Simple Atmos Music Questions

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ssully

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The promotional material about Atmos is such gobbledygook, I thought you guys could clear things up way faster for me. These questions concern Dolby Atmos surround music offerings (for now):

1. Suppose you have an Atmos ready AVR (in my case, a Denon X3300W) , and a 5.x system (where x is subwoofers, not more loudspeakers) . If you play Atmos surround content, what happens? Does an Atmos-ready AVR downmix Atmos content to 5.x?

2. What is the connection chain for a music-centered Atmos setup? Atmos source/app --> Atmos-ready AVR --> TV + speakers? Atmos source/app-->Tv-->AVR--> Speakers?

3. Is there any way to tell, e.g. from metadata, that an 'Atmos' music selection was actually remixed, versus upmixed?
 
1. Suppose you have an Atmos ready AVR (in my case, a Denon X3300W) , and a 5.x system (where x is subwoofers, not more loudspeakers) . If you play Atmos surround content, what happens? Does an Atmos-ready AVR downmix Atmos content to 5.x?

From the Atmos FAQ here on QQ:

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 640kbps or less for streaming by Netflix, Itunes, Prime, Soundcloud 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.

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 spacial information (location is 3D space) and possibly height Audio will be lost. You may not hear movement/panning or positioning as intended by the Atmos audio mixer.
 
But as I wrote, my AVR *does* have an Atmos decoder. But my speaker configuration is not Atmos. Can I assume it will be smart enough to just decode the TrueHD core? And what is the TrueHD "base/core" mix for the new Atmos mixed sound files? Is it an upmix of the stereo, a downmix of "the Atmos mix", the Atmos mix minus its height channel content, or something else?
 
But as I wrote, my AVR *does* have an Atmos decoder. But my speaker configuration is not Atmos. Can I assume it will be smart enough to just decode the TrueHD core? And what is the TrueHD "base/core" mix for the new Atmos mixed sound files? Is it an upmix of the stereo, a downmix of "the Atmos mix", the Atmos mix minus its height channel content, or something else?

The Atmos algorithm is designed to detect a setup of speakers configured in any amount from 2.0 to 11.1.4

The algorithm will then "downmix" it is never an upmix to the speaker configuration...
So example of a 7.1 system. 11.1.4--> becomes 7.1
Example of a soundbar: 11.1.4--> becomes 2.0
 
It's my understanding that Atmos is speaker-configuration agnostic - so if you have an Atmos-capable device, you get Atmos at anywhere from 2.0 (ie headphones) up to 11.2.4, with the mix rendered to fit your specific configuration.

If you have an Atmos enabled AVR and "only" a 5.1 speaker setup, you should still be getting a 5.1 rendering of the Atmos stream - the only time you'd be getting the 5.1/7.1 "core" is with an older AVR that supports Dolby TrueHD but not Atmos.

I think the providers like Tidal who stream Atmos are a different kettle of fish though - while the above is always true, I believe that for Atmos music, the Tidal app (like the Netflix app) will only enable Atmos playback if your setup (ie streaming device, AVR and TV) is fully HDMI 2.0/HDCP 2.2 compliant - otherwise you get standard 2.0 stereo. I don't know if there's any eventuality where you'd actually be listening to a 5.1/7.1 DD+ "core", it seems like it's either Atmos or 2.0 and nothing in between.
 
Yes, I think the Tidal app attempts an Atmos handshake with the audio device. If no Atmos then it plays a stereo file, it doesn’t even stream the Atmos version. (Of course I maybe wrong)
 
I have both Amazon Music HD and the latest Tidal update with Atmos capability residing on my NUC (Windows 10) - which has Dolbty Atmos Home Theater capability. My speaker set-up is 5.1 and my receiver, which connects to my NUC via HDMI, can only decode Dolby Tru HD. When playing Tidal Atmos tracks my receiver indicates Tru HD but renders no sound. I have to change the soundcard settings to 2.0 to hear anything. Amazon 3D content is not recognized as Dobly Tru HD and again, will only render a 2.0 signal.

