Impact of lossy compression when streaming Atmos

Help Support QuadraphonicQuad:

LuvMyQuad

2K Club - QQ Super Nova
Joined
Aug 12, 2010
Messages
4,080
Location
Western NY
Lots of us don't have more than 5.1, but the Atmos mixes can still be enjoyed. Tons of new surround content for those of us with 5.1 systems.
I find that Atmos tracks mix down to 5.1 quite nicely. Nothing seems to get lost. Nothing seems to get overemphasized. Maybe a bit different placement.
 

marcb

600 Club - QQ All-Star
Joined
Nov 15, 2010
Messages
637
I find that Atmos tracks mix down to 5.1 quite nicely. Nothing seems to get lost. Nothing seems to get overemphasized. Maybe a bit different placement.
Am I the only one who finds - on Apple Music - the rears for Atmos mixes folded down to 5.1 to be about 3dB quieter than the rears for the true 5.1 and quad mixes?
 

LuvMyQuad

2K Club - QQ Super Nova
Joined
Aug 12, 2010
Messages
4,080
Location
Western NY
Am I the only one who finds - on Apple Music - the rears for Atmos mixes folded down to 5.1 to be about 3dB quieter than the rears for the true 5.1 and quad mixes?
My comment was directed exclusively toward fold downs from disc and/or files. I actually can't fold Apple music Atmos streams down to 5.1, as the AVP I use wont allow it. If it comes in as Atmos, and the equipment is Atmos capable, it has to be processed as Atmos (I'm told its a Dolby requirement???) . The only other valid option on my AVP is a fold down to stereo. For whatever reason, that is allowed.

I could probably do it by changing the AVP setup to indicate there are no height channels. But I haven't done that (why would I ?)
 

marcb

600 Club - QQ All-Star
Joined
Nov 15, 2010
Messages
637
My comment was directed exclusively toward fold downs from disc and/or files. I actually can't fold Apple music Atmos streams down to 5.1, as the AVP I use wont allow it. If it comes in as Atmos, and the equipment is Atmos capable, it has to be processed as Atmos (I'm told its a Dolby requirement???) . The only other valid option on my AVP is a fold down to stereo. For whatever reason, that is allowed.

I could probably do it by changing the AVP setup to indicate there are no height channels. But I haven't done that (why would I ?)
Sorry I was just piggybacking on your post to ask a question.

FWIW, my AVR is atmos capable too. If you really care enough to experiment, turn your atmos speakers off. Your AVR should then fold Atmos down to 5.1.

Could my ATV4K (or my AVR) be throwing out information rather than folding into the rears? I don’t think so, but maybe I’m wrong.
 

Ephi82

Well-known Member
Joined
Jan 2, 2016
Messages
171
Location
S FL
Maybe I misunderstand, but if your AVR is set up for no height/ATMOS speakers, ATMOS height content is part of what is sent to the surrounds?

If the AVR is set up for an ATMOS configuration,with height speakers, it uses the ATMOS data and sends it to the heights…
 

LuvMyQuad

2K Club - QQ Super Nova
Joined
Aug 12, 2010
Messages
4,080
Location
Western NY
Maybe I misunderstand, but if your AVR is set up for no height/ATMOS speakers, ATMOS height content is part of what is sent to the surrounds?

If the AVR is set up for an ATMOS configuration,with height speakers, it uses the ATMOS data and sends it to the heights…
That's how I understand it.
 

sjcorne

Moderator
Staff member
Moderator
Joined
Jan 1, 2010
Messages
4,384
Location
Washington, D.C.
Am I the only one who finds - on Apple Music - the rears for Atmos mixes folded down to 5.1 to be about 3dB quieter than the rears for the true 5.1 and quad mixes?
When you run Dolby's channel ID test, do the rears seem lower in volume than the fronts?
 

marcb

600 Club - QQ All-Star
Joined
Nov 15, 2010
Messages
637
Maybe I misunderstand, but if your AVR is set up for no height/ATMOS speakers, ATMOS height content is part of what is sent to the surrounds?

If the AVR is set up for an ATMOS configuration,with height speakers, it uses the ATMOS data and sends it to the heights…
That’s my understanding as well.

But I’m wondering if maybe the ATV4K or my AVR might be doing something else.

Edit: Now that I think about it both my main system and my bedroom system (w/ a soundbar + Sub + 2 surrounds) seem to exhibit the issue, so it’s probably not the AVR.

I only put 2+2 together recently when I thought something didn’t seem right with my surrounds, so I balanced them. Then when I went to another album, they were way off in the opposite direction. Eventually I found it seemed to be an Atmos vs non-Atmos thing.
 
Last edited:

marcb

600 Club - QQ All-Star
Joined
Nov 15, 2010
Messages
637
When you run Dolby's channel ID test, do the rears seem lower in volume than the fronts?
I’ll need to try that.

But it’s not even close just listening by ear. A delta of 3-4dBs is not small. And that’s what I seem to be consistently finding with Atmos vs non-Atmos. I need to test more to make sure though.
 

RustyStatic

Senior Member
Joined
Sep 29, 2020
Messages
255
Location
Philadelphia
Finding this thread fascinating - thank you all… FWIW, I don’t have the deep technical background or understanding that many of you folks do, although I’ve been a recording musician for a few decades now and am fairly confident in my ears. But, offering a layman’s perspective, through my experiences as of late, I’ve been able to arrive at a few personal truisms:

1. I wondered if upgrading to Atmos was gonna be just snake oil or something transformative… and had to know, so I converted to a 5.2.2 by throwing some nice Focal speakers on the ceiling of my fairly small listening space. Initially using Gentle Giant’s Free Hand and The Lost Voices of Hagia Sophia discs, I immediately decided it was worth the money to upgrade and that it offered a heightened experience (pun intended 😬).

