5.1.4 to 7.1.4 Upmix?

Since this is where 99% of the ATMOS questions are placed, I figured it was okay to ask this one here.

My setup is still 5.1.4. What happens to a 5.1.4 ATMOS print when played through a 7.1.4 player?

Is it automatically upmixed by the decoder to spread the image into the sides? All the conversations about 9.1.6/9.1.4/7.1.4 are always about downmixing to binaurel or immersive stereo. But I’m not seeing much in the opposite direction. Will the immersive (but essentially stereo prints) expand out into the full range 9.1.6/7.1.4 spread?

This is a long but well-worth-it read:

Some quotes:

" Dolby Atmos reproduces this immersive soundstage independent of a listener’s speaker configuration, meaning the creator and consumer don’t have to have the same speaker setup."


" How Dolby Atmos Works

Dolby Atmos lets mixers manipulate any audio track as an object that can be placed anywhere within a 3D space, without directly assigning it to a particular speaker. Dolby Atmos brings a height element to the soundstage: Typical Dolby Atmos speaker configurations include seven speakers, a sub, and four height speakers (7.1.4), but Dolby Atmos is capable of processing up to 128 channels of sound; can be routed to up to 64 speakers; and by applying virtualization, can deliver immersive experiences on a sound bar, pair of speakers or Headphones. Because Dolby Atmos receivers compensate for various speaker setups, producers don’t have to adapt mixes for every configuration."

Read that last sentence, it answers your question. You do not need to worry about what speakers YOU have. Dolby automatically plays back the program material in however many or few speakers the playback device or setup has, AUTOMATICALLY. We do not have to worry about numbers of speakers anymore. This is what attracted me to coming back to Nuendo btw.


What noeqplease said.


Well, isn’t the more ‘specific’ question what happens specifically to a 5.1 bed after it’s been upmixed to 7.1 (if it is)? While objects have xyz coordinates which allow very fluid ‘scaling’ the beds are just like regular mixes, no? So a 5.1 can’t be ‘unmixed’ and therefore the question is interesting I think.

Let’s say you have a 5.1.4 group that you’ve placed content into and it is set as a bed in Atmos (so it receives 10 channels) - what happens to that bed in a playback environment that is 7.1.4?..

(I’m guessing Dolby probably has docs on it somewhere)


What I learned from my testing is that when you lay a 5.1 bed into an Atmos mix rendered as 7.1.4, the F, C, R and LFE channels lock exactly to their counterparts. The 5.1 surround channels go to both side and rear in equal amounts. There is no sonic separation between the side plane and rear plane.


Does that make a SONIC difference, like the difference between “Phantom Center” and “Real Center (Mono)?”

The reason I’m asking is because I’m looking for “Gotcha’s!” I keep monitoring the consumer side of this equation and I keep reading/hearing/watching (videos) about translation issues regardless of proper production of content.

Example: A plane flies over head in a ATMOS streamed movie (BTW, what are they calling ATMOS physical content? Immersive DVD? ATMOS-Ray v Blu-Ray?). The consumer has a 5.1.2 playback system. So when the plane flies over head on the FRONT “.2 speakers,” it sounds like it crashed when it hits the REAR Surround speakers. was there a way to avoid that on the construction side? Maybe put more plane flying sound in the Bed to lesson that jarring effect. Is it even possible to avoid these kind of translation problems? Should I be using the stereo immersive version as the base line (if it sounds good there, it’ll absolutely sound fantastic on 9.1.6 playback) before I consider it a proper deliverable?

I’m not quite sure what you’re asking. Atmos would render the left surround channel from a 5.1 mix as a phantom center between the left side and left rear (it might not be a 50/50 mix but that’s the idea). I wouldn’t really call that a “sonic difference” though, because the tonality isn’t chaning, any more than panning a signal from left to right in front.

If I wanted a plane to fly overhead in Atmos, I would just pan it from front height to rear height, and fade it (lower gain) and maybe add diffusion as it flew away like it would in real life. On a x.x.2 system, depending on the devices settings, the plane would sound like it was between the ceiling and the rear as it faded away. It wouldn’t sound like it crashed. You just have to let each playback system interpret your intent as best it can. I don’t think you can “game” it to sound good for one speaker configuration without making it weird for everyone else.

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Well that’s what you’d hope for. But according to the Consumer AV Tech videos I’ve seen on YouTube, The “Pundits” claimed that the effect was pretty jarring to have it suddenly drop from the height speakers to the surround rear speakers. I don’t really know and you’re probably right about not being able to “Game the system.”

I do find a difference between a full mono center signal and a phantom one. I don’t have a problem with either and the phantom option makes perfect sense (what other way could it work). I guess my concern is about multiple phantoms IE; 5.1.4 going to 9.1.6. Now is it going to sound like Phil Spector’s "Wall of Sound?’

Speaking of “Wall of Sound,” I’m looking at all of these charts on speaker placement for the best results and I’m noticing that in all of the pictures of the commercial studios, NONE OF THEM USE THOSE PLACEMENTS. Rather, they all seem to be using the Movie Theater Placement arrangement, in which case even the Bed is a height speaker series. So, I’m guessing that this is all relative? In fact, the more I think about the 7.1.4 array, the more 5.1.4 makes sense when considering a consumer home placement arrangement. Unless the homeowner builds a purpose built home theater, those side speakers are going to be a major problem for incorporating them into a “living Room/Family Room” Design and I can already hear a LOT of push back from wives all over the world! :laughing:

Anyway, thanks for the information. Much appreciated! :wink:

This is the crux in the whole thing.

Dolby Atmos material (in DD+ or DolbyTrueHD) delivered to the consumer does not know of any 5.1.2, 7.1.4 or 9.1.6 speaker layout. The Dolby Decoder will map the “intent” to the speaker setup available.

If playing (rendering) the material on the consumer’s equipment, it is the Dolby Atmos Decoder’s job, to map the material the best as it can to what the user is having available. This can be any from 1.0 to 9.1.6 speaker setup and even more.

If using 5.1.2, it tries to best render height sounds to the (2) height speakers. May be semi-optimal. It would be better replay quality if the decoder can utilize x.x.4 (e.g. 7.1.4) or even 9.1.6 speaker setups.

LG, Juergi

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