What Is Dolby Atmos?
Dolby Atmos is an Object Based audio surround system (similar to competing DTS:X and Auro 3D systems). Object based systems are a combination of raw audio channels and metadata that describes the spatial position (in 3D space) and other properties of audio objects. Atmos (and DTS:X & Auro) add height speakers to create a true 3D sound field (5.1 is a 2D sound field).
So Atmos objects are not always locked to a specific channel (speaker), for example, an object can be set to appear in a 'phantom position' (between speakers), or can appear to move between any speakers in the speaker array in any direction. Atmos supports up to 128 simultaneous independent audio objects in a mix.
Furthermore, the intended spatial position can be rendered fairly accurately regardless of the actual speaker positions based on the actual Atmos speaker setup during installation, which will include a microphone and software in the AVR to measure speaker distances and gain (volume). The actual individual amplifier output is created during playback based on a combination of encoded mix and the speaker configuration (installation). However, more speakers will provide a better resolution of sound movement.
Dolby Atmos for Home, as delivered on Blu-ray and streaming services, are limited to 16 amplifier channels (similar an 'old' system 15.1 - However, as stated above, unlike traditional multichannel audio systems each channel is not sent to a separate speaker).
Dolby intro from their website:
Dolby Atmos Objects explained:
drive.google.com
Why was Atmos created?
The three competing Object Based audio systems were primarily created to add rich, realistic sound for movies. With Atmos an audio engineer can ensure a sound can follow an object on the screen, a helicopter circling overhead etc. Hundreds of movies are now available on Blu-ray and 4K UHD blu-ray with Atmos and DTS:X soundtracks. Many movie theaters have one of these systems installed.
Obviously, there are many surround music enthusiasts around the world. So the natural progression is to release Atmos music too. There are already several concerts and audio albums with Atmos mixes, with more coming.
Is Atmos backward compatible with existing equipment?
Atmos content does not require a new codec. It is implemented as an extension within the original Dolby TrueHD (lossless) and Dolby Digital Plus (lossy) codecs. Much like how DTS-HD was an extension to DTS.
Atmos can be delivered along with Dolby TrueHD, typically on blu-ray (BDV and BDA) at around 4000 to 7000kbps or along with Dolby Digital Plus, typically at 768kbps or less for streaming by Netflix, Apple, Tidal, Prime and similar services.
If your AVR does not have an Atmos decoder: If it has a Dolby TrueHD decoder it will decode the TrueHD 'core' to provide 5.1 or 7.1 channels (depending on your setup). In this situation you can playback an Atmos track, but its played back as 5.1 or 7.1 TrueHD. You will not hear the Atmos mix objects in their intended positions and will not hear any 3D immersion.
Although you need a new AVR to decode these Atmos extensions (older models will simply play the base TrueHD/Digital Plus content), Blu-ray players that fully conform to the Blu-ray specification will support
Atmos without requiring a firmware update.
Modern Media Players with HDMI will also playback Atmos tracks via HDMI pass-through to an Atmos, TrueHD or Dolby Digital Plus compatible AVR.
Do I lose anything by listening to an Atmos mix on a non-Atmos system in 5.1?
The raw musical information is sent to the 5.1 or 7.1 channels from the TrueHD or Dolby Digital Plus mix during Atmos track decoding, so you won't lose the base/core mix. However, the spatial information (location is 3D space) and will be ignored. You may not hear movement/panning or positioning as intended by the Atmos audio mixer but no music is lost.
Edit Sept 2020: Tests show if you have an Atmos decoder (AVR or BD Player), height channels get downmixed into front and/or side channels in a 5.1 system, so the height channels are reproduced in 5.1, merged with fixed floor channels. You don’t lose height information, just the height spacial/immersion experience.
Atmos playback on 5.1 system tests/results here:
www.quadraphonicquad.com
What is the minimum system requirement to hear a 'real' Atmos mix?
