Dolby Atmos vs. Dolby Digital | AV.com Blog (2024)

Ready for a sonic showdown? Next into the ring, it’s Dolby Atmos vs. Dolby Digital!

Dolby Atmos is a surround sound technology launched in 2012 – 20 years after Dolby Digital first entered the scene. Atmos is built on the codec of Dolby Digital Plus (also known as Enhanced AC-3, a more advanced version of Dolby Digital). Dolby Atmos adds a vertical dimension to audio, which is object-based rather than channel-based, and supports up to 128 audio tracks.

Contemplating which system you should choose for an all-new theatre build or upgrade? AV.com is in the commentator’s box with the low-down on each contender.

We’ll explore how each technology works, how they came about, and how they sound. We’ll carefully assess their strengths and weaknesses in our quest to crown the winner of this Dolby duel.

Let’s start with a comparison of some key features.

Dolby Atmos vs. Dolby Digital

Dolby Atmos

A Brief History of Dolby Atmos

Remember those moments in the cinema, when the lights dimmed and the Dolby logo illuminated the screen? It was a welcome signal that the trailers were over (thank goodness).

Or perhaps you remember that same logo from your favourite DVD or video game cases—a promise of captivating sound quality. This is the legacy of Dolby Laboratories Inc., a pioneer in audio technologies since its inception by Ray Dolby in 1965.

From their first breakthrough, the Dolby A-type noise reduction system, to the present day, Dolby has continually expanded their technological prowess to embrace audio encoding/compression, spatial audio, and even HDR imaging.

Their most recent and significant cinematic surround sound innovation is Dolby Atmos. This groundbreaking technology was unveiled in April 2012 at the legendary El Capitan Theatre in Hollywood during the premiere of Disney-Pixar’s Brave.

Beyond commercial cinemas, Dolby Atmos has become a leading sound technology incorporated into home cinema equipment, such as AV receivers, since approximately 2016.

What Exactly is Dolby Atmos?

Dolby Atmos is a breakthrough surround-sound technology brought to us by the now San Francisco-based Dolby Laboratories. It goes beyond the traditional 5.1 and 7.1 sound setups by handling up to 128 audio tracks and their respective spatial-audio metadata.

This metadata contains details like the location, movement, panning, speed, and dynamics of an audio track. Such data is processed by Dolby Atmos and distributed accurately across the most suitably positioned channels.

Dolby Atmos expands upon the existing framework of Dolby Digital (and Dolby Digital Plus) in four main ways. It adds:

1. Object-based audio which can be positioned anywhere in a 3D space rather than being tied to specific speaker channels
2. A vertical dimension to audio via overhead and up-firing speakers
3. More layers, i.e., support for up to 128 audio tracks and 64 unique speaker feeds
4. Greater compatibility across new devices and products

Setting Up Dolby Atmos: Channels, Speakers, and Tracks

When we say that Dolby Atmos supports up to 128 tracks, 64 speaker feeds, and different channel configurations, what do we mean?

Audio tracks refer to the individual layers of sound that are mixed to create the final soundtrack. These can be layers of things like dialogue, music, ambient noise, and sound effects. In the case of Dolby Atmos, up to 128 of these tracks can be used at once, providing a high level of detail and complexity in the sound.

Speaker feeds are the unique audio signals sent to each speaker. Dolby Atmos can support up to 64 of these, meaning it can send different sounds to up to 64 speakers simultaneously. If you’re on the hunt for Dolby Atmos speakers, we recommend the Fisual IC65 Installation Ceiling Speaker, KEF R8 Meta Dolby Atmos Speakers, and Klipsch R-40SA Height Speakers.

Channels refer to the predefined areas in the sound field that sounds can come from. A 7.2.4 Dolby Atmos setup, for example, would mean there are seven channels at ear level located around the x and y axes of your room, two low-frequency effects channel (subwoofer), and four overhead channels.

