The Problem With Dolby Atmos

[jdbob]

I don't know about Apple TV but can try to check. I don't have Apple Music - they could perhaps be different there, though I assume it's the same mix.

It's been quite a while since I've used Tidal but I do remember some very muddy sounding Atmos mixes there. Apple supposedly has some standards regarding what they will allow for Atmos mixes, such as you can't use up-mixed stereo tracks (you must mix from stems) and there is a minimum requirement for dynamic range.

 

[Bobby Bass]

Are they any different on Apple TV? I would assume not.

I have noticed differences streaming atmos with Apple Music using Apple TV and playing atmos mixes on Blurays. Not night and day but noticeable. For example the bass was less boomy on Pink Floyd’s Animals on the Bluray as opposed to streaming. Both sound good but I find that BluRays always sound as good if not better in my experience.

 

[krabapple]

I was going to post a new thread on this topic but found this may be a good place since it most closely relates to my query.
I’m discovering more content on Apple Music lately with some of my all time favorites being remastered into Dolby Atmos - Hi-Res Lossless - Apple Digital Master.

Those are three different things, any one of which can be true.

Since configuring Apple Music to the highest possible quality in the Apple TV device settings, I have noticed a significant improvement in sound quality.
(Previously I had it in default ‘high quality’ not lossless).

Who knows what changes that makes?

With some not all content, I feel like I am missing some of what Dolby Atmos touts namely the height channels.
My HT consists of an 11.2 channel processor currently driving 7.2 channels all balanced and all active pro audio monitors/subwoofers.
I would like to implement/install the remaining 4 channels with similar active monitors effectively enabling 7.2.4.
Ideally the monitors would have the option to be safely hung from the ceiling, however, it is going to be a challenge.
I have read in some forums that ‘bouncy house’ speakers do not really work well in rendering the .4 channels.
My question is whether placing the .4 channels around the room on stands instead of from the ceiling would defeat the whole purpose and hence not a good idea?

Your question boils down to, how high above the MLP do height speakers need to be, at minimum?
Consulting the Dolby Atmos Installation Guidelines we get

The overhead speakers should be at a height (shown as H3 in Figure 2) between two and three times the vertical position of the listener-level speakers. The angle of elevation from the listening position to the left top front/right top front and left top rear/right top rear overhead speakers in a 7.1.4 reference layout should be 45 degrees. This may be adjusted between 30 and 55 degrees if needed, as shown in Figure 2. Figures 3 and 4 show the preferred locations of the four overhead speakers as seen from above. The horizontal width should be about the same as the horizontal separation of left and right speakers placed at ±30 degrees. If this guidance is followed, the overhead side-to-side separation should be 0.5 to 0.7 of the width of the overall layout, depending on the distance to the screen and the front three speakers, relative to the surrounds. It is best to keep the overhead arrangement centered, front to back, over the listening area, even if the front speakers and screen are at a greater distance than the surround speakers.

The figure may be slightly confusing, the view is from the MLP, facing directly at a side speaker:

 

[krabapple]

My understanding is you need to place those 4 speakers on the ceiling or on the wall near the ceiling depending on the height of your ceiling so they are above the base layer surround sound speakers with the speakers aimed towards the main listening position. In my 7.3.6 system I have the 6 heights mounted on the wall close to the ceiling and I hear all of the height effects in atmos music and movies.

They can be mounted on-ceiling, rather then in-ceiling. But NB regarding "on the wall near the ceiling", speakers mounted at or near the vertex of the front (or back) wall and the ceiling --aka 'Front Height' and "Back Height" -- aren't really what Dolby had in mind for the '4' of X.X.4 --, i.e., an array of 4 'overhead' speakers mounted forward of the front and rear base level speakers and inward of the side speakers..