Requirements:
1. An AVR or Surround Processor that has a Dolby Atmos decoder. (All Atmos AVRs I've seen also have DTS:X decoders too. Many also include Auro 3D decoders)
2. A traditional 5.1 or 7.1 speaker layout PLUS at least 2 ceiling or height enabled speakers. Preferably 4.
3. Having enough amplifier channels to drive all the above speakers. Most Atmos AVRs will have 9 or more channels (The Denon AVR-8500 has independent 13 amplifiers).
4. A playback device (e.g. Blu-ray Player, PC or Media player) with HDMI output.
If your existing 5.1 AVR has analog inputs, its also possible to buy a new AVR with 11 or 13 channel pre-amp outs and use that to drive your old 5.1 AVR as an amp only, thus limiting the size/cost of the new AVR.
What are my Atmos Speaker Options?
Dolby Atmos Speaker Configuration Options for Home are listed below, but first, here's the Object audio naming convention:
Typical Object Speaker configurations:
1. Seating position
2. Left and right speakers*
3. Center speaker*
4. Subwoofer*
5. Left and right surround speakers*
6. Left and right top front overhead speakers
7. Left and right top rear overhead speakers
* Denotes traditional 5.1 floor speakers
In addition to the number of channels, there’s also two options for additional height speakers: Discrete in-ceiling/ceiling-mounted speakers or 'Dolby Atmos-enabled' speakers utilizing what they call 'reflective speaker technology':
1. Traditional speakers - Advantages: Better sound Disadvantages: Need to run new cabling within ceiling (and up walls)
2. Dolby patented 'Dolby Atmos Enabled' speakers. These are upward-firing drivers positioned on the front and/or rear speakers, they bounce the sound off the ceiling of your living room, giving the impression
that sounds are coming from above you. Advantages: Easier installation Disadvantages: Only suitable for Dolby Atmos, Sound is compromised vs traditional speakers
Typical Atmos Enabled/Upfiring system (from the Dolby website):
Typical Atmos system with ceiling speakers:
Do Atmos Enabled Speakers Really Work?
Here's an interesting article:
www.audioholics.com
What music is available in Atmos now?
There have been several Atmos music releases as of August 2019, both concerts and albums:
Notable Concerts on Blu-ray:
Imagine Dragons - Smoke & Mirrors Live
KISS - Kiss Rocks Vegas
Michael Schenker's Temple of Rock: On a Mission - Live in Madrid 4K
Mumford & Sons - Dust and Thunder
Roger Waters - The Wall
Notable Albums on Blu-ray:
Booka Shade - Galvany Street
INXS - Kick: 30th Anniversary Edition (includes some Music Videos in Atmos)
Kraftwerk - 3D The Catalogue (Includes Concert and Video in Atmos)
R.E.M. - Automatic For The People (25th Anniversary Edition)
Schiller - Morgenstund
The Beatles - Abbey Road (Sept. 2019 - 50th Anniversary Super Deluxe)
Here's the offical Dolby Atmos Music list (it's not a complete list):
www.dolby.com
What music will be available in Atmos soon?
Dolby have recently teamed up Universal Music Group and announced 'several hundred' songs will be mixed and released in Atmos (soon).
www.billboard.com
As of August 2019 it is unclear how the UMG Atmos songs will be distributed, although it seems there will be at least a streaming/download option. Expect more information soon.
Artists mentioned as of August 2019 in various press releases:
Beck, R.E.M. LL Cool J, Wu-Tang Clan, R.E.M., Marvin Gaye, Public Enemy and Snoh Aalegra.
The Beatles’ Sgt Pepper has been mixed in Dolby Atmos for theatrical release to celebrate the groundbreaking album’s 50th anniversary. And more recently David Gilmour returned to Abbey Road Studios in 2017 for an Atmos mix of his Pompeii Live In Concert. Both mentioned here:
Miles Davis’ - Kind of Blue mentioned here:
www.mixonline.com
INXS - Live Baby Live in 4K and Atmos for theatres here:
newmusicweekly.com
Atmos seems to be the market leader in object based audio, dominating the Movie space, there are also many DTS:X movies, Auro 3D has a few classical music only releases.