This is all early days, and I am loathe to invest in new gear. I can wait till this gets sorted out. Been burned too many times before - I still have my Toshiba HD DVD player;)
 
Yes, I think the Tidal app attempts an Atmos handshake with the audio device. It no Atmos then it plays a stereo file, it doesn’t even stream the Atmos version. (Of course I maybe wrong)

You’re not wrong. On Apple TV 4K, upon first use of the Tidal app you get the message “Your configuration supports Dolby Atmos.” It then offers Atmos albums and playlists, with each track labelled with a Dolby logo. If I run Tidal on my older, non-4K Apple TV, I get no message nor any offerings of Atmos tracks. They all disappear.

Haven’t tested “tricking” my 4K Apple by setting it to lower resolution and audio, but my guess is it would have the same effect as using the older hardware.
 
Yes, I think the Tidal app attempts an Atmos handshake with the audio device. It no Atmos then it plays a stereo file, it doesn’t even stream the Atmos version. (Of course I maybe wrong)

This was my experience earlier this morning with Tidal on a Firestick 4K, along with a message about lack of Atmos compatibility. It then played the song in 2.0 DD+.
 
DSU is for two channel while Atmos and downmixing to 7.1/5.1 is a different animal, no?
Yeah, 2 different things but still looks like Dolby are taking away functionality. I understand why companies do this sort of thing ($) but removing functionality means something's less of a Swiss Army knife which annoys customers (those with the $).
 
1. Suppose you have an Atmos ready AVR (in my case, a Denon X3300W) , and a 5.x system (where x is subwoofers, not more loudspeakers) . If you play Atmos surround content, what happens? Does an Atmos-ready AVR downmix Atmos content to 5.x?

May have been already answered but I can tell you for sure that you must have a couple of speakers connected to the 'Surround Back' connections on your Denon and then configure them for one of the Atmos speaker possibilities covered in the manual for the receiver to 'see' an Atmos signal and switch to that mode. I have an X3200.
 
This all seems rather bad news. DSU -- with center spread -- was already inferior (to my ears) to the more user-configurable DPLII Music as a 2ch upmixer. And the Atmos story still seems a mess.

But I'm still curious about this:


If you have an Atmos enabled AVR and "only" a 5.1 speaker setup, you should still be getting a 5.1 rendering of the Atmos stream - the only time you'd be getting the 5.1/7.1 "core" is with an older AVR that supports Dolby TrueHD but not Atmos.


Assuming this even happens, what exactly is the 5.1/7/1 'core' compared to the '5. rendering of the Atmos stream'? And how is it created? (This seems a quite different concept from the e.g. DTS 'core' which is , in the case of DTS 96/24, basically the same mix without the ultrasonic content. Not a different mix configuration per se)
 
But I'm still curious about this:

steelydave said:
"If you have an Atmos enabled AVR and "only" a 5.1 speaker setup, you should still be getting a 5.1 rendering of the Atmos stream - the only time you'd be getting the 5.1/7.1 "core" is with an older AVR that supports Dolby TrueHD but not Atmos."

Assuming this even happens, what exactly is the 5.1/7/1 'core' compared to the '5. rendering of the Atmos stream'? And how is it created? (This seems a quite different concept from the e.g. DTS 'core' which is , in the case of DTS 96/24, basically the same mix without the ultrasonic content. Not a different mix configuration per se)

Atmos will detect your speaker set up based on how many you have told your AVR you have. So for example, I have 7.1 setup. When I play Atmos mixes, the traditional 4 overhead channels (the .4 of 7.1.4) are mixed back into the 7 channels. So I am hearing 7 of 11 discrete channels of music. But it is the "Atmos mix" it's just being re-channel into the 7 existing speakers.
 
dts algorithms for psuedo-surround are pretty decent

I disagree. The original dts Neo did not even modify the front channels at all, simply adding extracted info to the rears, This obviously is not any kind of real surround, but also changes the track’s overall content and balance. Not for me.
 
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