Atmos Playback In 5.1

[kfbkfb]

(try the coaxial digital audio output for a 5. 1 mix)

Is there a movie or audio [UHD] Blu-ray with Atmos test signals which can be used to check and see where the the Atmos signals are mapped for 5.1 (either by the AV receiver or the preset DD 5.1 downmix done at disc authoring time)?


https://spearsandmunsil.com/products/
Maybe this disc has suitable Atmos test signals, anyone have this disc (I plan to buy one soon).


Kirk Bayne

 

[sjcorne]

So how about it @sjcorne, can you do the above test? You're the one who goes on about your access to the Dolby Renderer and what it does.

The obnoxious tone really isn't necessary.

I don't have the ADM masters for the DSOTM Atmos mix (presumably only James Guthrie has those?), so I can't play it through the Dolby Renderer.

However, I can put the TrueHD files into the Dolby Reference Player and view the results through a variety of different speaker mappings.

In 7.1.4, everything seems to be coming from the proper location:

However, in both 7.1 & 5.1 - as you say - the height channels appear to be mapped incorrectly:

The only other Atmos channel test I have (from ImmersiveAudioAlbum.com) places the height information correctly in 5.1, so I'm not sure what happened on this PF disc - but that is 100% not how Atmos is supposed to map to smaller arrays, a mistake was made somewhere in the process of creating this channel test.

If you were to play literally any other Atmos Blu-Ray on your 5.1 setup, I'm sure the front height information would come exclusively from the front left & right speakers as intended.

 

[sjcorne]

Dolby Labs' channel ID tests on Apple Music are another great way to check how Atmos content plays on your system:

 

[Owen Smith]

The obnoxious tone really isn't necessary.

It wasn't intended to be obnoxious, it's just you've rubbished everything I've said on the subject including my statements about this Pink Floyd disc. Your tests (thanks for running them) prove on this occasion that what I said is entirely correct.

The only other Atmos channel test I have (from ImmersiveAudioAlbum.com) places the height information correctly in 5.1, so I'm not sure what happened on this PF disc - but that is 100% not how Atmos is supposed to map to smaller arrays, a mistake was made somewhere in the process of creating this channel test.

I'm pretty sure the same thing has been done to the Atmos album. When I played it with Atmos decode engaged (which corrected the channel IDs on my 5.0 setup), the music certainly sounded more discrete. Clear examples are the ticking clocks and alarms section or the start of Money with the tills noises, in both cases it's fairly easy to hear where each sound is.

From what I've understood reading various posts, how the Atmos channels are mixed into the 7.1 bed is not fixed but is a choice by the mixing engineer. In this case I think they're trying to fake up where the height channels would be using the other channels. And on a 7.x system it might work depending on the room and speaker positions. The problem on a 5.x system is the front heights play something out of the rear speakers and that just wrecks things.

 

[Owen Smith]

The problem with the IAA Dolby Atmos + Surround Channel Test | IAA test tracks is they want me to enter a load of information about myself just to download something that is free. I don't want to do that. I also have no means of playing Apple Music tracks at the moment. But the information is good to have, it should help plenty of people.

What I want is a blu ray with Atmos channel IDs rendered in the more typical manner. Or at least a free download that doesn't require a ton of information about me to be entered.

 

[sjcorne]

It wasn't intended to be obnoxious, it's just you've rubbished everything I've said on the subject including my statements about this Pink Floyd disc.

In post #6, you made a blanket statement that Atmos playback in 5.1 "spread(s) the heights out and hinder(s) the discrete-ness." In post #8, I provided evidence to the contrary - the VU meters in those images clearly indicate that the audio information meant for the front heights played exclusively in the front left & right channels when the audio output was set to 5.1.

I'm not sure how that qualifies as 'rubbishing' everything you said, though I realize now your comments were based off the Atmos channel ID test on the DSOTM BD (which I think we've established provides inaccurate results - again, I have no idea how they screwed this up).

I found another set of Atmos channel ID files posted here (thank you @HomerJAU!) and I'm getting correct results from those in 5.1 & 7.1 as well. Front heights only in fronts, rear heights only in rears.

 

[Owen Smith]

I found another set of Atmos channel ID files posted here (thank you @HomerJAU!) and I'm getting correct results from those in 5.1 & 7.1 as well. Front heights only in fronts, rear heights only in rears.

The post that link goes to has no files in.

 

[Owen Smith]

though I realize now your comments were based off the Atmos channel ID test on the DSOTM BD

Correct. It's the only Atmos channel ID test I have. They appear to be uncommon based on other people searching for some test files.

