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7.1 Surround as poor-man’s Dolby Atmos 5.1.2?

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7.1 Surround as poor-man’s Dolby Atmos 5.1.2?

Postby Y-my-R » Fri Mar 18, 2022 8:20 pm

I have a 5.1 Home Theater system and understand how Bass Management/LFE/Dispersion etc. work, including various digital encoding formats, such as AC-3, Dolby Digital or DTS, and how they’re transmitted over S/PDIF type connections (used to do QA testing for these kinds of setups).

I never tried my hand at mixing or preparing audio for surround applications, though, and just never had more than a 2.1 speaker setup in the studio.

I’m thinking to change that. Originally, I thought I’d go with a basic 5.1 speaker setup… but since the D8B can do 7.1 surround, I was wondering if anybody ever tried to “misuse” channels 7-8 of the surround outs (i.e. as part of the 8 BUS outputs), to use them as the “height channels” that you need a minimum of 2 of, to comply with a Dolby Atmos 5.1.2 setup…?

I realize that I would have to record some rather odd surround panner automation moves, to have a signal that’s activated for channels 7-8 in the surround panner, stay at ear-height when panning, say, from front to back (I think I’d have to go from the front left corner, diagonal to the center/listening position (or probably rather "mid-way" so it doesn't pan towards the L/R center but stays all the way to the left), and from there, diagonal to the left rear corner, to have it behave like a “non-elevated” signal that just pans from front left to rear left.

Or for the reverse case, if I'd WANT a signal to appear further away above a listeners head, I'd just have to pan the signal further to the sides and towards where channels 7+8 are represented in the "7.1 style" surround panner, right?

For the most part, I'm thinking I'd circumvent that by turning channels 7-8 OFF for anything that should NOT appear on the height channel (I expect only a small percentage of channels to actually get routed to the height channels)… so, I’d only have to work around that the D8B doesn’t directly support “3D Panning” in the Atmos sound field, for channels that I DO want to have appear in the height channel. At least in my head, that sounds manageable.

Is anybody already doing that? If so, how does that work out for you?

Further, I understand that you can control the surround panner, by using the channel panner V-Pot and master fader panner V-Pot combined, to adjust the left/right and front/back positioning in “etch-a-sketch” style (the D8B manual calls it that).
I’d find this less than ideal, though.

Does anyone know, if the (software) surround panner in the D8B responds to external MIDI input, and if there’s a hardware MIDI controller (i.e. that has X and Y axis) that is suitable to remote control this? I’m thinking either a joystick type MIDI controller, like on a Korg Wavestation A/D, or a pad-controller like a Korg Chaos pad (or Apple Trackpad, if there’s a way to have it spit out MIDI), or maybe even a regular trackball, if the output could be converted to MIDI (that would be ideal, since I use a trackball, anyway… if that could just be switched to operate in surround panning mode and output MIDI, that would be PERFECT).
If the surround panner DOES respond to MIDI, is it the regular pan parameter, but on different MIDI channels for left/right and front/back? Or does it only respond to device-specific SysEX, like SO MANY things on the D8B?

Anyway… I haven’t ordered the speakers, yet, since I first want to understand what I’m getting myself into, and if my “7.1 as poor man’s 5.1.2 ATMOS” maybe has a severe logic flaw, that others on here could spot easily?

Curious to hear, who actually uses surround with their D8B. I was always curious, but never had the speakers, so there was no point in really clicking around with these features much. But I was VERY positively surprised when I realized that the D8B already has LFE and Dispersion settings for each channel, and about the pretty cool “Snapback” and “Morph” features I just read about, for surround panner animation. This beast still continues to surprise me!

Mostly looking to have fun with trying to mix some music in "basic ATMOS" and don't have high expectations. But sounds like a way to expand my mind and experience a little :)

Thanks in advance!
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Re: 7.1 Surround as poor-man’s Dolby Atmos 5.1.2?

Postby captainamerica » Fri Mar 18, 2022 10:57 pm

That train is coming so I think it's a matter of time before we all need to get onboard...right now, I don't see the need to invest time/energy into this new standard. https://www.sweetwater.com/insync/is-do ... -t1-insync
DAW: Genelec 8341,MacStudio, QuantumTB, Faderport16, DP, LogicProX, ProTools.BackupDAW:d8B, MacPro 2008 2xQuad-Core, MOTU (2408)LegacyDAW: A2000, Picasso II, Blizzard 68060@50 MHz|3xAD516 SunRize cards|HydraNexus Amiganet Ethernet.
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Re: 7.1 Surround as poor-man’s Dolby Atmos 5.1.2?

Postby Y-my-R » Sat Mar 19, 2022 12:10 am

Thanks for the link - just read it.

Sounds like they're using the term "LFE" as if it was exchangeable with "subwoofer channel" - but that's wrong, from my understanding. Funny how Sweetwater spends this much money to built the studio and show it off, just to commit such a blunder and tell everyone that they don't know what they're talking about, hahaha!

(The LFE is the low frequency signal from each of the satellite channels, that gets diverted to the subwoofer and ADDED to the actual dedicated subwoofer channel. They're not the same thing, Sweetwater!)

I read up about it a little more, and am/was aware that Dolby makes an ATMOS Renderer, and a panner plug-in, that requires the renderer. I understand that this is the "proper" way to do this, and wasn't really thinking that the D8B can "encode" a Dolby ATMOS 5.1.2 signal.

What I was HOPING I could do, was to monitor in 5.1.2, while misusing the side-channels from the D8B's 7.1 surround mode, and mount those 2 speakers on the ceiling.
I do realize that the pan movements involving the height channels will NEVER be accurate. But since I don't intend to match sound to movie effects, and have the "pew-pew" sound closely follow where the spaceship is on screen, but only want funny sound-effects and mix components that I can put in all kinds of places in the room, I'm thinking it might be "good enough" to mix enjoyable music in that format.