 

[krabapple]

Some of the mixed impressions of Atmos (especially for music) are probably layout-related, not format-related.
I ran Polk OWM3 as top middle before switching to Sonance VXQ68R in the same system. The difference was noticeable.
The OWM3 is a small on-wall speaker with limited bandwidth and wide dispersion, so as a height it tends to blend with the bed layer and feels more like sound being pulled upward.
The VXQ68R is designed for in-ceiling use with more controlled dispersion and proper overhead geometry, so sounds localize above you instead of smearing upward.
Didn’t fix bad Atmos mixes, but it made it clearer which issues were the mix vs the setup.

Well, Dolby says otherwise:

Overhead speaker characteristics Dolby Atmos audio is mixed using discrete, full-range audio objects that may move around anywhere in three-dimensional space. With this in mind, overhead speakers should complement the frequency response, output, and power-handling capabilities of the listener-level speakers. Choose overhead speakers that are timbre matched as closely as possible to the primary listener-level speakers. Overhead speakers with a wide dispersion pattern are desirable for use in a Dolby Atmos system. This will ensure the closest replication of the cinematic environment, where overhead speakers are placed high above the listeners.

It would seem the reasoning here is that the system will be primarily used for movie soundtracks

 

[krabapple]

Are they any different on Apple TV? I would assume not.

The mixes themselves were not different but there was level normalizing going on with one or the other which made them sound different . IIRC Tidal presentation was much lower than Apple's, so you had to turn the Tidal up (or turn the Apple down) to get it to match.

I put this all in the past tense because I dropped Tidal after a short audition, due to this. It may have been 'corrected' since.

There are still differences between what content is offered on Apple vs Tidal, AFAIK.

 

[seashell]

My question is whether placing the .4 channels around the room on stands instead of from the ceiling would defeat the whole purpose and hence not a good idea?
I may just try it before committing to installing from the ceiling just to hear if it is worth all the effort.

You can certainly place them on stands if tall enough, and I definitely recommend it to see if it's worth it to you. I was skeptical of the benefits of top speakers vs the hassle of a ceiling install so I first put some bookshelf speakers on tall stands placed on top of old subs for extra height relatively close to my seating position. This put the speakers at roughly the correct angles elevation-wise, but definitely not perfect. (It was absolutely not a setup I would have tried with children or hyper pets, nor a long term solution with the big precarious stands in the middle of the room.)

I only did front tops for this test. I first tried movies and was for the most part not convinced it was worth it. There were a few scenes where it was neat but they were so fleeting. Then I tried atmos music mixes and was surprised how enjoyable many of them were. (There's a lot of variance, spatial mixing is definitely at the exploratory stage right now.) It was the music experience that convinced me to do a full ceiling install and for my enjoyment its definitely been worth it.

I currently have four tops, but plan to expand to six. I definitely need to move my rears further back, especially when I recline my chair. (I knew I would want to experiment with their positions and I didn't want to be limited to the locations of my ceiling joists so my tops are mounted on a gantry that gives me freedom to place the speakers basically anywhere it would make sense to place them.)

 

[krabapple]

You can certainly place them on stands if tall enough, and I definitely recommend it to see if it's worth it to you. I was skeptical of the benefits of top speakers vs the hassle of a ceiling install so I first put some bookshelf speakers on tall stands placed on top of old subs for extra height relatively close to my seating position. This put the speakers at roughly the correct angles elevation-wise, but definitely not perfect. (It was absolutely not a setup I would have tried with children or hyper pets, nor a long term solution with the big precarious stands in the middle of the room.)

I only did front tops for this test. I first tried movies and was for the most part not convinced it was worth it. There were a few scenes where it was neat but they were so fleeting. Then I tried atmos music mixes and was surprised how enjoyable many of them were. (There's a lot of variance, spatial mixing is definitely at the exploratory stage right now.) It was the music experience that convinced me to do a full ceiling install and for my enjoyment its definitely been worth it.