What about Atmos Upmixing stereo and quad music?
New AVRs with Atmos decoders also provide an onboard Atmos upmixer. This is more advanced than previous Dolby upmixer generations. The Atmos operates on stereo, quad, 5.1 and latest 7.1 Dolby TrueHD mix.
The system is capable of steering individual frequency bands from each channel to create up a matrixed Atmos environment based on your speaker configuration. Atmos upmixer will not send redirected content
to speakers between the front left, center, and right speakers in order to minimize the impact on the front stage.
These Atmos enables AVRs typically also do DTS Neural:X upmixing too.
Are there Atmos test files or Demos available?
Atmos Channel Test files in MKV format for the following:
5.1.2, 5.1.4, 7.1.2, 7.1.4 and 9.1.6
There is also a short Atmos demo from Dolby with an interesting couple of 3D graphics explaining the difference between 'conventional' 5.1 mixes and Object mixes)
Link: Atmos - Google Drive
The Kodi Wiki also has quite a few HD Audio samples, including Atmos/DTS:X:
Link: Samples - Official Kodi Wiki
Can I convert Atmos to FLAC to play in my car, on PC or Media Player?
FLAC is limited to 8 channels. It is possible to convert an Atmos track’s legacy TrueHD to 5.1 or 7.1 FLAC but this will not contain the Atmos extensions (height and spatial metadata) so it can never reproduce the true Atmos mix during playback. It will contain the music but in 2D plain only.
It is possible to copy the Atmos codec audio track (unconverted original) in its original container (m2ts for BDA) or into another container that supports TrueHD (MKV, MKA, MP4) to play back via HDMI Passthrough to an AVR for Atmos decoding. (Most content will have DRM so ripping/conversion software will be required, the usual suspects that support TrueHD will support Atmos).
There are no known Atmos decoders except for those within Atmos licensed AVRs and Surround Processors. So Atmos playback must always include HDMI from an external ‘player’ to bitstream to your Atmos AVR/Processor.
Atmos playback from a PC or Media Player is possible with HDMI bitstreaming using Kodi and Jriver software.
Playback of Atmos files in Kodi:
www.quadraphonicquad.com
More Reading?
www.audioxpress.com
www.soundonsound.com
DISCLAIMER: Fair use is claimed on all images and test files, as their purpose is only for the promotion of Dolby Atmos music, testing and technical evaluation for our members. QuadraphonicQuad is a non-profit, non-sponsored website.
LAST EDITED: 2020-9-19
Dolby Atmos is an Object Based audio surround system (similar to competing DTS:X and Auro 3D systems). Object based systems are a combination of raw audio channels and metadata that describes the spatial position (in 3D space) and other properties of audio objects. Atmos (and DTS:X & Auro) add height speakers to create a true 3D sound field (5.1 is a 2D sound field).
So Atmos objects are not always locked to a specific channel (speaker), for example, an object can be set to appear in a 'phantom position' (between speakers), or can appear to move between any speakers in the speaker array in any direction. Atmos supports up to 128 simultaneous independent audio objects in a mix.
Furthermore, the intended spatial position can be rendered fairly accurately regardless of the actual speaker positions based on the actual Atmos speaker setup during installation, which will include a microphone and software in the AVR to measure speaker distances and gain (volume). The actual individual amplifier output is created during playback based on a combination of encoded mix and the speaker configuration (installation). However, more speakers will provide a better resolution of sound movement.
Dolby Atmos for Home, as delivered on Blu-ray and streaming services, are limited to 16 amplifier channels (similar an 'old' system 15.1 - However, as stated above, unlike traditional multichannel audio systems each channel is not sent to a separate speaker).
Dolby intro from their website:
Dolby Atmos Objects explained:
Atmos Surround Objects.mkv
Why was Atmos created?
The three competing Object Based audio systems were primarily created to add rich, realistic sound for movies. With Atmos an audio engineer can ensure a sound can follow an object on the screen, a helicopter circling overhead etc. Hundreds of movies are now available on Blu-ray and 4K UHD blu-ray with Atmos and DTS:X soundtracks. Many movie theaters have one of these systems installed.
