Questions & Answers

Improved Dolby Atmos defaults for rookies - avoiding the 7.1.2 trap with a 7.1.4 bed, or default object mode

+4 votes
2,043 views
asked Sep 28, 2023 in Mixing by junh1024 (260 points)
edited Sep 29, 2023 by junh1024

Hello & nice work on adding Atmos to S1. But there are big rookie traps. The default panner mode for mono & stereo is bed, and the maximum bed is 7.1.2. If no changes are made, then many users would just simply mix to only a 712 bed, defeating the purpose of DA, and reducing the spatiality - only half the area is available for home theater, and it's not  immediately obvious. A 712 bed would  impact most playback layouts since 712 has mono depth at height. About 50% of hollywood movies overuse the 712 bed, "Ready Player One" was basically 712 bed only. If the pros can't get this right, how would rookies fare? Here are 2 solutions: 

1. A 7.1.4 bed type & the default. This is available in Resolve, and Dolby Atmos composer as a "composite" (implemented as 7.1 bed + 4 objects internally). With a 714 bed, if you fail to change the track type to object, you won't lose spatiality at the top. This is a fallback measure for rookies.

2. Default pan type is object, rather than  bed for mono & stereo tracks is the master is DA. Users can mostly forget about loss of spatialility, and just focus on mixing & panning. Side effect: objects are limited. They are limited to 59 stereo objects, 118 mono objects, or a combination of both (moving mono objects sound better in surround btw) at which point you need to start sending tracks to bed, or grouping tracks and have them output to object bus. But it's a small price to pay for having access to the whole area, instead of half for using the 712 bed.

3. In line with the rookie theme, most DA  projects in S1 would be music. Dolby's music delivery spec says the 51 downmix type should be "direct render", but the default is currently loro. It should be changed to "direct render" to help rookies. "direct render" is beneficial in that it's the only 51 render mode that doesn't warp the soundfield to the back.

Developers have huge power by choosing the defaults which many people won't change. Please use this power for good and implement (some of) these to improve the result of DA mixes.

Thank you.

4 Answers

+1 vote
answered Sep 28, 2023 by stuartmaxwell (4,180 points)

@jili3 

Found this interesting, although I'm not totally sure what to learn from this in terms of how best to use S1 as is. Are you saying that it is better to switch channel pans to use 'Spatial Object Panner' rather than 'Surround Panner' then we are all good ?

0 votes
answered Sep 29, 2023 by junh1024 (260 points)
@stuartmaxwell;

reply1: 2: short answer, yes. I have added more info to options 2&3. I also replied to your other question on AS.

BTW, my background is surround music as a hobby. What's your background?
0 votes
answered Sep 29, 2023 by stuartmaxwell (4,180 points)

@jili3 

Thanks, this is a lot clearer, also been digesting a lot more on the topic and beginning to get some headway :)

Ohh my background, hmm semi pro musician/producer I guess, always curious and learning, getting my feet wet with atmos .. was messing with atmos when logic included it a while ago but didn't enjoy being back in logic (it was my #1 DAW from about 10 years ago, I'm an S1 convert since ) . So I was pleased to see S1 adopt atmos.

0 votes
answered Feb 26 by christianmiekus (950 points)
edited Mar 26 by christianmiekus

Pretty important topic, but it's worth mentioning, that the bed limit is 7.1.2 ... a 7.1.4 bed doesn't exist and never will for compatibility reasons regarding Dolby:

https://professionalsupport.dolby.com/s/article/Why-doesn-t-the-Renderer-have-7-1-4-or-larger-beds?language=en_US

The recommendation is using a 7.1 bed combined with 4 static objects for the ceiling.

BUT that is impossible in Studio One, as far as I can see, especially, when I want to use FX channels for 7.1.4 reverb (e.g. with Open AIR), where the 7.1.4 speaker layout will be downsized to the bed size!

I think we will need an additional object bed? Or did I miss something?

PS: Ok, I could create 4 Mono FX Channel Objects for the ceiling, but how to route them, if I want 7.1.4 reverb in combination with the recommended 7.1 bed?

PPS: The trick is routing every bed track to a 7.1.4 FX Channel, which then will be routed to the 7.1 bed. To get the ceiling we use sends to two further 7.1.4 FX Channels, one for the ceiling front (two channels) and one for the ceiling back, which both use the Mixtool as an insert to filter only the needed channels. Then we route these two "helper channels" to two Stereo Ceiling Objects, one for the front and one for the back pair.

Bingo, now we have a 7.1 bed with four ceiling channels (object based), which drastically simplifies mastering.

If now Studio One wouldn't have a bug, that distorts objects, when using sends to FX Channels or side chains, we could use a similar setup for object's reverb, delay, etc.. Presonus is informed and working on a fix ... I hope it won't take ages.

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