While you could use as many or as few speakers as you like, Dolby Atmos is meant to be a 3D surround sound experience. Therefore, configurations like 2.0.2 or 3.1.2 won’t quite cut it. While you’ll benefit from the overhead sound effects, you won’t be truly surrounded.

We recommend experiencing Dolby Atmos with at least a 5.1.2 speaker configuration, but ideally, you’d have four height channels, as Dolby themselves recommend. These height channels could be ceiling speakers, Dolby Atmos-enabled speakers, or a Dolby Atmos-enabled soundbar.

How Does Dolby Atmos Sound?

Because it introduces a three-dimensional sound field, Dolby Atmos surrounds the listener with sound on all sides. Details from the source material’s various audio track layers are processed and projected in appropriate directions such as left, right, back, front, up, down, and any diagonals in between.

To visualise this in action, imagine you’re watching a film with an intense police chase. You hear the chopping sound of a helicopter approaching overhead, sirens wailing to either side, the revving of a speeding motor ahead, and the anxious dialogue unfolding between characters over the police radio carried crisply over all else. This realistic mimicking of sound positions makes it that much easier to get lost in your favourite TV shows and films.

Where is Dolby Atmos used?

Since its launch in 2012, Dolby Atmos has permeated various aspects of popular media including video streaming platforms like Netflix, Amazon Prime Video and Apple TV+. You can also benefit from its spatial audio effects with subscriptions to music streaming services like Apple Music, Amazon Music, and TIDAL.

More and more we’re seeing re-recording mixers and sound designers remastering the classics of film, TV, and music for Dolby Atmos and other 3D sound technologies. So, if your favourite works aren’t available to experience in full Dolby Atmos yet, never say never.

It’s still new!

Dolby Atmos is still relatively new and has yet to become universally compatible with all forms of media. What’s holding it back? It has more demanding hardware requirements than older systems; you need either a dedicated home theatre with ceiling speakers or special upward-firing speakers, or Dolby Atmos-enabled sound bars or TVs.

In addition, the media content itself needs to be specifically mixed for Dolby Atmos.

Despite this, the number of Dolby Atmos-compatible devices and content is growing rapidly. In the Dolby Atmos vs. Dolby Digital debate, the former is certainly the more futureproofed!

Dolby Digital

The history of Dolby Digital

Dolby Digital was conceived in 1986 with the primary objective of introducing digital sound to 35mm films in cinemas globally.

The concept evolved out of an idea planted by Nasir Ahmed in 1972. However, it wasn’t until 1987 at the University of Surrey that Ahmed’s concept was modified and executed successfully.

Dolby Laboratories combined the ‘modified discrete cosine transform’ algorithm (some very fancy maths), with perceptual coding principles (which is all about how we humans hear sounds). The result? The incredible AC-3 audio, the backbone of the Dolby Digital sound we know and love.

In 1992, Batman Returns was the first film to use 5.1 surround sound with Dolby Digital. Thereafter, it became the standard format and a significant milestone in digital audio technology.

What exactly is Dolby Digital?

Dolby Digital is an established entertainment technology that compresses multichannel audio files efficiently, enabling a full 5.1-channel audio mix in films, DVDs, games, and TV broadcasts.

The technology behind Dolby Digital transforms analogue signals into digital data via encoding. This digitised audio, adaptable to various distribution forms, is then decoded in devices like cinema processors or home electronics for playback. To make sure the sound quality is consistent across different devices, Dolby Digital uses special instructions called metadata that are formulated when the sound is first created.

Setting up Dolby Digital

Setting up Dolby Digital is quite straightforward. Unlike Dolby Atmos, which involves many channels to create a 3D sound environment, Dolby Digital can be used in systems as small as 2.0. However, the standard configuration, and what we would recommend, is 5.1 – i.e., five ear-level speakers and one subwoofer.

In further contrast to Dolby Atmos, Dolby Digital is two-dimensional, so you won’t need to worry about installing overhead speakers.

