you to the left, fly over your head, then climb into the sky to the front and right.
The History of Dolby Atmos
But how did we arrive at Dolby Atmos, and what is the history of the tech? Most sound technologies we enjoy at home started life in the cinema. That’s even true for two-channel stereo sound. Surround sound dates back to 1938 with Disney’s specially designed “Fantasound” roadshow system for Fantasia.
When studios had to compete with TVs arriving in homes in the 1950s, analog surround sound formats started to appear in movie theaters more widely. But it was the advent of Dolby Stereo in 1976 which started to change the landscape.
Four channels of “matrixed” audio could be embedded in two analog optical tracks on the side of 35 mm film. This less expensive tech meant thousands of movie theaters could show films with discrete left, center (mostly for dialog), right, and mono surround channels.
Theater audio systems went digital in 1992, with Dolby, DTS, and Sony entering the arena. Dolby Digital 5.1 debuted in cinemas with Batman Returns. The audio system comprised discrete left, center, right, left surround, and right surround channels.
A subwoofer also had a dedicated LFE (low-frequency effects) channel. This was like the layout that DTS used with the theatrical release of Jurassic Park (1993).
Although 5.1 is now considered the base level of movie surround sound, Dolby and DTS later developed 7.1-channel digital sound for the theater and home. These systems added another pair of left and right rear wall channels.
As Dolby and other companies always look to expand their business portfolios, it was natural that surround sound would evolve again. By the 2000s, Dolby, DTS, and Auro Technologies were working on immersive or object-based audio systems.
Today, the three major immersive audio systems we have are Dolby Atmos, DTS:X, and Auro-3D.
Some Common Dolby Atmos Terms
Before we start going over how to achieve Dolby Atmos or immersive audio in the home, let’s look at some common terms you should become familiar with when it comes to the Dolby universe.
- Dolby Atmos-Enabled refers to Dolby Atmos licensed speakers, which radiate sound up toward the ceiling, giving the impression of sound coming from above the listener.
- Upfirer or Upfiring Module are also names for speakers which radiate sound upwards before the reflected signal arrives at the listening position.
- Height Speaker refers to speakers which are either ceiling-mounted or Dolby Atmos-enabled.
- Speaker Layout Identifiers typically appear as 7.1.4 or 9.2.6. The first number represents the number of base- or ear-level speakers, the second is the number of subwoofers, and the third is the number of height speakers in a home configuration
Dolby Atmos in the Home
Now, let’s go over how to enjoy the audio system in your home. Remember that to reproduce Dolby Atmos with home speakers and enjoy its benefits, you need compatible content, a means to play that content, and an audio system to hear the results
Software and Content
Let’s look at which content can provide a Dolby Atmos soundtrack. The first Blu-ray disc to use Dolby Atmos audio was Transformers: Age of Extinction in 2014.
More recently, the major studios and distributors have reserved Dolby Atmos for 4K UHD Blu-ray titles, not standard Blu-ray discs. Always check the disc’s packaging to see the formats available.
On streamed and broadcast TV content, the Dolby Atmos signal “piggybacks” on lossy Dolby Digital Plus, so you won’t get the same audio quality as on a Blu-ray disc. These services have less bandwidth to include the higher resolution signal.
Players and Devices
Of course, you will need a device that can play Dolby Atmos. Most device manufacturers clarify in marketing materials if their products can reproduce the immersive format.
If you’re choosing a new Blu-ray player, in most cases, you’ll need one capable of playing 4K UHD discs. Most Dolby Atmos content comes on these higher-resolution discs. At a minimum, immersive audio must be carried between devices over HDMI, and devices must include the HDMI 1.4 (or later) specification.
There are game consoles, PCs, TVs, cable boxes, phones, and tablets that can decode Dolby Atmos audio. You can also get the experience from headphones (or a headset like the Astro A50) connected to a device that can take advantage of the format. Dolby Atmos over headphones can give the impression of a 3D immersive sound field very effectively.
Receivers, Speakers, and Audio Systems
If you want to recreate the same kind of audio that you hear in a Dolby Atmos theater, you should consider buying an AV receiver. Many AV receivers now decode Dolby Atmos sound. You can also use a receiver to switch between your content sources and use all the audio processing features.
Dolby recommends that the best way to experience Dolby Atmos in the home is to use a 7.1.4 speaker layout. This is what Dolby considers the minimum to recreate the full effects of the format at home.
It consists of seven ear-level speakers (left, center, right, left surround, right surround, left rear surround, right rear surround, left front height, right front height, left rear height, right rear height, and a subwoofer).
If you’re thinking of going big, there are 16-channel receivers and preamp processors that allow you to set up a 9.1.4 or 7.1.6 layout. For many people, that kind of setup is too much for the home.
But as a minimum, you should be thinking of a 5.1.2 system. This will require at least two front-height speakers and a basic left, center, right, left surround, right surround, and subwoofer setup.
Many soundbars on the market can reproduce Dolby Atmos and sometimes DTS:X sound. Along with two or three front-facing speakers inside a soundbar, a couple of the speakers on the topside of the unit might be used for “upfiring” audio toward the ceiling. This delivers a sense of improved spaciousness and the partial benefits of immersive audio.
You might see a soundbar listed as offering a 2.1.2 speaker configuration. It has two forward-facing speakers, one subwoofer, and two upfiring modules. More expensive and feature-rich soundbars carry many more channels and can be more effective at creating a true Dolby Atmos speaker experience.
