How are Dolby Atmos mixes created?

[Chrispy]

Seems most apple atmos "conversions" are simple algorithms rather than any particular human content aside from that....

 

[kemmler3D]

generated by playing the stereo track in a physical space and recording room ambience.

Hmm, really... is this really better than using a high quality 3D reverb plugin?

 

[holdingpants01]

Hmm, really... is this really better than using a high quality 3D reverb plugin?

different from algorithmic plugin for sure, but if one is set on recording the room with sound coming from the speakers, it's much easier to just use properly made ambisonic convolution impulse reverb like Altiverb

 

[holdingpants01]

Here's interesting interview about Tom Petty's music atmos transfers, especially the multitrack part

 

[goat76]

Apple Music apparently does not accept Atmos tracks upmixed from stereo; they must be from the multitracks, or generated by playing the stereo track in a physical space and recording room ambience. So, I’m very interested too in how older recordings are rendered in Atmos…following this thread and the one on QuadraphonicQuad.

Do you have any examples of Atmos tracks that have been generated by playing the stereo track in a physical space and recording the room ambiance?

 

[Dogen]

Do you have any examples of Atmos tracks that have been generated by playing the stereo track in a physical space and recording the room ambiance?

This is the best article I could find, for Kind of Blue.

Dolby Atmos Music: It’s Different When You Mix Music-Only - Mixonline

I have worked in surround formats specifically for music before. I can say that mixing for Dolby Atmos Music takes that freedom to the next level.

www.mixonline.com

 

[DVDdoug]

or generated by playing the stereo track in a physical space and recording room ambience.

That would be stupid! (That doesn't mean they aren't doing it.) That's how they used to make "artificial" echo/reverb before plate reverbs or digital was invented. Capitol Record in LA has a big underground echo chamber and I believe it's still in use.

 

[Dogen]

Here’s a link to Apple’s audio requirements:

https://help.apple.com/itc/videoaudioassetguide/#/itcf946aaace

Excerpt:

Immersive audio source must meet the following requirements.

Dolby Atmos music deliverables​

• Dolby Atmos audio files generated from stereo mixes are not allowed. Specifically:
  • A Dolby Atmos track must be created from multitracks or stems created from multitracks.
  • Upmixing from a stereo release is not allowed.
  • Extracting stems (“de-mixing”) from a stereo release is not allowed.
  • A Dolby Atmos track consisting only of a stereo mix placed in the sound field with added ambience or reverb is not allowed.

 

[mhardy6647]

Apple Music apparently does not accept Atmos tracks upmixed from stereo; they must be from the multitracks, or generated by playing the stereo track in a physical space and recording room ambience. So, I’m very interested too in how older recordings are rendered in Atmos…following this thread and the one on QuadraphonicQuad.

How do they know?

 

[goat76]

This is the best article I could find, for Kind of Blue.

Dolby Atmos Music: It’s Different When You Mix Music-Only - Mixonline

I have worked in surround formats specifically for music before. I can say that mixing for Dolby Atmos Music takes that freedom to the next level.

www.mixonline.com

Thank you.

Yes, I know that re-amping the new mix done for Atmos is sometimes done if the original stereo recording didn't contain a separate recording of the original ambient of the recorded space. What I meant was if you know of any Atmos releases that are just the original stereo releases with some added ambient applied to them (as in the last point in Apple's rules of what isn't allowed).

In the case of the Atmos version of Kind of Blue, they made a new mix out of at least the 3 originally recorded tracks and panned them to the 3 front channels (L-C-R), which they then re-amped in the studio for adding ambient to the rest of the channels. So even if they only had 3 tracks to play with, it's still not the same as if they had just used the original 2-channel release and just added ambient to that.

 

[dshreter]

I’ve seen Brad Wood talk about his process and listened to some of the tracks in an Atmos room. This video has a nice overview from him, and later in the video you can see some specific detail on the tools and methods that are used.

 

[DWG]

I appreciate all the discourse, so far. Please keep it up! I find the videos most enlightening and found some similar titles on youtube. As we speak, I am converting my home theater from 5.1 to atmos (5.1.4). Probably move to 7.2.4 if I end up liking what I hear. The challenge for me (besides cost!) is placing four height speakers on the ceiling in our already finished space. I have 15-20 atmos titles on blu-ray. It will be interesting to see how those compare to their Apple music counterparts.

 

[krabapple]

I only speak in general when I say "big and famous". There are of course many original analog multitrack tapes that are kept from recordings of both famous and smaller bands, and they can all be used to create Atmos mixes.



I have Tidal which provides Atmos music, so I have listened to a fair deal they have in their catalog, and everything of what I've heard seems to be Atmos mixes made from the original multi-track recordings.

How quickly it can be done is dependent on every single recording, what type of music it is, and how the recordings were done. Some music like rock, jazz, and classical will probably not go that far from how the stereo mix is done, but it can still be highly complex even if it still sounds like all of the instruments are located in front of the listener. Professional mixing engineers are usually very fast knowing what type of mix will suit a particular type of music, they know when to keep it "traditional" and when they have free hands to make a more effect-like mix (that may take more time to do).

Which brings us around to my original question: is or is not the plethora of new surround mixes being generated -- after years of relatively sporadic production for physical discs since around the year 2000 -- extraordinary?

You acknowledge that , even if it may be 'relatively simple' it still takes time to generate a new surround mix -- and I'd argue, more time than to generate a stereo mix. But hey, even if it was just stereo remixes : how, logistically, is this being done??

I am hoping someone with a foot in the industry could chime in with more than speculation.

 

[krabapple]

Seems most apple atmos "conversions" are simple algorithms rather than any particular human content aside from that....

Does it seem that way? According to whom?

This is the best article I could find, for Kind of Blue.