I currently have four tops, but plan to expand to six. I definitely need to move my rears further back, especially when I recline my chair. (I knew I would want to experiment with their positions and I didn't want to be limited to the locations of my ceiling joists so my tops are mounted on a gantry that gives me freedom to place the speakers basically anywhere it would make sense to place them.)

Height speakers firing straight forward in a plane above the listener's head isn't Dolby spec for Atmos overheads...which is firing down (with dispersion). So AIUI if they are mounted on stands, they should at least be angled down to be firing toward the listener(s), if not facing directly down.

For exactly the reason you cite in the part I bolded, I'll be installing my overheads on slidable brackets, so I can adjust them in the forward-back range.

 

[seashell]

Height speakers firing straight forward in a plane above the listener's head isn't Dolby spec for Atmos overheads...which is firing down (with dispersion). So AIUI if they are mounted on stands, they should at least be angled down to be firing toward the listener(s), if not facing directly down.

For exactly the reason you cite in the part I bolded, I'll be installing my overheads on slidable brackets, so I can adjust them in the forward-back range.

I agree the speakers should be pointed at the listening position, and debated mentioning that in my post. Certainly if the plan is to use stands as a long term solution a way of tilting the speakers down towards the listening position should be included. Any speaker review on this site will show why directivity matters, especially for non-coaxial speakers. Straight down isn't ideal either, so even in ceiling speakers should have a means of pointing the acoustic axis towards the listening position. My tops are mounted such that they are fully adjustable in both tilt and rotation so they are all aimed at the listening position. And they are fully coaxial so they have a wide sweet spot in general.

Still, if you just want to see if heights/tops are worth the hassle of an install I think speakers on stands are fine. If you hear something you like it will only be better if done correctly. If it doesn't do anything for you, i.e. you find atmos problematic in general as this thread is about, then you take it down and go on with your life. Curiosity satisfied, no further effort required.

 

[krabapple]

Straight down works depending on the dispersion characteristics of the speakers, and the content being played, and the audience.
Dolby's spec appears to be home cinema-focused and expects multiple listeners:

Overhead speakers with a wide dispersion pattern are desirable for use in a Dolby Atmos system. This will ensure the closest replication of the cinematic environment, where overhead speakers are placed high above the listeners. and its speakers all appear firing down.

For music-only sources and a single listener I can see aiming at the MLP being advisable. But I can't say until I try it. A good but likely unanswerable question would be, what was used in the mixing suite?

 

[seashell]

Straight down works depending on the dispersion characteristics of the speakers, and the content being played, and the audience.
Dolby's spec appears to be home cinema-focused and expects multiple listeners:


For music-only sources and a single listener I can see aiming at the MLP being advisable. But I can't say until I try it. A good but likely unanswerable question would be, what was used in the mixing suite?

I think about it this way, in terms of localization the sound will be coming from the speaker. If the listening position is too far off-axis the sound will be colored by the undesirable off-axis response of the speaker. I don't see why you would ever want them pointing straight down if they are not at least close to straight overhead (close is relative to the speaker's directivity). An object that moves from fronts to tops would sound different if it moved from on-axis fronts to off-axis tops even if they were identical speakers. Not an effect I would want.

Theaters can point them straight down because their ceilings are very tall (meaning the the on-axis area is large) and they usually have a large array of speakers not a single speaker anyway.

The atmos specs to me are a bit of a let down in general. The home spec is not consistent with the studio spec. The studio version specifies an angle left and right of the MLP for the tops, while the home spec just shows them inline with the fronts which can be a wide range of angles depending on distance to fronts and ceiling height. There are videos on youtube from home theater designers that discuss all this and I couldn't find a consensus on what's the right thing to do which is part of the reason I built for front/back and left/right adjustabilty. I am fortunate though that the dimenions in my room are such that 45 degrees left and right of the MLP is pretty close to inline with my front speakers so there's a natural compromise position between the home and studio specs.

