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HiRez Poll Lennon, John - GIMME SOME TRUTH (The Ultimate Remixes) [Blu-Ray Audio]

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Rate the BDA of John Lennon - GIMME SOME TRUTH (The Ultimate Remixes)


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kokishin

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If the 7.1 is a 'core' component in a Dolby Atmos file, is not the 5.1 also a core, for legacy purposes? That is, for hardware with pre-Atmos Dolby decoders?

We can extract and analyse cores without Atmos enabled using tools like MakeMKV. Would it be right to say that the only way to objectively analyse Dolby Atmos output in 7.1 (or 5.1?) with Atmos enabled (i.e., with extra channels mixed in to it) would be to record the analog output? Or is there any software yet that does Atmos decoding and can output in multiple channel formats? Because it looks like the comparisons people are interested in include

x.1 core vs x.1 Atmos-enabled
DD vs DTS

Could the DTS cores look so similar yet distinct from DD due to having had Atmos channels mixed in to the DD core before DTS encoding? IOW, the DD 5,1 core + Atmos channels folded in = DTS 5.1 ? This might make sense because you could not get the *Atmos-enabled* DD 5.1/7.1 experience from DTS without doing that .

It would require Atmos-savvy software tools to demonstrate, though.
DD is not a core component of DTHD. DD is a separate track and is a BD requirement.

DD does not support Atmos.

DD+ and DTHD support Atmos.
 
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ssully

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If I understand correctly, then, a Dolby TrueHD stream (which can be up to 16 channels and is the bitstream by which Atmos is implemented) if played on a TrueHD capable and enabled system, can downmix from higher to lower channel output, including 5+.1+ >> 5.1. However if a 5.1 system lacks an enabled TrueHD decoder, it will play the separate, dedicated DD 5.1 bitstream.

But a TrueHD Atmos 7.1 file , played on a system with a TrueHD decoder but not Atmos configuration, plays the 7.1 'core' (in the case of Lennon here) of the Atmos bitstream with Atmos elements folded in. Is there any system configuration (e.g., Dolby PLIIz but not TrueHD) that would play the TrueHD 7.1 core without Atmos channel fold-in?
 
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Strilo

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Isn't there an entire thread elsewhere for this discussion of the possible issues with the different formats of the surround mix(es)?

EDIT: There is.

 

ssully

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Isn't there an entire thread elsewhere for this discussion of the possible issues with the different formats of the surround mix(es)?

EDIT: There is.


Unfortunately, that only only pertains to the two 5.1 mixes. I agree that it would be great to combine all research into what is going on in the various permutations of format and channel number, into one thread. I've copied these two posts of mine over there now in any case.
 
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jimfisheye

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I always thought it worked the other way around. The 7.1 already has the object info imbedded in it. Running it through an Atmos decoder takes that info and routes it to the additional height channels and suppresses it (to whatever degree the mixer specifies) in the 7.1 bed. Kind of like a digital version of a matrix encode. Is this incorrect?
According to the tech documents, that is incorrect.

For that to be true, you would need a proprietary format that was not 7.1 PCM surround. A 7.1 file is a 7.1 file is a 7.1 file. It's an established format with 8 channels of PCM audio in a single file container.

What's going on is there ISN'T a dedicated new proprietary single file format used for atmos. The designers went with delivering the content in two parts: the 7.1 bed as a 7.1 file and the height+objects as metadata. (Both muxed into a single container format like mkv or bluray but separate components.) The 7.1 element is to go straight to the 7.1 channels. The metadata is to be directed to the height and object channels. The metadata has the ability to be scaled to speaker arrays that don't have the complete compliment of channels vs the full system. (Including folding it into the 7.1 channels in a system with no height or object channels.) Ambisonic techniques are used to scale the height and object channels to smaller arrays.
 

himey

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From this discussion it seems the Atmos 3D objects are simply discarded, unless you have a newer version of a Dolby TruHD decoder which my guess would be in the newer Atmos processors (?).

So if your receiver does Atmos you should be able to downmix to 7.1 or 5.1 and still get the Atmos 3D objects inserted into the downmix?

Edit...after reading that again, the objects are in the 7.1, and routed to the additional height channels and deleted from the bed once processed. So I guess the objects aren't discarded?
 
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LuvMyQuad

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From this discussion it seems the Atmos 3D objects are simply discarded, unless you have a newer version of a Dolby TruHD decoder which my guess would be in the newer Atmos processors (?).

So if your receiver does Atmos you should be able to downmix to 7.1 or 5.1 and still get the Atmos 3D objects inserted into the downmix?