Some manufacturers still offer home-theater-in-a-box (HTIB) systems which include all the required components for Dolby Atmos. Check out Sony’s excellent HT-A9 system, which has upfiring modules located on the top side of the front and surround speakers.
Dolby Atmos Speaker Placement
Let’s assume you’re going to take the route of setting up a receiver and a full Dolby Atmos speaker system. There are many theories on how best to place speakers in a Dolby Atmos layout in the home. But Dolby has produced several excellent guides on how to optimize your system.
In a 5.1 or 7.1 speaker configuration, the speakers, or satellites, should be at ear level (rather than above ear level). This will help to make the top layer of speakers more detectable.
Dolby Atmos Speaker Setup Guide
If you’re setting up a 7.1.4 system, the four ceiling speakers can be flush-mounted or hung from brackets. When using more directional speakers, they should “toe in” toward the listener. If the speakers have a good off-axis response, they can point straight down.
If making holes in the ceiling is not an option, there are many excellent Dolby Atmos-enabled speakers. These are sometimes known as “upfirers” and are Dolby-licensed and approved speakers that point their drivers toward the ceiling. This gives the illusion that the sound is coming from above.
There are excellent models from companies like KEF, Elac, and Atlantic Technology. But the best results usually come from using in- or on-ceiling speakers, if your room will allow it.
Tips for Ensuring the Best Sound Experience
It’s extremely important to use your AV receiver’s in-room calibration or room correction system when you set up your home theater. Most receivers will walk you through the process, and a microphone is usually included with the product.
Room correction usually measures the distances to the main listening position, ensures the levels of each speaker are correct, and optimizes the speakers’ sound in your room. Setting up an Atmos speaker system usually means connecting many speakers, so it’s important to have them sounding their best.
You can also improve the acoustics in your room by using a few tried and tested techniques. Turning the speakers in towards the listening position can result in better on-axis performance for the audience and reduce the effects of first reflections on side walls. Using a carpeted room, scattering soft furnishings, and even using side or rear wall bookshelves can help to improve the overall home theater sound.
The Benefits of Using Dolby at Home
As we explained in the opening sections, Dolby Atmos gives you the benefit of getting totally immersed in the on-screen action, be that from a movie, TV show, game or even music.
It gives the audience a chance to feel closer to the action by placing them in an orb or bubble of sound. Now sounds come from above you, as well as from the front and sides. In this respect, Dolby Atmos is an enhancement of 5.1 or 7.1 surround sound.
Many homes now have much bigger TVs or even projectors and screens to enhance the experience along with the audio. So, going bigger on the sound makes sense for a lot of consumers today. As George Lucas famously said, “Sound is 50% of the movie-going experience.” We couldn’t agree more with him.
Some people are disappointed that they don’t hear more sound coming from the height speakers in their Dolby Atmos speaker systems. But keep in mind that sound designers do not always choose to use the height channels when mixing and mastering content. Often, the heights are used just for subtle atmosphere or effects.
Frequently Asked Dolby Atmos Questions
Does Dolby Atmos make a difference?
Yes. You will notice a much greater sense of immersion with Dolby Atmos than 5.1 or 7.1 audio. You are now inside a three-dimensional audio space, so the sonic experience is more realistic and natural.
How many channels do you need for Dolby Atmos?
Dolby recommends 7.1.4 as the optimal speaker layout in the home. But as we have discussed, you can settle for 5.1.2 if you are constricted for space or by budget. You can also get Dolby Atmos from a soundbar with as few as two upfiring modules in a 2.1.2 arrangement.
What is the difference between Dolby Atmos and DTS:X?
You will find that some Blu-ray discs support DTS:X instead of Dolby Atmos. DTS:X tops out at speaker layouts of 7.1.4 (or 11.1). However, DTS:X doesn’t require height speakers, so it will down-mix to a 5.1 or 7.1 speaker layout, too. Some high-end AV receivers and processors can decode DTS:X Pro, which is similar to the theatrical version of the format. DTS:X Pro can support up to 30.2 loudspeakers.
Which is better, 7.1 or Dolby Atmos?
That’s a difficult one to answer, and it really comes down to taste and budget. You can spend thousands of dollars on a superb 5.1 or 7.1 system or not that much on a Dolby Atmos system. If you already have a great 5.1 or 7.1 system and choose to upgrade your receiver to a Dolby Atmos model, you’ll reap the benefits of greater immersion and involvement in your chosen content.
Final thoughts on Dolby Atmos
As with all buying decisions, you’ll need to work out your budget and what you can realistically afford if you want to make the leap into the immersive audio world. You don’t have to spend much to get at least some of the benefits of Dolby Atmos. But if you want the kind of experience you get in the theater, you’ll have to spend a lot more, so it’s best to keep that in mind.
Also, take our word for it, and do the necessary planning! If you can’t put speakers in the ceiling, don’t buy them — there are other solutions. If you haven’t got room for large subwoofers on the carpet, save them for another day. There are Dolby Atmos licensed products, systems and devices to suit every occasion and budget, and doing the preparation is half of the work.
Dolby Atmos brings another dimension of audio into the home. Getting three-dimensional sound in your AV room can be an awe-inspiring experience. If you’re curious and are thinking of taking the leap, we hope this guide has helped. In the meantime, let’s just hope that the next immersive audio tech to come down the pike doesn’t involve buying more speakers!
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