Opinions differ a lot as well. I've seen the full gamut from just adding heights/tops is all that matters even if they're in the wrong positions to if you're not going to put them exactly where they should be you shouldn't use them at all. And of course "exactly where they should be" is unclear as well with the home and studio specs not matching plus any desire to compromise between atmos/dts/auro. Different people like different things and are more or less tolerant of various issues. I mean they sell atmos soundbars and are many people are happy enough with them. So in the end do what works for you.

 

[thcdru2k]

Well, Dolby says otherwise:



It would seem the reasoning here is that the system will be primarily used for movie soundtracks

Fair I definitely overstated. Even the Sonance brochure states: Each VXQ model has a uniquely designed James Quadratech tweeter and surrounding Cymatic Diffuser, the first design of its kind which creates an astonishingly clear and balanced dispersion. In my single-seat setup, switching from OWM3 to VXQ68R made heights more discrete and less smeared. No intention to knock on Dolby's wide-dispersion guidance.

 

[Bugal1998]

My 2 cents...

I’ve been comparing Dolby Atmos and stereo in a professionaly engineered and treated room with optimized speaker placement for both formats (L&R mains can be quickly repositioned), and my experience runs a bit counter to the atmos hype for music.

For music, stereo just feels more enveloping and satisfying—not because it sound surrounds you, but because it convincingly fills the room. Atmos can put sounds all around me, but stereo feels like I'm immersed and sitting in the music... like the volume of the room is completely filled. Instruments and vocals also have a stronger, more convincing presence and a cohesive presentation.

Atmos, in comparison, often sounds softer and less present. In my room, it occupies little perceived space or volume in the room. That may be a tradeoff of spreading energy across many speakers, though I’m not sure that fully explains it.

Side note, until I experienced a purpose built and professionally treated 2-channel room, I would have been strongly in camp Atmos for music. I think atmos is a great equalizer, enabling an engaging experience across a wide range of sub-optimal or even very poor rooms where stereo is dissapointing; I see that as a real strength of the technology.

The bigger issue is, I think, artistic and mixing decisions. While a few Atmos mixes make excellent use of the technology, the vast majority feel gimmicky or distracting—like a random guitar strumming on the ceiling (or whatever)—pulling attention away from the music. And to be fair, that seems more like a mixing philosophy problem than a format limitation.

For movies, though, I strongly prefer Atmos. With visuals supporting the experience, it just seems to work better. Though I still have a strong preference for ambiance-only useage in movies; pinpoint effects outside the width of the screen break immersion in the on screen world and pull my attention back into the room... for me, any useage other than ambiance seems counter productive to the intention of driving immersion.

Of course all IMHO, YMMV, etc., etc..

 

[krabapple]

Try upmixing stereo music and see how it compares.

And of course Atmos (7.x.x or higher) isn't the only surround scheme, surround consumers used 'plain old' 5.1 pretty happily for about two decades.

 

[Soundmixer]

Just a little thing I always feel the urgent need to point out. I can’t help myself, sorry.

It’s impossible to ”remaster” a stereo track into a Dolby Atmos track, but it’s possible to use the individually recorded tracks to ”remix” a song into a Dolby Atmos track.

You can actually remix a stereo track to Atmos using an AI plug-in that isolates individual instruments, elements, and voices. You don't need the individually recorded stems to do this; you just isolate and create your own mix.

 

[goat76]

You can actually remix a stereo track to Atmos using an AI plug-in that isolates individual instruments, elements, and voices. You don't need the individually recorded stems to do this; you just isolate and create your own mix.

The point I made was strictly about the terminologies remastering vs remixing. Whatever the mixing engineer does to get hold of individual tracks, whether they are the original multitracks, the original stems, or using an AI plugin to isolate individual instruments, the correct terminology is still remixing, not remastering. So again, you don't "remaster" a stereo track into an Atmos track; you remix it into an Atmos track.

And speaking of terminology, you don't record "stems" as you put it. You record individual tracks that you may later use to mix into stems. Stems are mixed stereo tracks of individual instruments that originally came from individual mono tracks.

