Why is everyone so jazzed about ATMOS?

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himey

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if there is content in the overheads, and the program material is played on a non-ATMOS surround system (like DTS), the overhead stuff is just gone. If it's played on an ATMOS system that has no overhead speakers (5.1 or 7.1 for instance), Dolby 'figures out' where to put the overhead content to best represent the overhead material.
That isn't my understanding. Where do you think the audio is stored that gets redirected to the heights?
 

fredblue

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ah thanks! Unfortunately there's only one project that's currently in distribution. Another coming in October, several more in the next 6 months. If you use Apple Music, David Ramirez's Rules and Regulations is up now. It's a bit unusual; the stereo version was recorded and mixed live at my place - directly off the board, no mastering/post applied. Just wanted the sound I heard in the control room as the band was playing. I cut the vinyl master and a short run was pressed. We also did 2 songs live-to-disc that are now on a 7", which is not available anywhere as far as I know. All this is very non-surround! But we saved all the original tracks and did ATMOS mixes of each song on the EP. This was really quite challenging, as there was a huge amount of bleed - for instance, one of the main contributors to the drum sound in the live stereo recording was from the lead vocal mic. Placing things in a 3D field sometimes was challenging. Anyway, it was our first full-project ATMOS mixed on the new monitoring system in the studio, and it is what it is. If interested you can see the stereo versions being recorded here:

This is probably too much information, but it's kind of a different project, and maybe someone will find it interesting. Or not. Also, if it violates and forum policy, apologies and feel free to delete!

nice one! thank you!

here it is on Apple Music 🤩

 

J. PUPSTER

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This is probably too much information, but it's kind of a different project, and maybe someone will find it interesting. Or not. Also, if it violates and forum policy, apologies and feel free to delete!
Welcome into the QQ, thanks for the detailed info, we love that kind of info here!!!

Best of luck going forward on your Atmos journey.
 
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Are you sure? If you connect an Apple TV to a non-Atmos AVR via HDMI, the Atmos tracks on Apple Music will be internally decoded to 5.1 PCM with the front height content redirected to the front speakers and the rear height & side content sent to the rears. It's very easy to confirm this using the Dolby Labs test tones on Apple Music. That said, some albums seem to downmix much better than others.
I don't believe this is true with discreet objects placed up high....at least that's what the belief is among the audio engineers I communicate with. For audio in the bed that's raised higher in the field, it does seem to translate the way you describe.
 
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That is not true. First off, there is no way to play Atmos on a DTS system. Atmos is a Dolby system. In its raw, undecoded state, and Atmos track is encoded as 7.1 Dolby True HD. All the height info is embedded in the 7.1 channels. The embedded metadata directs the decoder where to put it. With no decoder it simply stays in the 7.1 channel array.

EDIT: My reply only applies to playback via AVRs ans AVPs. I cant speak for anything PC based.
 
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Ah yes....but if playing Apple Music 'ATMOS' tracks on Apple TV thru my old Denon DTS rig, I get 5.1. In those cases the overhead stuff, particularly the content defined as small, discrete objects placed way up high seem to disappear. So, I guess this is really an Apple thing, as Apple decodes to 5.1 without any of the ATMOS intelligence if the target is a non-ATMOS capable device? All this being said, a lot of strange things seem happen in the Apple/Spatial/Dolby world. I've had trouble QC'ing mixes before release for the Apple/AVR consumer environment. I can play mixes in Dolby ADM/BWF form across multiple ATMOS mix rooms with no problem. It's easy to see any translation differences. Comparing the binaural and Apple Spatial renders is weird by seems stable now. But playing a pre-released mix via an AVR from Apple TV requires an mp4 render from the Dolby ATMOS Renderer, and I've had some weird results there.
 

himey

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I don't believe this is true with discreet objects placed up high....at least that's what the belief is among the audio engineers I communicate with. For audio in the bed that's raised higher in the field, it does seem to translate the way you describe.
Check out the posts made by sdurani over at avs forum. He will help you to understand exactly what is going on when the metadata is read by the processor, and when it isn't.

Again, where do you think the objects audio is stored? Some hidden channel? Do they magically appear out of nowhere? They are in the bed, not some hidden track with all the object sounds.
 

halbroome

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fredblue

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Add the producter of Radiohead to the "Just say no to Atmos" critics. Of course, he praises Kubrick for using mono on all his films!

Kubrick was a Master Filmmaker, absolutely no denying that.

however, i find it rather bizarre how some folk can't move on creatively and instead get stuck in a kind of revisionist mode.. intransigent... and seem to hold the view that just because things worked one way years ago somehow automatically infers there's no other way to do things thereafter?! 🤷🏻‍♀️🤦‍♀️
 
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Check out the posts made by sdurani over at avs forum. He will help you to understand exactly what is going on when the metadata is read by the processor, and when it isn't.