Considering that there's a renderer, and that I don't really have any experience in authoring surround content... I was hoping that I could simply record the 8 stems from my mix to somewhere else (e.g. via the 8 AUX outs on a DIO8 card back to the ADAT input on DAW audio interface), and then move the stems into a sort of "renderer" app, that lets me assign the 8 stems to the surround sound channels I want them on, and render it offline.

So, this:

1 - Front Left
2 - Front Right
3 - Center
4 - Back Left
5 - Back Right
6 - Subwoofer (incl. LFE)
7 - Height Left (i.e. BS ATMOS)
8 - Height Right (i.e. BS ATMOS)

...rendered into an AC-3 file, or whatever the preferred format for ATMOS encoded music is (what's the common format?)... or does it NOT allow you to render stems into a format that is considered ATMOS, and you HAVE to work with their funny 128 point routing matrix to end up with a compliant file?

I'm thinking to put up a surround speaker setup, anyway... but if I'm WAAAY off the mark with the ATMOS thing, and it's just not an option at all with the D8B, maybe I'd buy two speakers less and go with a basic 5.1 (I don't REALLY find a 7.1 system to be THAT much more interesting. The height channels, I DO find quite interesting, though).

Then again, I currently have the BUS outs on the patchbay. Might as well normal the speaker connectors onto the patchbay for these points, and patch my audio-interface's analog outputs to the speakers, if I wanted to mix in surround directly from the DAW... with a DAW that supports that, and the "official" Dolby ATMOS panner plug-in and renderer (probably on a separate computer, I know... and all that stuff costs serious money, I know, I know... still in the concept stage), it would at least be possible THAT way.

What got me exited about it was, to pull this off with the D8B, somehow, and just make my existing setup "do even more." I like "lemonade" ;)

I'm mostly a tech head and do music for fun. Exploring is always fun to me. That's why I'm thinking to enter this new (to me) territory. It doesn't have to meet compliance and I'm not looking to get Dolby ATMOS certified... I'd just want a system that makes use of 5.1.2 ATMOS "style" channel routing/immersion and gives results that kinda sound like it and are fun and enjoyable.
Ideally in a way where I could encode this, and play it back over "regular" Dolby ATMOS home theater systems or ATMOS enabled soundbars, etc. (Otherwise, if there's no output format that works, what's the point?)

And because I just accidentally typed this, but it could coin quite well what I'm trying to do:

Basically, I'd like a "Dolby ALMOST" system... a couple of twists in the spelling/sound-field are OK, if the music sounds as similar to "real" ATMOS, as "ALMOST" sounds to the name of this standard, hahaha ;)
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Re: 7.1 Surround as poor-man’s Dolby Atmos 5.1.2?

Postby Y-my-R » Tue Mar 22, 2022 12:42 am

For anyone following along:

I kept reading up on this, and IMO, it should generally be possible to do what I'd like to. So, something like this:

- Monitor in bullsh*t "Dolby ALMOST" via the D8B's 7.1 surround setting

- Use the 7+8 channels and D8B surround panner for "approximate" positioning of signals for the "height" channels (I wonder if I could figure out how to "re-map" all the MIDI values that are relevant for the height channels, in a way where fader movements don't have to be done in such a weird way, to "compensate" for side vs height positioning... but that's a project for later on, if I generally like "Dolby ALMOST" ;) ).

- I'm assuming at this point, that the D8B's "LFE" and "Disperse" features are simply routing portions of the signal to either all the satellites (i.e. disperse) or from the selected channel to the subwoofer channel (i.e. via the LFE channel), and that disperse by itself isn't creating a nice virtual "sound field" in a 7.1 stereo setup. If my assumptions are right, then disperse will also work as intended, if channels 7+8 are misused as "height channels."

- Of course I'm aware, that anything I'd be using in the D8B, that would impact the 7.1 sound field (e.g. artificial spaces like reverbs), would get unintentionally warped/distorted, if I were to have the signal come out of ceiling speakers instead of the sides. I intend to avoid using any such thing on the height channels... at least until done mixing/monitoring from the D8B. I could already plan to add in "3D/Surround" type effects after I'm done with D8B based mixing, and could add such effects to the surround stems "in post" - almost sort of like a surround pre-mastering step or something, haha ;)

- Logic Pro appears to already have the Dolby Atmos Renderer built in (I also downloaded the separate Dolby Renderer app and panner plug-in, but doing this via Logic seems simpler). This should allow me, to take my 8 stems from mixing via the D8B, place them into Logic, and assign the channels so that 7+8 end up being routed to the HEIGHT channels of the renderer app.
---> Since the 128 point placement and spatialization is applied during the step when rendering out via Logic's built-in Dolby-renderer, I expect that the appropriate Dolby ATMOS sound field will then be applied to my misused 7.1 "7+8" height channels, and that the virtual space will sound as intended by ATMOS (...and that it doesn't matter that these channels were originally the 7+8 side channels of a 7.1 setup).

I realize that the mix prior to sending everything through the renderer and after, is likely to sound rather different, and I'll have to try if this is workable for me (i.e. if it's only like "extra depth" at the end, or if it changes the room impression so much, that everything I did before on the D8B is meaningless and would have to be considered early on).

I think there's only one way to find out, though... I'll order the speakers soon, and will try. It'll likely be a few months until I'm ready to post results, though :)

And last but not least... I regret the strong language I used in my posts further above, and realize that I'm probably even WRONG about some of that stuff. I figured that some people must have seen this by now, anyway... so, I didn't try to hide it. But sorry for being such a hothead...
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