(which I think we've established provides inaccurate results - again, I have no idea how they screwed this up).

It's not clear to me this is a mistake, I think it's intentional. While Dolby may have preferred locations for the height channels in the 7.1 bed, there is nothing to stop mixers putting them elsewhere as we have discovered. And the Atmos itself still decodes correctly, so while it's different and it produces poor results on a 5.x system it may be a deliberate decision.

 

[HomerJAU]

The post that link goes to has no files in.

The first post in that thread has valid links

 

[The Pink Floyd]

I don't know enough about Atmos so I need to ask this. If a recording comes out in Atmos only, does it down scale to 5.1 if you don't have Atmos?

 

[LuvMyQuad]

I don't know enough about Atmos so I need to ask this. If a recording comes out in Atmos only, does it down scale to 5.1 if you don't have Atmos?

Yes

 

[jsulzinger]

I don't know enough about Atmos so I need to ask this. If a recording comes out in Atmos only, does it down scale to 5.1 if you don't have Atmos?

It depends on your player setup, receiver setup and the disc. Most Atmos releases downmix and sound great on my basic Oppo/Yamaha 5.1 system. A few output weird results that are unlistenable.

 

[inspclouseau]

Generally, 'downmixed' to '5.1' sounds like sht. Music streaming rentals and dolby are destroying physical. As designed.

 

[Sal1950]

Generally, 'downmixed' to '5.1' sounds like sht. Music streaming rentals and dolby are destroying physical. As designed.

I strongly disagree with your statement that they "sound like sht".

I do agree that streaming is destroying physical media, but I don't see where you can fold "Dolby" into that situation.
But like vinyl, there will always be a small niche market to support enthusiasts like us. I hope.

 

[LuvMyQuad]

Generally, 'downmixed' to '5.1' sounds like sht. Music streaming rentals and dolby are destroying physical. As designed.

I disagree with this as well.

First, there is no downmix from Atmos to 5.1. Atmos on disc has a 7.1 bed with all the Atmos signal contained within it. If you play it on a 7.1 system, all the information is there. If you play it on an Atmos system it separates out the height info and directs it to the height speakers.

The "downmix" is from 7.1 to 5.1. Out of necessity the process will place various sounds in different channels. It has to in order to account for less channels.

In my experience Atmos played back on a 5.1 system sounds quite good. I've never had an experience where it sounds like shit. In fact, if you aren't a fan of gimmicky effects coming through on the heights, you may prefer it.

 

[Mr. Afternoon]

Generally, 'downmixed' to '5.1' sounds like sht. Music streaming rentals and dolby are destroying physical. As designed.

This is a very tricky statement.

For the first bit, most of the time it does NOT sound bad downmixed...there are some oddities in some mixes where you can hear something is slightly off because it's been designed for a full Atmos rig but nothing TOO bad.

For the second bit...yeah. I can absolutely share some sentiment there. Not to say there haven't been benefits to Atmos streaming, but...

 

[inspclouseau]

This is a very tricky statement.

For the first bit, most of the time it does NOT sound bad downmixed...there are some oddities in some mixes where you can hear something is slightly off because it's been designed for a full Atmos rig but nothing TOO bad.

For the second bit...yeah. I can absolutely share some sentiment there. Not to say there haven't been benefits to Atmos streaming, but...

When I can compare a 5.1 DTS MA to an Atmo version of same ('folded'' to 5.1)s ....make no mistake, it sounds like crap compared to the DTS 5.1 version on same titles. At least the ones we own. DTS has been squeezed out now, almost completely and so have we..... Nothing 'tricky' at all. Just the simple truth.

 

[inspclouseau]

I strongly disagree with your statement that they "sound like sht".

I do agree that streaming is destroying physical media, but I don't see where you can fold "Dolby" into that situation.
But like vinyl, there will always be a small niche market to support enthusiasts like us. I hope.

yup..we have opinions. My ears are mine Yes..Dolby Atmos was most likely designed for streaming.. Isn't that obvious?

 

[sjcorne]

When I can compare a 5.1 DTS MA to an Atmo version of same ('folded'' to 5.1)s ....make no mistake, it sounds like crap compared to the DTS 5.1 version on same titles. At least the ones we own.

...and those titles are?

Dolby Atmos was most likely designed for streaming.. Isn't that obvious?

Obviously false, perhaps?

 

[JediJoker]

Dolby Atmos was most likely designed for streaming.. Isn't that obvious?

No, not at all. Atmos was obviously designed for cinemas. Music and streaming were afterthoughts.