Again, where do you think the objects audio is stored? Some hidden channel? Do they magically appear out of nowhere? They are in the bed, not some hidden track with all the object sounds.
I'm not sure what you mean by where audio is 'stored'? When mixing, there's the bed, and there are objects. They are different things. You can pan tracks in the mix session around in the bed, both horizontally and vertically. Or you can define the track as an object, which gives you a much more defined placement in the 3D field. And the object's size (visualized as a sphere in the various DAW's) can be adjusted from a very discreet point a larger more diffuse object. When you mix, you can put effects like compression / limiting on the bed, but the objects won't be affected - they are completely separate get a different treatment if needed. There is a lot written about use of objects and beds, and tradeoffs for audio results in different environments. Broadcast, cinema, music, etc. Way beyond my pay-grade to explain all of that. And, there's a lot written about what happens to your ADM/BWF (Atmos master) is delivered to distribution. Binaural headphone versions non-Apple streaming. For Apple Music - the 7.1.4 master I create gets downmixed to 5.1.4 for creation of the Apple Spatial headphone mix....which is NOT the same as the binaural headphone version. I find this bizarre, but i'm sure there's a reason for it. Apple music sends 5.1 non-ATMOS devices. And truly, the Apple stuff can change at any time, for no reason. Firmware for Airpods, new releases in the operating system (s), etc. can change what you hear from one day to another.

Now Himey - to your point. That 5.1 that Apple is sending to an AVR is created from the original ADM/BWF that I sent to distribution. So, all the height information that I mixed should be contemplated when that downmix is created, so the overhead stuff should show up somewhere. But sometimes, it doesn't show up when played back through non-ATMOS surround. I fooled around testing in my rooms (mix room and home theater) a year or so ago - my assumption was that it was objects that may have been missing up high.

But I may be wrong, for sure. As my wife says, 'you have lots of opinions, but it doesn't mean you're right!'

I've given up trying to the why's of it all, and I've settled on a workflow that I can live with. When mixing I toggle monitoring constantly between 7.1.4 and Apple Spatial with Airpods. I can spend several hours on a mix, monitoring with only in 7.1.4, and the Spatial sounds really bad. Or the other way around. So I just bounce constantly between 7.1.4 and Spatial. At the end of the day, I'll check 5.1. and 7.1. Maybe 5.1.2. Usually no problem there....I'll also check the non-Apple Binaural mix. There can definitely be some weirdness there as compared to Apple Spatial, so it's good to check and adjust if need be. I'm careful about how much overhead stuff I use - And that's pretty much it. I just don't have the time or inclination any more to check non-ATMOS playback any more. So, if there's loss of height information, so be it.
 

himey

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I'm not sure what you mean by where audio is 'stored'? When mixing, there's the bed, and there are objects. They are different things. You can pan tracks in the mix session around in the bed, both horizontally and vertically. Or you can define the track as an object, which gives you a much more defined placement in the 3D field. And the object's size (visualized as a sphere in the various DAW's) can be adjusted from a very discreet point a larger more diffuse object. When you mix, you can put effects like compression / limiting on the bed, but the objects won't be affected - they are completely separate get a different treatment if needed. There is a lot written about use of objects and beds, and tradeoffs for audio results in different environments. Broadcast, cinema, music, etc. Way beyond my pay-grade to explain all of that. And, there's a lot written about what happens to your ADM/BWF (Atmos master) is delivered to distribution. Binaural headphone versions non-Apple streaming. For Apple Music - the 7.1.4 master I create gets downmixed to 5.1.4 for creation of the Apple Spatial headphone mix....which is NOT the same as the binaural headphone version. I find this bizarre, but i'm sure there's a reason for it. Apple music sends 5.1 non-ATMOS devices. And truly, the Apple stuff can change at any time, for no reason. Firmware for Airpods, new releases in the operating system (s), etc. can change what you hear from one day to another.

Now Himey - to your point. That 5.1 that Apple is sending to an AVR is created from the original ADM/BWF that I sent to distribution. So, all the height information that I mixed should be contemplated when that downmix is created, so the overhead stuff should show up somewhere. But sometimes, it doesn't show up when played back through non-ATMOS surround. I fooled around testing in my rooms (mix room and home theater) a year or so ago - my assumption was that it was objects that may have been missing up high.

But I may be wrong, for sure. As my wife says, 'you have lots of opinions, but it doesn't mean you're right!'