The key to setting up Dolby Digital systems is to focus on angle and distance, not just horizontal placement. In a 5.1 setup, surround speakers go behind or beside you. Front speakers should angle 45 to 60 degrees towards your listening spot. Also, keep speakers as far apart as they are from you for the best sound.

For more advice about speaker placement and optimisation, check out this guide!

How Does Dolby Digital Sound?

Since Dolby Digital has been the industry standard for a while now, you’ve likely already encountered it in use at your local cinema or while gaming at home. But if you haven’t, here’s the lowdown on what to expect…

• More depth and realism than a plain, monophonic output
• A more immersive, realistic surround sound placement compared to plain audio
• High bit rate and large file compatibility
• Up to five discrete full-range channels: left, centre, right, left surround, and right surround
• A sixth channel for powerful low-frequency delivery

However, spoiler alert, in the Dolby Atmos vs. Dolby Digital showdown, Dolby Atmos beats all of those bullet points.

Where is Dolby Digital used?

While Dolby Digital was initially rolled out for cinema, it has now become an established industry standard across TV, DVD, and video game releases. All HD broadcasts in the U.S., and every DVD globally, use Dolby Digital.

Streaming services such as Netflix, Vudu, and Amazon Fire TV also utilise Dolby Digital Plus-encoded media. Thus, leading us nicely into our next section…

Dolby Digital Plus

Also known as Enhanced AC-3, Dolby Digital Plus is a more advanced version of Dolby Digital. It expands the number of surround sound channels offered from 5.1 to 7.1. It also boasts less compression and higher data rates to provide an all-round enhanced quality of surround sound.

Dolby Digital Plus, like Dolby Digital, uses encoding and decoding algorithms to store and transmit high-quality digital signals that are consistent across an abundance of devices. And speaking of devices, the latest Apple iOS, macOS, and tvOS devices, as well as Windows 10 and Microsoft Edge, all natively support Dolby Digital Plus.

If you’d like an in-depth comparison of Dolby Digital and Dolby Digital Plus, let us know. But for now, lets draw some conclusions.

Pros and Cons of Dolby Atmos

Which is better?

So, which is better: Dolby Atmos or Dolby Digital? Should you upgrade? And which system should you choose for a new home cinema?

The team here at AV.com resoundingly agrees that the winner – by a country mile – is Dolby Atmos.

If you have the necessary budget and space in your home cinema room, definitely consider Dolby Atmos. We can’t recommend it enough.

Dolby Atmos’ 3D object-based system provides a superior audio experience to Dolby Digital. It will help futureproof your system for longer since Dolby Digital is now over 30 years old.

If you can choose, Dolby Atmos is the better choice for your home and devices, offering an unprecedented level of immersion and realism.

With that said, if budget or space is a concern, Dolby Digital is still a globally recognised standard in audio technology that delivers a great home theatre experience.

FAQs

Is Dolby Atmos really that much better?

Dolby Atmos is significantly more advanced and realistic sounding than Dolby Digital. As well as being two decades newer, Dolby Atmos is recognised as the benchmark for commercial and home cinema.

Does Dolby Atmos include Dolby Digital?

Dolby Atmos includes Dolby Digital; the former is simply an extension of the latter’s framework. If you have Dolby Atmos you will be able to decode Dolby Digital content. However, if you have Dolby Digital only, you cannot decode Dolby Atmos content.

Does Dolby Digital sound better?

Dolby Digital does not sound better than Dolby Atmos because it is a 2D, rather than 3D, surround sound format. The newer and more advanced technology of Dolby Atmos beats Dolby Digital by using up to 128 audio objects distributed across up to 64 unique outputs. Dolby Digital also offers lossy compression whereas Dolby Atmos is lossless.

Final thoughts

So, there we have it – Dolby Atmos vs. Dolby Digital. Whether you’re team Atmos or team Digital, you’re sure to get some seriously elevated audio. Why not check out our range of Atmos speakers via the link below?