Dolby Atmos Music: It’s Different When You Mix Music-Only - Mixonline

I have worked in surround formats specifically for music before. I can say that mixing for Dolby Atmos Music takes that freedom to the next level.

www.mixonline.com

Please stop focusing on this, folks. These are niche cases. This was already done back in ~2001 or so for the '5.1' releases of Kind of Blue and In a Silent Way, whose sources are 3-track tape. The mixers literally recorded the room sound during playback of the 3-track, and made that the surround left and right content for the multichannel SACD release. (IIRC these were 5.0 -- no/empty LFE)

Most recordings since the 1960s are multitrack -- more than 3 track.


I'm sure it's done when there are no multitracks available, but most Atmos streams I've listened to do not sound like stereo + 'room ambience'.

 

[krabapple]

None of this is answering the question, how are SO MANY Atmos mixes -- with actual content in surround channels, not newly recorded room ambience -- being generated so fast?

 

[goat76]

Which brings us around to my original question: is or is not the plethora of new surround mixes being generated -- after years of relatively sporadic production for physical discs since around the year 2000 -- extraordinary?

No, I don't think it is that extraordinary when you consider how different Atmos as a format works in comparison with previous attempts at creating surround formats for music. With the earlier surround formats which were all "hard-set" channel-based audio formats, the consumers were expected to install a minimum of 5 loudspeakers in their living room which was of course doomed to fail right from the start as most homes have a hard time accepting even 2 loudspeakers in this time of age.

Atmos on the other hand is an object-based audio format where the same audio file can be listened to in a pair of headphones and up to what, 34 speaker systems. Every single consumer already has a pair of headphones which is the main focus and the minimum requirement, and the way most people are already listening to music. So with this format, the hardware is already in place in comparison to the previous surround formats for music.

So with the hardware already in place and with a large corporation such as Apple punching for the format to be a success, I don't think there is anything extraordinary about so many in the industry jumping on the bandwagon and creating a lot of content for the format in a relatively short amount of time.

You acknowledge that , even if it may be 'relatively simple' it still takes time to generate a new surround mix -- and I'd argue, more time than to generate a stereo mix. But hey, even if it was just stereo remixes : how, logistically, is this being done??

As @holdingpants01 and I mentioned earlier, there's not necessarily that much extra job left to do to create a surround mix if all the work for a stereo mix is already done. Much of the processing of sculpturing the individual sound objects in the mix is already in place, so the mixing engineer can put most of their focus on moving these sound objects around in the three-dimensional space, and depending on the nature of the music, some of the mixes of music genres will work best in a rather conservative way that doesn't goes too far from how the original stereo mix was panned, while other types of music can be mixed more creatively. Professional mixing engineers will get the hang of the possibilities, and with most of the "detail work" already done for the stereo mix, they can probably finish most Atmos mixes in a relatively short time.

I am hoping someone with a foot in the industry could chime in with more than speculation.

Yes, that could have been interesting.

 

[Godataloss]

Gotta say that 95% of Atmos movie soundtracks are no more immersive than quality 5.1 mixes of ten years ago.

 

[goat76]

This is not an Atmos track, but I made a 5.1 surround mix today out of an old song by the Beatles just to show you that it doesn't have to take that long time to remix a song to a multichannel track. The actual mixing didn't take me longer than a few hours, what took me the longest time was to figure out how to get the routing right in my DAW for 5.1 channels. I'm sure the professional mixing engineers could have done it in no time.

The track can be played using Media Player on a Windows computer set up for surround sound connected to an AV receiver, but it probably works with other players too that are capable of playing surround sounds.
The file is just 30 seconds long (fair use) and must be downloaded to be able to play it in surround mode, playing it directly from Dropbox will automatically downmix it to stereo. I think the mix sounds pretty cool in comparison to the original "ping-pong" stereo version... or?

Dropbox

www.dropbox.com

 

[krabapple]

You aren't a pro mixer. You aren't mixing in Atmos. And I'm not convinced you have a clue how many Atmos mixes are being dumped into streaming every week. Hence your posts are full of suppositions.

Here's an actual Atmos mixer. Does his mix process (after all the setup, which he can use in multiple mixes) sound like it happens 'in no time'?

 

[goat76]

You aren't a pro mixer. You aren't mixing in Atmos. And I'm not convinced you have a clue how many Atmos mixes are being dumped into streaming every week. Hence your posts are full of suppositions.

Here's an actual Atmos mixer. Does his mix process (after all the setup, which he can use in multiple mixes) sound like it happens 'in no time'?

I watched the video and also part 2 and there are no significant differences between mixing in 5.1 surround and Atmos other than the track count and the ability to move the sound objects in the vertical plane in Atmos.

The first video you linked was all about setting up the system, and as you mentioned yourself, that template is saved and can then be used for all the other upcoming Atmos projects so once that is done it may just need a few tweaks. I had to set up routings in a similar way as he did to be able to mix in 5.1, and that was the most time-consuming thing of the whole process.

The second part was about mixing, but there weren't any spectacular things done that were much different from what people are doing for 2-channel mixing. It's the same tools and the only difference is that Atmos allows the mixing engineer to play around more within a larger space like in a 5.1 mix, but now with the vertical plane added to the palette. The project he worked on in the video was the type I would call a "creative" type of mix, he probably wanted to show some spectacular movement that can be easily implemented with different plugins, and as I mentioned earlier, a mix like that can be a little more time-consuming. But most Atmos mixes I've heard are rather static as most genres work best with a more realistic soundstage without moving sound objects, and those aren't that complicated to make if a stereo mix has already been done. Professional mixing engineers work fast, they know their tools, and they often get an idea of what will suit a certain mix rather quickly.

Are you suggesting most Atmos tracks and albums are AI-generated mixes?