I've given up trying to the why's of it all, and I've settled on a workflow that I can live with. When mixing I toggle monitoring constantly between 7.1.4 and Apple Spatial with Airpods. I can spend several hours on a mix, monitoring with only in 7.1.4, and the Spatial sounds really bad. Or the other way around. So I just bounce constantly between 7.1.4 and Spatial. At the end of the day, I'll check 5.1. and 7.1. Maybe 5.1.2. Usually no problem there....I'll also check the non-Apple Binaural mix. There can definitely be some weirdness there as compared to Apple Spatial, so it's good to check and adjust if need be. I'm careful about how much overhead stuff I use - And that's pretty much it. I just don't have the time or inclination any more to check non-ATMOS playback any more. So, if there's loss of height information, so be it.
I never made a distinction between Atmos and Apple Atmos. Someone else may have.

When I mean storage, I simply a mean in the Dolby True HD stream. The sounds, bed or objects must reside within the confinement of the format. I can't imagine where the object sounds could be stored separate from the 7.1 channels.

You bring up a great point about the streaming Atmos implementation. Not only is it lossy, unlike the 7.1 + metadata for Blu-ray, it is 5.1 + metadata. When you say "But sometimes, it doesn't show up when played back through non-ATMOS surround" I wonder if the process from going 7.1 to 5.1 may have a problem? The "Atmos Master" before going to distribution is an interesting topic.


Just because you have control of the bed sounds and the object sounds separately, within the Atmos mix session, shouldn't necessarily mean they are kept separate when they are rendered to the constraints of the Dolby TrueHD format. My understanding, with a typical Blu-ray release, all the sounds are within the 7.1 channels and the metadata moves them to the heights, and silences them in the bed through a complicated process.
 

boondocks

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@austinsignal & @himey good discussion here, and I'm learning things.

I used the Dolby Media Encoder for only the 4th time today. Today was to encode an 8 channel file I mixed from extracted stems (with edits).
That was simple enough, although initially the encoding process seemed complicated.
Baby steps. Friends with more knowledge.

I have a 5.1.2 system so only two overhead speakers.
But now I'm ready to start diving deeper, to at least learn the capabilities of mixing for Atmos, though it would be for my personal pleasure only.

Discussions like this are one reason I love QQ.
 

AYanguas

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Just because you have control of the bed sounds and the object sounds separately, within the Atmos mix session, shouldn't necessarily mean they are kept separate when they are rendered to the constraints of the Dolby TrueHD format. My understanding, with a typical Blu-ray release, all the sounds are within the 7.1 channels and the metadata moves them to the heights, and silences them in the bed through a complicated process.
Yes,

We learned that the Dolby Atmos container, at least in Dolby True HD, has a "core" 7.1 with ALL content. Thus playing in a 7.1/5.1 system we don't loose any sound.
Atmos and TrueHD 7.1 playback on 5.1 systems - Tests, Results, questions, experiences

The Atmos decoder, when heights/tops speakers are configured, then 'substract' the 'object' content from the floor channels, and 'add' it to the height channels, according to the speaker layout. If there are no height speakers, no operation is done and the full content 7.1/5.1 is played. It is not a 'downmix' but a 'core 7.1' played without the 'upmix' that would be the Atmos decoding process.
The way it sounds (without heights) may be good or not so good, depending on the mix. That's why some mixers prefer to do a separate 5.1 mix apart from the Dolby Atmos mix, taylored to their good taste monitoring.

I assume that this decoder behaviour would work equally well either the sounds are tied to 'bed' channels or configured as objects. (BTW, 'bed' channels are all speakers, except the LFE (SUB) , included the heights).

This is the theory, but we have to face now with several different formats and different decoders, in addition to the Blu-Ray Dolby True HD - hdmi - AVR:

1) Atmos in Dolby Digital+, as it is delivered in all streaming services, either Films or music.
2) Dolby MAT (I don't know much about it)
3) Apple spatial audio that has its own decoder for discrete speakers home cinema and for the binaural virtualized stereo.
4) Amazon Dolby Atmos just for the Echo Studio (??)
...

As @austinsignal is telling us, specially related to Apple, there may be (or they are) some decoders with different behaviours.

It would be a really BAD thing that some decoders does not include 'All' sound when they detect a non-Atmos system.

If some mixers/producers are afraid of that, and they avoid great height content and just put there a 'reverb copy' that if it is lost for someone it does not matter, then we have a Big Problem.
 

Quadmon

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I guess I need to hear a good Atmos system to give a proper opinion but around 1973 I set up something similar. I had an HK 100+ and four HPM 100 speakers. I bought a Lafayette quad amp and four 6” by 9” 3-way car speakers in the ceiling. It was great. Worked wonderfully. I would plop my ass down in my big beanbag chair and enjoy a roomful of sound. Very easy to find the sweet spot in a beanbag. Then we moved to another house where I couldn’t use that type of setup. I now have a large room (20’ by 28’) with large speakers. This also works well. The room is completely filled with sound. A friend stopped by yesterday and we listened to the Animals sacd and some others. He texted me this morning and said he had a great time and would I help him set up a surround system.
So with 50 years of listening to surround imo all that’s necessary is four channels. Put in a tape and listen. No adjusting levels, distances etc. And no sub to drive you crazy.
But a person has to adapt to what is current and we each have our own preferences.
 
