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Rear height placement to work with Auro 3D and Atmos

Dj7675

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Atmos isn't a mess. Dolby has been consistent about their overhead speaker placement since Atmos was released to the public. They have been as consistent about their speaker setup as Auro has been about theirs.

That overhead spec conforms with how an Atmos studio with a 7.1.4 monitoring system is to be set up. This ensures some sort of conformity between the production and reproduction of the content.
It is always nice to hear from something that does this for a living to get their perspective. In your setup(s) do you follow the Atmos Studio guidlines. Reading through them, they seem to have different/more specific guidlines. Hopefully this is related enough to this thread in regards to atmos placement…
 

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wseroyer

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This video is such bad advice, Dolby's system is very different in how it processes sound from AURO's. Set the Speakers up at the 45 degree angle 30 degrees apart from each other if you doing a Atmos system.
 

napfkuchen

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This video is such bad advice, Dolby's system is very different in how it processes sound from AURO's. Set the Speakers up at the 45 degree angle 30 degrees apart from each other if you doing a Atmos system.
For me his explanations were quite convincing. Also according to this comprehensive guide 45° angles will result in the sound losing "[...] its vertical coherence which means that the sound coming from the two speakers [meaning ground layer and height layer] are perceived as two different sources, even if there is a natural coherence in the source material". In my living room 30° is easily achievable, I also plan on using an AVR with Auro 3D upmixing ability to (hopefully) have the best of both - Atmos and Auro 3D - worlds. In the end it all comes down to compromises, at least for us poor peasants without dedicated home cinemas.
 

hemiutut

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This video is such bad advice, Dolby's system is very different in how it processes sound from AURO's. Set the Speakers up at the 45 degree angle 30 degrees apart from each other if you doing a Atmos system.
If that video is bad advice, you can tell him on his YouTube channel since here he surely won't be able to refute it.

Greetings
 

wseroyer

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If that video is bad advice, you can tell him on his YouTube channel since here he surely won't be able to refute it.

Greetings
I have, and I talk to Channa quite often on live streams and facebook. I've personally tried 30 - 45 - 55 degree set ups, and for atmos I believe that having them a 55 degrees works the best, it has the most convincing sound that stuff is above my head.

I personally am going by Steven Smiths guidelines and they line up best with what I'm hearing, to me 30 degrees just didn't sound good I got almost no height effect they just seemed to make the sound slightly taller, but it didn't have Helicopters above me or anything like that going 45 put objects above me, but they still seemed to be muddied by the front stage 55 degree's is where I got really good channel separation I could really discern things above me.

 

Reverend Slim

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For me his explanations were quite convincing. Also according to this comprehensive guide 45° angles will result in the sound losing "[...] its vertical coherence which means that the sound coming from the two speakers [meaning ground layer and height layer] are perceived as two different sources, even if there is a natural coherence in the source material". In my living room 30° is easily achievable, I also plan on using an AVR with Auro 3D upmixing ability to (hopefully) have the best of both - Atmos and Auro 3D - worlds. In the end it all comes down to compromises, at least for us poor peasants without dedicated home cinemas.
Except that vertical coherence is an Auro conceit that their underlying tech relies upon, not something Atmos is based around. The heights aren't in-line with the mains in Atmos, so you don't need to worry about the vertical stereo coherence that Auro uses to get good results. Think more vector-based amplitude panning than vertical stereo coherence. An argument can be made for lining up Atmos top front/rear in an arc so you're getting equivalent alignment of the heights and their corresponding adjacent ear-level speakers, which might work better in a home space... but isn't something taken into consideration in a theatrical space. We generally don't start losing sense of elevation steering between speakers until about 50-60 degrees, and we don't hear elevation on the vertical until amplitude is roughly equal between speakers, so a 30 degree placement per Auro can result in a much smaller effective range of precision for sounds between layers (15 degrees vs. about 23 for a stock 45 degree top front/rear placement).

But yeah, it's all about compromises. If you want to support Auro, they have a much narrower window for placement which won't be ideal for Atmos but will certainly work. If you disregard Auro, placement per Dolby's mix room standards (or planned using Dolby's Atmos room design tool) is ideal. Likewise, if you're better at hearing elevation than overhead, you may prefer the Auro-style layout anyway. If you're better at hearing overhead, a tighter spacing (like the aforementioned 55 degrees) of the heights may give you better results. The 45 degree top front/rear is meant to strike a reasonable balance between the two.
 
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