2. I absolutely can and do get a thrill out of the Atmos titles I stream from Apple TV4K, particularly the ones that are exclusive to streaming. Perfectly happy doing this.

3. However, where I’ve had the opportunity to do an A/B between Atmos discs and Atmos streaming, the discs have had a very clear advantage. This is not what I would prefer, so my confirmation bias would certainly be in the other direction. Maybe it’s a matter of fidelity, but I haven’t really been able to hear big differences there once I'm north of 16bit/44.1kHz in the past if I’m honest. Even though what’s streaming is supposed to be the same mix as what's on the discs AFAIK, it’s just not manifesting itself that way when I A/B. From a disc, the separation is just so much better and the heights are way more active and in play… so much so, that I’m kinda resigned to “if there's an Atmos mix, I’m gonna try to buy the disc if available”—which I’d rather not due to the expense.

I haven’t done extensive comparisons in the same way for 5.1 titles because for the most part I either have them on disc already, have ripped them from there and default to playing from JRiver, or if it’s a streaming quad title that never had an official digital release, that’s different enough from a conversion that I might prefer one or the other but it wouldn’t be an A/B.

Things that make you go hm.
 
Last edited:

HomerJAU

Moderator: MCH Media Players
Staff member
Moderator
Moderator
Joined
Jun 13, 2013
Messages
4,659
Location
Melbourne, Australia
There’s no doubt that lossless can sound better than lossy (lossless disc vs steaming). In my experience higher volume playback reveals this more than at low volume.

With legacy quad I’ve found some streaming quads easily sound better, especially if the conversion has come from SQ, where the fidelity and separation from the digitally encoded master (steaming) is more pleasing than from the matrix decode and conversion to digital.
 

Ephi82

Well-known Member
Joined
Jan 2, 2016
Messages
171
Location
S FL
Finding this thread fascinating - thank you all… FWIW, I don’t have the deep technical background or understanding that many of you folks do, although I’ve been a recording musician for a few decades now and am fairly confident in my ears. But, offering a layman’s perspective, through my experiences as of late, I’ve been able to arrive at a few personal truisms:

1. I wondered if upgrading to Atmos was gonna be just snake oil or something transformative… and had to know, so I converted to a 5.2.2 by throwing some nice Focal speakers on the ceiling of my fairly small listening space. Initially using Gentle Giant’s Free Hand and The Lost Voices of Hagia Sophia discs, I immediately decided it was worth the money to upgrade and that it offered a heightened experience (pun intended 😬).

2. I absolutely can and do get a thrill out of the Atmos titles I stream from Apple TV4K, particularly the ones that are exclusive to streaming. Perfectly happy doing this.

3. However, where I’ve had the opportunity to do an A/B between Atmos discs and Atmos streaming, the discs have had a very clear advantage. This is not what I would prefer, so my confirmation bias would certainly be in the other direction. Maybe it’s a matter of fidelity, but I haven’t really been able to hear big differences there once I'm north of 16bit/44.1kHz in the past if I’m honest. Even though what’s streaming is supposed to be the same mix as what's on the discs AFAIK, it’s just not manifesting itself that way when I A/B. From a disc, the separation is just so much better and the heights are way more active and in play… so much so, that I’m kinda resigned to “if there's an Atmos mix, I’m gonna try to buy the disc if available”—which I’d rather not due to the expense.

I haven’t done extensive comparisons in the same way for 5.1 titles because for the most part I either have them on disc already, have ripped them from there and default to playing from JRiver, or if it’s a streaming quad title that never had an official digital release, that’s different enough from a conversion that I might prefer one or the other but it wouldn’t be an A/B.

Things that make you go hm.
Up until recently, I wasn’t sure that I could hear a big difference between ATMOS on Blu ray vs on Apple Music/Apple TV. That got blown up when I listened to Beatles Abbey Road in both formats. The Blu Ray had much better extension and detail, heard acutely in the surrounds, and I don’t mean by a little. That said, the connivence of being able to cruise through thousands of recordings using just a little silver remote is undeniable, not to mention the fast growing number of available surround and ATMOS releases.
 

perzon57

1K Club - QQ Shooting Star
Joined
Jul 20, 2009
Messages
1,278
Location
Norway
Up until recently, I wasn’t sure that I could hear a big difference between ATMOS on Blu ray vs on Apple Music/Apple TV. That got blown up when I listened to Beatles Abbey Road in both formats. The Blu Ray had much better extension and detail, heard acutely in the surrounds, and I don’t mean by a little. That said, the connivence of being able to cruise through thousands of recordings using just a little silver remote is undeniable, not to mention the fast growing number of available surround and ATMOS releases.
And most of the Atmos releases are only on streaming, so no disc. I wouldn't miss out on all that good music in Atmos because the fidelity is a little poorer. To me it sounds quite alright. :cool:
 

Ephi82

Well-known Member
Joined
Jan 2, 2016
Messages
171
Location
S FL
Another recent discovery. I don’t know if it happened with a re boot of the Apple TV or a sw update, but my Apple TV decided that the Apple Music Audio quality should be set at the lossy level. pretty notable difference with lossless. Whatever happened to setting and forgetting?
 
Top