Obviously, there are many surround music enthusiasts around the world. So the natural progression is to release Atmos music too. There are already several concerts and audio albums with Atmos mixes, with more coming.
Is Atmos backward compatible with existing equipment?
Atmos content does not require a new codec. It is implemented as an extension within the original Dolby TrueHD (lossless) and Dolby Digital Plus (lossy) codecs. Much like how DTS-HD was an extension to DTS.
Atmos can be delivered along with Dolby TrueHD, typically on blu-ray (BDV and BDA) at around 4000 to 7000kbps or along with Dolby Digital Plus, typically at 768kbps or less for streaming by Netflix, Apple, Tidal, Prime and similar services.
If your AVR does not have an Atmos decoder: If it has a Dolby TrueHD decoder it will decode the TrueHD 'core' to provide 5.1 or 7.1 channels (depending on your setup). In this situation you can playback an Atmos track, but its played back as 5.1 or 7.1 TrueHD. You will not hear the Atmos mix objects in their intended positions and will not hear any 3D immersion.
Although you need a new AVR to decode these Atmos extensions (older models will simply play the base TrueHD/Digital Plus content), Blu-ray players that fully conform to the Blu-ray specification will support
Atmos without requiring a firmware update.
Modern Media Players with HDMI will also playback Atmos tracks via HDMI pass-through to an Atmos, TrueHD or Dolby Digital Plus compatible AVR.
Do I lose anything by listening to an Atmos mix on a non-Atmos system in 5.1?
The raw musical information is sent to the 5.1 or 7.1 channels from the TrueHD or Dolby Digital Plus mix during Atmos track decoding, so you won't lose the base/core mix. However, the spatial information (location is 3D space) and will be ignored. You may not hear movement/panning or positioning as intended by the Atmos audio mixer but no music is lost.
Edit Sept 2020: Tests show if you have an Atmos decoder (AVR or BD Player), height channels get downmixed into front and/or side channels in a 5.1 system, so the height channels are reproduced in 5.1, merged with fixed floor channels. You don’t lose height information, just the height spacial/immersion experience.
Atmos playback on 5.1 system tests/results here:
Atmos and TrueHD 7.1 playback on 5.1 systems - Tests, Results, questions, experiences
Hopefully we’ll get a definitive answer to what happens when users playback Atmos and TrueHD 7.1 mixes on non Atmos/7.1 surround systems (typically 5.1, maybe some Quad only system users too). I have a set of Dolby Atmos channel identification test files with encoding for: 5.1.2, 5.1.4, 7.1.2...
www.quadraphonicquad.com
What is the minimum system requirement to hear a 'real' Atmos mix?
Requirements:
1. An AVR or Surround Processor that has a Dolby Atmos decoder. (All Atmos AVRs I've seen also have DTS:X decoders too. Many also include Auro 3D decoders)
2. A traditional 5.1 or 7.1 speaker layout PLUS at least 2 ceiling or height enabled speakers. Preferably 4.
3. Having enough amplifier channels to drive all the above speakers. Most Atmos AVRs will have 9 or more channels (The Denon AVR-8500 has independent 13 amplifiers).
4. A playback device (e.g. Blu-ray Player, PC or Media player) with HDMI output.
If your existing 5.1 AVR has analog inputs, its also possible to buy a new AVR with 11 or 13 channel pre-amp outs and use that to drive your old 5.1 AVR as an amp only, thus limiting the size/cost of the new AVR.
What are my Atmos Speaker Options?
Dolby Atmos Speaker Configuration Options for Home are listed below, but first, here's the Object audio naming convention:
Typical Object Speaker configurations:
- 5.1.2: A standard 5.1 setup with a pair of “middle” in-ceiling/ceiling-mounted speakers.
- 5.1.4: A standard 5.1 setup with a front and rear pairs of in-ceiling/ceiling-mounted speakers.
- 7.1.2: A standard 7.1 setup with a pair of “middle” in-ceiling/ceiling-mounted speakers.