Edit...after reading that again, the objects are in the 7.1, and routed to the additional height channels and deleted from the bed once processed. So I guess the objects aren't discarded?
I stated that was how i thought it worked in thread #159, but was told that was incorrect.
 

himey

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I always thought it worked the other way around. The 7.1 already has the object info imbedded in it. Running it through an Atmos decoder takes that info and routes it to the additional height channels and suppresses it (to whatever degree the mixer specifies) in the 7.1 bed. Kind of like a digital version of a matrix encode. Is this incorrect?
I had someone else tell me this disputes that idea and "Therefore the Atmos data (objects) is added as an extension to the format and put into the bitstream, they do not live in the 7.1 bed." I told him he was reading into to that his opinion and that link wasn't being specific.
 

himey

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I had a conversation with a guy who mixes TV shows to Atmos and the way he put it, it is up to the mixing engineer to make sure the downmix sounds good during the production. During the actual mixing, care is needed to ensure it will sound good with both old 2D setups and of course with height speakers. This is an excerpt : "I do find that I mix in Atmos with an awareness of how the downmix will be created (and this is just from experience). For example I don't put a lot of signal up high and in the back because it sounds almost indistinguishable from signal panned to the surrounds. Likewise I don't use a 7.1.2 bed as signal sent to the .2 tends to cover the entirety of the height space in Atmos and then fold down to be heavier than I would like in the side channels. When I use height for objects that are fixed I usually stay in the front half of the room and I almost never use 100% height. This way any objects that I'm placing in space will always have a focal anchor to the front array weather that be L+R or LCR. When panning objects I don't worry as much about it because movement tricks the brain quite a lot and almost any objects that "fly" overhead will translate very well when being panned rear-side-front or vice versa."

So rather than getting too lost in the technical details, for now, I am just going to trust that the mixer is going to make the effort to get it right on both fronts. The multiple substream's is confusing to me now and I need to gather more information about it to fully understand, but for now my impression is the first substream does indeed carry the entire soundtrack, so nothing is actually discarded, even if playing back on a simple 2 channel system.
 

jimfisheye

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That's accurate. There is absolutely an intentional compromise in most broadcast surround mixes to make them so they fold down to stereo. The stereo mix is the target and what's left of the surround mix is what's left of the surround mix. These sound like the front heavy more ambient surround mixes that everyone around here hates. They're intentionally only making one mix and making it one size fits all. And that does kind of sound like the cookie cutter approach this album was subjected to.
 

himey

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That's accurate. There is absolutely an intentional compromise in most broadcast surround mixes to make them so they fold down to stereo. The stereo mix is the target and what's left of the surround mix is what's left of the surround mix. These sound like the front heavy more ambient surround mixes that everyone around here hates. They're intentionally only making one mix and making it one size fits all. And that does kind of sound like the cookie cutter approach this album was subjected to.
On a similar note, he mentioned that a lot of new Atmos mixes for TV are just automated from the original two channel mix, sadly, but I am not going to get into that here...
 

harync

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I had a conversation with a guy who mixes TV shows to Atmos and the way he put it, it is up to the mixing engineer to make sure the downmix sounds good during the production. During the actual mixing, care is needed to ensure it will sound good with both old 2D setups and of course with height speakers. This is an excerpt : "I do find that I mix in Atmos with an awareness of how the downmix will be created (and this is just from experience). For example I don't put a lot of signal up high and in the back because it sounds almost indistinguishable from signal panned to the surrounds. Likewise I don't use a 7.1.2 bed as signal sent to the .2 tends to cover the entirety of the height space in Atmos and then fold down to be heavier than I would like in the side channels. When I use height for objects that are fixed I usually stay in the front half of the room and I almost never use 100% height. This way any objects that I'm placing in space will always have a focal anchor to the front array weather that be L+R or LCR.
Thanks for sharing his explanation. It explains the what I noticed with "Sweetness Follows" from the Atmos version of REM's Automatic for the people. In Atmos the cello is localized in the heights (primarily left front ceiling on my 5.2.4 system), but on a non-atmos system it ends up in LF, C, RF, an LS.

When panning objects I don't worry as much about it because movement tricks the brain quite a lot and almost any objects that "fly" overhead will translate very well when being panned rear-side-front or vice versa."
I think this explains why we are seeing such a learning curve with Atmos music mixes. In most movies and TV shows, everything other than dialogue and background noise is fleeting and may only be audible for a few seconds and our brains are much more forgiving.
 

jimfisheye

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Hmmm...

If I was given a mastering job and requested to make it volume war crude by the client, I might wonder if I could get away with "accidentally" muxing the wrong file to the dd stream version? (ie the raw mix)
Maybe instead of busting this guy for the loud mastering we should be praising the heroics of liberating the mix!

Not to get anyone in trouble. Of course it was a completely innocent accident!
 

James Jay

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to simplify: if you are playing the decoded Atmos mix (Not the 7.1 Atmos core) with a complete 7.2.4 speaker setup - are the side surround speakers / rear surround speakers/ or Atmos ceil speakers - reduced in volume -6db from the front speakers? I’m getting confused here. Can anyone break this down for me. Thanks
 

tezzalavell

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well just a quick review. We do not need to talk about the Music ! I have read all the Dolby , Atmos , DTS reviews and I concur the DTS MA rears were low. So Low I ripped it ! . What did I find , fronts and centres Hard limited . I cannot understand why an audiophile disc has to be hard limited . If you have dynamic range and a volume knob your sorted. So after ripping I Lowered the fronts and centre put them through Audition and gave them pseudo DR by phase shifting and upped the rears. Yes a lot of the early stuff is basically double stereo with ambience but at least now I have immersive ambience and immersive active rears on the other tracks . Surround in my opinion means equally balanced volume . I do not want to be craning my neck to hear subtleties. To finish The Beatles Datum is still the LOVE surround album which is clean, dynamic , active , immersive . Brilliant !
I gave lennon 8 cause of the Music .
 
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