 

[krabapple]

Try upmixing stereo music and see how it compares.

And of course Atmos (7.x.x or higher) isn't the only surround scheme, surround consumers used 'plain old' 5.1 pretty happily for about two decades.

Since we're talkin' Atmos, let me testify that having 'side' speakers -- something I was skeptical of as a 5.1 aficionado, but have now added, along with backs, to make a 7.2.x bed (no overheads yet) -- really changes the game in a good way. For true surround mixes as well as upmixes.

I was skeptical because I thought side speakers would be like headphones: not so (or only fleetingly so, depending on the mix itself).

(My sides are matched to my fronts, all speakers are arrayed <=60 degrees from speaker to speaker, modest wall panel absorption, everything calibrated by the AVR + Audyssey, in a ~12x13' room )

 

[chelgrian]

My 2 cents...

I’ve been comparing Dolby Atmos and stereo in a professionaly engineered and treated room with optimized speaker placement for both formats (L&R mains can be quickly repositioned), and my experience runs a bit counter to the atmos hype for music.

For music, stereo just feels more enveloping and satisfying—not because it sound surrounds you, but because it convincingly fills the room. Atmos can put sounds all around me, but stereo feels like I'm immersed and sitting in the music... like the volume of the room is completely filled. Instruments and vocals also have a stronger, more convincing presence and a cohesive presentation.

Atmos, in comparison, often sounds softer and less present. In my room, it occupies little perceived space or volume in the room. That may be a tradeoff of spreading energy across many speakers, though I’m not sure that fully explains it.

Side note, until I experienced a purpose built and professionally treated 2-channel room, I would have been strongly in camp Atmos for music. I think atmos is a great equalizer, enabling an engaging experience across a wide range of sub-optimal or even very poor rooms where stereo is dissapointing; I see that as a real strength of the technology.

The bigger issue is, I think, artistic and mixing decisions. While a few Atmos mixes make excellent use of the technology, the vast majority feel gimmicky or distracting—like a random guitar strumming on the ceiling (or whatever)—pulling attention away from the music. And to be fair, that seems more like a mixing philosophy problem than a format limitation.

For movies, though, I strongly prefer Atmos. With visuals supporting the experience, it just seems to work better. Though I still have a strong preference for ambiance-only useage in movies; pinpoint effects outside the width of the screen break immersion in the on screen world and pull my attention back into the room... for me, any useage other than ambiance seems counter productive to the intention of driving immersion.

Of course all IMHO, YMMV, etc., etc..

While Atmos itself has lots of technical problems the more fundamental issue is exactly people trying to create artificial sound fields in Atmos it’s similar to some of the very first stereo release where individual instruments got hard panned.

The thing is that it is very cheap to record in stereo to a standard that is acceptable to release.

Capturing an immersive sound field sufficiently well to actually make use of the direction cues is very expensive and isn’t going to get cheaper anytime soon due to the number and quality of mic capsules needed.

 

[Soundmixer]

The point I made was strictly about the terminologies remastering vs remixing. Whatever the mixing engineer does to get hold of individual tracks, whether they are the original multitracks, the original stems, or using an AI plugin to isolate individual instruments, the correct terminology is still remixing, not remastering. So again, you don't "remaster" a stereo track into an Atmos track; you remix it into an Atmos track.

And speaking of terminology, you don't record "stems" as you put it. You record individual tracks that you may later use to mix into stems. Stems are mixed stereo tracks of individual instruments that originally came from individual mono tracks.

In your effort to be pedantic, you made a small error. A stem can be one instrument, or it can be many instruments.

 

[Soundmixer]

While Atmos itself has lots of technical problems the more fundamental issue is exactly people trying to create artificial sound fields in Atmos it’s similar to some of the very first stereo release where individual instruments got hard panned.

What technical problems does Atmos have?