- 7.1.4: A standard 7.1 setup with a front and rear pairs of in-ceiling/ceiling-mounted speakers.
- 9.1.2: A 9.1 setup utilizing front wide channels and a pair of “middle” in-ceiling/ceiling-mounted speakers.
1. Seating position
2. Left and right speakers*
3. Center speaker*
4. Subwoofer*
5. Left and right surround speakers*
6. Left and right top front overhead speakers
7. Left and right top rear overhead speakers
* Denotes traditional 5.1 floor speakers
In addition to the number of channels, there’s also two options for additional height speakers: Discrete in-ceiling/ceiling-mounted speakers or 'Dolby Atmos-enabled' speakers utilizing what they call 'reflective speaker technology':
1. Traditional speakers - Advantages: Better sound Disadvantages: Need to run new cabling within ceiling (and up walls)
2. Dolby patented 'Dolby Atmos Enabled' speakers. These are upward-firing drivers positioned on the front and/or rear speakers, they bounce the sound off the ceiling of your living room, giving the impression
that sounds are coming from above you. Advantages: Easier installation Disadvantages: Only suitable for Dolby Atmos, Sound is compromised vs traditional speakers
Typical Atmos Enabled/Upfiring system (from the Dolby website):
Typical Atmos system with ceiling speakers:
Do Atmos Enabled Speakers Really Work?
Here's an interesting article:
FAQ: Do Atmos Enabled Speakers Really Work?
We frequently get asked if Dolby Atmos add-on speaker modules work well enough to be a viable alternative to discrete ceiling mounted speakers. We answer and discuss the trade-offs to let you decide.
www.audioholics.com
What music is available in Atmos now?
There have been several Atmos music releases as of August 2019, both concerts and albums:
Notable Concerts on Blu-ray:
Imagine Dragons - Smoke & Mirrors Live
KISS - Kiss Rocks Vegas
Michael Schenker's Temple of Rock: On a Mission - Live in Madrid 4K
Mumford & Sons - Dust and Thunder
Roger Waters - The Wall
Notable Albums on Blu-ray:
Booka Shade - Galvany Street
INXS - Kick: 30th Anniversary Edition (includes some Music Videos in Atmos)
Kraftwerk - 3D The Catalogue (Includes Concert and Video in Atmos)
R.E.M. - Automatic For The People (25th Anniversary Edition)
Schiller - Morgenstund
The Beatles - Abbey Road (Sept. 2019 - 50th Anniversary Super Deluxe)
Here's the offical Dolby Atmos Music list (it's not a complete list):
Music Reborn in Dolby | Dolby Atmos Music
Dolby Atmos Music reinvents how songs are made and experienced.
www.dolby.com
What music will be available in Atmos soon?
Dolby have recently teamed up Universal Music Group and announced 'several hundred' songs will be mixed and released in Atmos (soon).
Universal Music Group Looks to the Future of Sound Mixing With Dolby Atmos
Universal Music Group (UMG) and Dolby Laboratories are teaming up to bring Dolby’s cutting-edge Atmos immersive audio technology to the world of music, the companies announced on Thursday (May 23).
As of August 2019 it is unclear how the UMG Atmos songs will be distributed, although it seems there will be at least a streaming/download option. Expect more information soon.
Artists mentioned as of August 2019 in various press releases:
Beck, R.E.M. LL Cool J, Wu-Tang Clan, R.E.M., Marvin Gaye, Public Enemy and Snoh Aalegra.