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Yes,

We learned that the Dolby Atmos container, at least in Dolby True HD, has a "core" 7.1 with ALL content. Thus playing in a 7.1/5.1 system we don't loose any sound.
Atmos and TrueHD 7.1 playback on 5.1 systems - Tests, Results, questions, experiences

The Atmos decoder, when heights/tops speakers are configured, then 'substract' the 'object' content from the floor channels, and 'add' it to the height channels, according to the speaker layout. If there are no height speakers, no operation is done and the full content 7.1/5.1 is played. It is not a 'downmix' but a 'core 7.1' played without the 'upmix' that would be the Atmos decoding process.
The way it sounds (without heights) may be good or not so good, depending on the mix. That's why some mixers prefer to do a separate 5.1 mix apart from the Dolby Atmos mix, taylored to their good taste monitoring.

I assume that this decoder behaviour would work equally well either the sounds are tied to 'bed' channels or configured as objects. (BTW, 'bed' channels are all speakers, except the LFE (SUB) , included the heights).

This is the theory, but we have to face now with several different formats and different decoders, in addition to the Blu-Ray Dolby True HD - hdmi - AVR:

1) Atmos in Dolby Digital+, as it is delivered in all streaming services, either Films or music.
2) Dolby MAT (I don't know much about it)
3) Apple spatial audio that has its own decoder for discrete speakers home cinema and for the binaural virtualized stereo.
4) Amazon Dolby Atmos just for the Echo Studio (??)
...

As @austinsignal is telling us, specially related to Apple, there may be (or they are) some decoders with different behaviours.

It would be a really BAD thing that some decoders does not include 'All' sound when they detect a non-Atmos system.

If some mixers/producers are afraid of that, and they avoid great height content and just put there a 'reverb copy' that if it is lost for someone it does not matter, then we have a Big Problem.
this is great - thanks for all this. I spent last night thinking about this, and I think I know what happened. It was over a year ago when I was trying to get to the bottom of it, and my 64-year-old memory ain't what it used to be. So again, I could be wrong.

So - the Dolby ATMOS Renderer is the software used to create a Dolby Master, known as an ADM/BWF. The only way to QC mixes for Apple Music playback is to use the Renderer to create an MP4 - essentially a video file for playback via Quicktime. So, you send your mix to the client that has an Apple TV and a Dolby ATMOS AVR, and the playback should be representative of what the program material will sound like once published on Apple Music. I played MP4 mixes on my old home theater, which is 5.1 Denon DTS. As I recall, I lost the height material on these. This is prior to Apple creating a 5.1 for non-ATMOS playback - it's just an MP4 with ATMOS metadata in it, meant to be played with ATMOS AVR. Since I was just playing the MP4 on Apple TV with Quicktime, with no ATMOS decoding, there was just raw audio playing through my 5.1 system.

As an aside, this is just a bit of the larger issue we face when mixing for ATMOS, particularly Apple Music deployments. It is really difficult to guide the client through listening to something they can digest on whatever equipment they may have. ATMOS is a beautiful thing in concept (and reality!), but Apple makes it hard. The fact that they have their own binaural version (Spatial Audio) they create from a 5.1.4 downmix (!) is difficult to explain to clients. And getting the client through actually setting up their iphone/headphones to listen can be a long frustrating process. What version of IOS do you have? What version of Airpods do you have? Oh, you don't have Airpods, you'll need to go into settings and....and...then...Now can you hear the floor tom behind you? Are you sure?......etc etc. Despite all my complaining, Apple Music making a surround format to all, and all the marketing push, hardware development/integration (head tracking in Airpods!), integration between their DAW (Logic) and Dolby, work with auto manufacturers for deployment in cars, etc. There's no doubt in my mind that ATMOS will be ubiquitous at some point. And, every single person I've had into my studio to listen to mixes - I play the stereo mix for a period of time, then toggle in real time to 7.1.4 - have exactly the same reaction. Disbelief and a 'I want THIS' reaction.
 

~dave~~wave~

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...every single person I've had into my studio to listen to mixes - I play the stereo mix for a period of time, then toggle in real time to 7.1.4 - have exactly the same reaction. Disbelief and a 'I want THIS' reaction.

Thanks for joining the forum and transparently contributing your unique perspective.
These are interesting and challenging times for hobbyist and pro alike.

Looked at your studio gear list.
Wow! 🤠

ATMOS Monitoring

JBL 708p (L, C, R)
JBL 308MKII (8 - sides, rears, overheads)
JBL LSR310S sub
JBL Intonato24
JBL IntonatoDC
 
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