The Beatles’ Sgt Pepper has been mixed in Dolby Atmos for theatrical release to celebrate the groundbreaking album’s 50th anniversary. And more recently David Gilmour returned to Abbey Road Studios in 2017 for an Atmos mix of his Pompeii Live In Concert. Both mentioned here:
Miles Davis’ - Kind of Blue mentioned here:
PMC Demonstrates Unreleased Dolby Atmos Music At HIGH END Munich 2019 - Mixonline
UK loudspeaker manufacturer PMC has deployed its unprecedented access to leading artists, studios and record labels to give visitors at the HIGH END Munich HiFi show a unique demonstration of Dolby Atmos music, the leading immersive audio solution adopted by the audio and music mixing...
www.mixonline.com
INXS - Live Baby Live in 4K and Atmos for theatres here:
INXS' Wembley Concert To Hit Movie Theatres - New Music Weekly
New Music Weekly is the music industry leading trade publication servicing the radio industry. Focusing on both major and indpendent music at radio, New Music Weekly provide the music and radio industry with 24/7 radio airplay tracking and chart data via SpinsTrackingSystem (STS).
newmusicweekly.com
Atmos seems to be the market leader in object based audio, dominating the Movie space, there are also many DTS:X movies, Auro 3D has a few classical music only releases.
What about Atmos Upmixing stereo and quad music?
New AVRs with Atmos decoders also provide an onboard Atmos upmixer. This is more advanced than previous Dolby upmixer generations. The Atmos operates on stereo, quad, 5.1 and latest 7.1 Dolby TrueHD mix.
The system is capable of steering individual frequency bands from each channel to create up a matrixed Atmos environment based on your speaker configuration. Atmos upmixer will not send redirected content
to speakers between the front left, center, and right speakers in order to minimize the impact on the front stage.
These Atmos enables AVRs typically also do DTS Neural:X upmixing too.
Are there Atmos test files or Demos available?
Atmos Channel Test files in MKV format for the following:
5.1.2, 5.1.4, 7.1.2, 7.1.4 and 9.1.6
There is also a short Atmos demo from Dolby with an interesting couple of 3D graphics explaining the difference between 'conventional' 5.1 mixes and Object mixes)
Link: Atmos - Google Drive
The Kodi Wiki also has quite a few HD Audio samples, including Atmos/DTS:X:
Link: Samples - Official Kodi Wiki
Can I convert Atmos to FLAC to play in my car, on PC or Media Player?
FLAC is limited to 8 channels. It is possible to convert an Atmos track’s legacy TrueHD to 5.1 or 7.1 FLAC but this will not contain the Atmos extensions (height and spatial metadata) so it can never reproduce the true Atmos mix during playback. It will contain the music but in 2D plain only.
It is possible to copy the Atmos codec audio track (unconverted original) in its original container (m2ts for BDA) or into another container that supports TrueHD (MKV, MKA, MP4) to play back via HDMI Passthrough to an AVR for Atmos decoding. (Most content will have DRM so ripping/conversion software will be required, the usual suspects that support TrueHD will support Atmos).
There are no known Atmos decoders except for those within Atmos licensed AVRs and Surround Processors. So Atmos playback must always include HDMI from an external ‘player’ to bitstream to your Atmos AVR/Processor.
Atmos playback from a PC or Media Player is possible with HDMI bitstreaming using Kodi and Jriver software.
Playback of Atmos files in Kodi:
Kodi: Adding support for Atmos, TrueHD and DTS:X, DTS-HDMA audio only files
If you want to add music only files containing the above codecs to the Kodi Music Library, I recently found a way to do so. Previously I always converted to FLAC as 5.1 (or 7.1 if the original music was in 7.1 format). Kodi has no issue playing MCH flac up to 7.1. But now I have an Atmos...
www.quadraphonicquad.com
More Reading?
Object-Based Audio and Sound Reproduction
Object-Based Audio. You’ve heard the term. It means we no longer need to record audio information in 6 (5.1), 8 (7.1), or an insane number of audio channels – 22.2, as Japan is pitching for its 8K production and broadcast standard – to properly convey the spatial information of sound...
Dolby Atmos At The Ministry Of Sound
Dolby Laboratories have been leading the development of surround-sound systems for four decades, but over the last year or so they have been piloting an intriguing surround system in a famous UK night-club...
DISCLAIMER: Fair use is claimed on all images and test files, as their purpose is only for the promotion of Dolby Atmos music, testing and technical evaluation for our members. QuadraphonicQuad is a non-profit, non-sponsored website.
LAST EDITED: 2020-9-19
Last edited:
