Atmos/DTS:X height channel physical placement in an old house...

[polmuaddib]

Auro cannot use Atmos metadata, but it can adapt (not upmix) a Dolby Atmos track to its speaker set up.

Thanks.
But if you turn on Auro 3D on AVR and select an audio track which contains dolby Atmos ( which is either dolby trueHD or dolby digital) Auro is just gonna use the bed channels of that track? Right? Whatever height channels will be playing is gonna be Auro’s processing and not native Atmos content?

 

[Nathan Raymond]

Thanks.
But if you turn on Auro 3D on AVR and select an audio track which contains dolby Atmos ( which is either dolby trueHD or dolby digital) Auro is just gonna use the bed channels of that track? Right? Whatever height channels will be playing is gonna be Auro’s processing and not native Atmos content?

Great question. Back in 2018 Dolby sent a private memo to their licensee partners to restrict upmixing of non-native Dolby content, but it was withdrawn after Xperi (owner of DTS) took the issue up with the European Commission:

https://www.audioholics.com/audio-t...cting-non-native-upmixing-a-win-for-consumers

Presumably this frees up DTS and Auro to upmix Atmos to speaker configurations that Dolby doesn't support. I can't seem to find any hard info that Auro 3D upmixing will use anything more than the 5.1 or 7.1 bed track. Lots of anecdotes from people saying they prefer a 5.1/7.1 bed track upmixed to Auro 3D over a native Dolby Atmos track for a lot of movies (which doesn't make a lot of sense to me, but it's something I have zero experience with, and nothing I own has an Auro decoder).

An old 2018 upmixing comparison done on a Denon AVR-X8500H talks about some of the differences in upmixing and how they can use (and not use) certain speaker layouts:

https://www.highdefdigest.com/blog/dolby-dts-auro-surround-sound-upmixer-comparison/

That post makes some claims about both how upmixing works with top speakers and height speakers:

After installing the X8500H, I configured the receiver for 7.1.6 format, designating my three pairs of height speakers as Front Height, Top Middle, and Rear Height respectively. Then I performed an Audyssey calibration to adjust the volume levels and apply EQ.

Of the three upmixers, only DSU utilizes all three height pairs. Both Neural:X and Auro-3D are limited to 7.1.4 processing, ignoring the Top Middle speakers. (Auro-3D can be configured for 5.1.6, but I did not test that this time through.) On the other hand, although it fills more speakers with sound, DSU only actually decodes height information as a single stereo signal, using the entire left side of the room (all speakers) as one channel and the entire right side of the room as the other, with no distinction between front and rear. (Note that this only applies to DSU upmixing, not to native Dolby Atmos soundtracks, which have fully discrete sound from every speaker.) In their favor, both Neural:X and Auro-3D have four distinct upmixed height channels, front and rear on both the left and right.

Note that his description of how native Dolby Atmos sounds on 7.1.6 setup with front height, top middle, and rear height being discrete contradicts what people have been saying about how height channels work earlier in this thread, where people have said that with native Dolby Atmos non-top (i.e. wall mounted) height channels will produce the wrong sound (sound intended for top/ceiling mounted speakers), so it could be that the blog post is flawed, or that there are some details missing somewhere.

 

[Nathan Raymond]

Of course i understand that, but i am really certain that it is not necessarily matter of money, you could get very good second hand overhead speakers for a few dollars literally, if you decide that this is the way to go. You can do amazing system for a very limited budget, if you do it right.
And you can also do absolutelly terrible one, and spent hunderts of thousands.
Your Denon AVR-X3700H is not only supporting four overhead speakers, but it is also ultimate, almost miraculous bargain for the money.
I will gladly try to find some directions for you to demonstrate my point, just show some existing setup pictures, and perhaps a simple floorplan with the positions, if you want.

Thanks. I'll take some pictures and provide the floorplan. I'd appreciate any thoughts people might share.

 

[Soundmixer]

Note that his description of how native Dolby Atmos sounds on 7.1.6 setup with front height, top middle, and rear height being discrete contradicts what people have been saying about how height channels work earlier in this thread, where people have said that with native Dolby Atmos non-top (i.e. wall mounted) height channels will produce the wrong sound (sound intended for top/ceiling mounted speakers), so it could be that the blog post is flawed, or that there are some details missing somewhere.

He like everyone else is conflating height with top, and they are not the same. The X8500 has provisions for three sets of top speakers. Front top, middle top, and rear top. It also supports front and rear heights for Auro3D. You cannot choose the front or rear heights (as in Auro) with the top middle (as in DSU), it won't work. His configuration uses three pairs of top speakers just like mine does. Also, this is old as DTS:X pro does support top middle with both X and Neural X on the 8500. I also have the X8500.

 

[Soundmixer]

Well, that seems strange to me, because onyl two pair of overheads at least are allowing the Atmos decoder to position and move sound sources above your head, and it is doing so a lot. You simply can´t make for example airplane effect flying above you from behind to the front. I think that the issue of four overhead channels causing problems that you are mentioning could be perhaps mainly caused by too wide radiation patterns of the speakers used in the setup, wrong positioning and lack of absorbtion materials in the room?

This is incorrect. Atmos will use whatever amount of speakers it needs to position the object where it needs to be. A front-to-back flyover would be interpreted as follows. It starts in the front speakers, then will rise upwards halfway in between the fronts and the tops equal volume (a phantom image), then fully to the top, and then half mixed between the rears and the tops equal volume (another phantom image), and then to the rears discretely. In my room, I can definitely hear a top front and a top rear phantom image between my front and rear speakers, and the tops.

The problem with using four overheads in a very small room is there is not sufficient distance between the speakers. They sound blended together when they should be discrete. It is not positioning, and it is not the dispersion pattern. They are just too close together, so they muddle and blend everything together.

 

[Adam Bernau]

This is incorrect. Atmos will use whatever amount of speakers it needs to position the object where it needs to be. A front-to-back flyover would be interpreted as follows. It starts in the front speakers, then will rise upwards halfway in between the fronts and the tops equal volume (a phantom image), then fully to the top, and then half mixed between the rears and the tops equal volume (another phantom image), and then to the rears discretely. In my room, I can definitely hear a top front and a top rear phantom image between my front and rear speakers, and the tops.

The problem with using four overheads in a very small room is there is not sufficient distance between the speakers. They sound blended together when they should be discrete. It is not positioning, and it is not the dispersion pattern. They are just too close together, so they muddle and blend everything together.

Yes, i know that the object positioning that the decoder/processor does is trying to reconstruct the ideal positions and movements in the matrix with any number and any positions of the speakers, but as we know that our brain is actually creating the effect of recognition of sound sources in the space above, on the sides and behind, which are being received only with our two ears, via autonomous very fast processing algorithms, deciding upon the perception of space that is based mostly in the delays and reflections in the soundfield.
So i really don´t think that you can sucesfully create the same effect, as having the upper tops, because the main stereo pair is already recognised by the brain as being in front, and is continuously playing sounds that belong in the front part of the soundbed, if you get my meaning.
To be sure we should perhaps make an experiment in already properly set and working Atmos installation with four overheads.
I have perhaps every Atmos and True HD demo possible, but what i am missing is any demo disc, device or app, that would actually allow you to test in your installation how well is your system reproducing the mix. Do you know about such thing perhaps?
PS in very small rooms the thing that you are saying might be true, honestly i have never installed or heard Atmos in a "very small" room..
I am currently working on my smallest listening room right now (12 square meters, so very small and hopefully fitting your description), and i have already done the wiring for 5.1.4, so i will let you know soon

 

[Adam Bernau]

Thanks. I'll take some pictures and provide the floorplan. I'd appreciate any thoughts people might share.

Yes, that would be perhaps for the best, and also the only way to be certain what is and what is not possible in your room

 

[Soundmixer]

Yes, i know that the object positioning that the decoder/processor does is trying to reconstruct the ideal positions and movements in the matrix with any number and any positions of the speakers, but as we know that our brain is actually creating the effect of recognition of sound sources in the space above, on the sides and behind, which are being received only with our two ears, via autonomous very fast processing algorithms, deciding upon the perception of space that is based mostly in the delays and reflections in the soundfield.

I think both Dolby and DTS know this, and by the way, so do I!

So i really don´t think that you can sucesfully create the same effect, as having the upper tops, because the main stereo pair is already recognised by the brain as being in front, and is continuously playing sounds that belong in the front part of the soundbed, if you get my meaning.

When it comes to height fronts and rears, I agree with you. When stacking one speaker on top of the other (Auro3D), you are not creating new spatial points in space, you are enhancing what is already there (the 5.1 speaker setup).

I have perhaps every Atmos and True HD demo possible, but what i am missing is any demo disc, device or app, that would actually allow you to test in your installation how well is your system reproducing the mix. Do you know about such thing perhaps?

If you already have every Atmos demo possible, then there is no need to ask this question. The Atmos and DTS:X demo discs in your collection (if you have them) are the best tests you can get to demo Atmos and X.

 

[Dj7675]

Anytime you forgo the ceiling speakers in favor of front and rear height speakers, you will compromise Atmos. You will also compromise X as no movie has been mixed in this format with height speakers. The only way to support all of the formats is to set up two completely different speakers setups and integrate them into one system. My brother's system (he uses the Altititude32 processor) does this.

While a bit late replying, I wanted to thank you for sharing your thoughts/experience on Atmos placement. It gave me something to thing about. With a Denon X8500 I had FH/TM/TR speakers. Front height were around 20-25 degrees above the screen, Top Middle were around 80-85 degrees and top rear were around 45 degrees behind. This worked pretty well but the FH never really felt above like I thought they should. I simplified and just went Top Front at 40-45 deg in front and top middle 40-45 deg behind. Not content above feels on above you and there is a nice phantom image between. I may at some point go back to 6 tops speakers, but some content has the Top middle speakers silent that is hard coded 7.1.4, so not having TM for now is the easiest solution. So thanks for sharing that. I think your point was, yes you can configure your system with front height/rear height but at the lower angles it won’t be quite right as configured per Dolby specs with tops as it is created...And I would agree with that from changing my system around recently.
On your system with 6 tops, do you find content that is hard coded as 7.1.4 an issue with the TM being silent causing a gap/dead spot?

 

[jhaider]

More BS here. This is not about room volume, it is not about the surround speakers, it is about where the immersive speakers are placed. Let's be clear about that.

Sigh. What part of "wrong room" is stuck somewhere between your eyes and your brain?

Interesting supposition, but also incorrect. Let me correct you. Human discrimination of height from sound isn't nearly that precise OUTDOORS. Indoors with speakers placed overhead, and your hypothesis breaks down completely, as Atmos wouldn't work if you were correct. I assure you you can tell what is flying over your head from left to right, front to back, in circles, and even diagonally with Atmos. Just get the Atmos demo disc, and it highlights all of this.

I have both Atmos demo disks. I have auditioned them using my Auro-style height speaker setups (current and former). They execute these effects just fine, and much better than bouncey-whatevers. Which I have also tried. Have I compared them to height speakers arrayed in a little box above the couch? No, because that layout does not make practical sense in most actual humans' living rooms, ours included.

For all your fundie puffery one can only infer from these comments that you've never actually experienced this program with heights positioned per Auro specs. I don't fault you for that. Immersive setups are rare generally - and made rarer when people on the internet spew rigid dogmatic nonsense, which may have the effect of dissuading people interested in immersive from even trying - and I expect hybrid Auro/Atmos setups are even rarer. Frankly I only even know of two: Dr. Toole's and ours. I'm sure there are others of course. But when you don't know what you're talking about it's better not to talk. I recommend seeking out such a system before shoving your foot deeper down your throat. Or you can keep going Taliban on everyone with this fundamentalist nonsense. I'm going to listen to some music, either native Atmos on Apple Music or upmixed from 2-channel using Auro.

 

[kos999]

What is the minimum distance between front and back Atmos in wall ceiling speakers?

 

[Adam Bernau]

What is the minimum distance between front and back Atmos in wall ceiling speakers?

Here you go. Basically the (four) ceiling speakers should form a square above your head, which is in the center of it. The recommended angles are included in the brochure.

5.1.4 Overhead Speaker Setup

Learn how to set up Dolby Atmos 5.1.4 overhead speakers for an immersive Dolby Atmos experience. Get professional tips and guidance for optimal speaker placement.

www.dolby.com

 

[pedrob]

Based on my reading, I have reservations about using speakers that don't attempt to have an Atmos target curve in the upfiring/bounce role. For instance, take a look at Archimago's review and measurements of the ELAC Debut 2.0 A4.2 Atmos Speakers:

https://archimago.blogspot.com/2021/01/measurements-elac-debut-20-a42-atmos.html

Specifically:



The more I think about this, the safe bet is to use my bookshelf speakers as "Front height speaker left/right". Denon's manual has this suggestion for FHL/FHR placement: "Place the FRONT HEIGHT left and right speakers directly above the front speakers. Mount them as close to the ceiling as possible and aim them towards the main listening position." I assume the reason for pointing them to the listener is to improve the frequency response the listener hears across the spectrum by keeping the speaker as on-axis as possible and to reduce unnecessary reflections off the ceiling.

So maybe I should use some rare earth magnets to determine if there are studs in the right places in line behind my front left and right speakers, then see if I can find angle speaker mounts that only need two screws so I can mount them to the studs. I realize I have another speaker option at hand - a pair of Infinity Primus P143 two way bookshelf speakers. A bit smaller (4" main driver), also front ported, with an important advantage - threaded socket in the middle so they could mounted to an angle bracket very easily and neatly. Maybe that would be the best option?

Nathan, can you help me with a conundrum?

I note the frequency response for Atmos approved speakers. What happens if I use conventional speakers with a flat response instead of approved Atmos speakers with that odd proprietary curve, which was likely only incorporated to create uniqueness, so the necessary patents would be approved? Would I need a notch filter to remove the almost 5dB peak around 7-8 kHz? Is my Denon outputting a modified response as it is expecting Atmos approved speakers?

 

[Nathan Raymond]

Nathan, can you help me with a conundrum?

I note the frequency response for Atmos approved speakers. What happens if I use conventional speakers with a flat response instead of approved Atmos speakers with that odd proprietary curve, which was likely only incorporated to create uniqueness, so the necessary patents would be approved? Would I need a notch filter to remove the almost 5dB peak around 7-8 kHz? Is my Denon outputting a modified response as it is expecting Atmos approved speakers?

Good question... this is something I've thought about, and I can certainly share what I know and my experiences. I'm currently running a pair of Wharfedale D300 Surround speakers for my Atmos speakers, and while they aren't specifically listed as "Atmos" speakers, Wharfedale describes them thus: "Designed to sit at the perfect angle, the D300 3D SURROUND will offer the added dimension of height and reflect sound off the ceiling for the third-dimension in-home theatre experiences." I don't have have an easy way to do A-B testing of Atmos speakers, but in my experience the D300 Surround have performed well - keeping in mind that I do use the Audyssey MultEQ XT32 built into the receiver. I figure whether the speakers come with the Atmos curve or not, Audyssey should be correcting pretty well for whatever response the speakers are creating in my space.

Over at AVS Forum, they have an Audyssey FAQ, and one of the questions is, "Will Audyssey work properly with Atmos-enabled speaker designs?" to which they provide this answer:

'Atmos-enabled' speakers or modules work by 'beaming' height content at the ceiling and allowing it to be reflected from it. The issue is whether Audyssey will 'see' this reflected content for what it is - intended content - or whether it will 'see' it as unwanted reflections which should be suppressed if possible.

Atmos-enabled speakers work by using a special, top-mounted speaker driver, designed specifically to have narrow directivity and to suppress forward-firing 'leakage' of the sound intended to hit the ceiling. This is coupled with special DSP inside an Atmos-enabled AVR which further suppresses any unintended leakage of forward content. All who have heard this system say it works remarkably well.

Given that, Audyssey should 'see' only the reflected content as its sound wave hits the Audyssey mic and one would therefore expect Audyssey to be able to handle this as though the sound was originating from a 'real' ceiling speaker. If that is the case, then Audyssey should be able to calibrate the Atmos-enabled speaker just as it does any other speaker in the system. At this time, no further information is available.

(Note: This answer is applicable at 30 July 2014 and will be updated as more Dolby Atmos information becomes available.)

I hope this helps.

 

[pedrob]

Good question... this is something I've thought about, and I can certainly share what I know and my experiences. I'm currently running a pair of Wharfedale D300 Surround speakers for my Atmos speakers, and while they aren't specifically listed as "Atmos" speakers, Wharfedale describes them thus: "Designed to sit at the perfect angle, the D300 3D SURROUND will offer the added dimension of height and reflect sound off the ceiling for the third-dimension in-home theatre experiences." I don't have have an easy way to do A-B testing of Atmos speakers, but in my experience the D300 Surround have performed well - keeping in mind that I do use the Audyssey MultEQ XT32 built into the receiver. I figure whether the speakers come with the Atmos curve or not, Audyssey should be correcting pretty well for whatever response the speakers are creating in my space.

Over at AVS Forum, they have an Audyssey FAQ, and one of the questions is, "Will Audyssey work properly with Atmos-enabled speaker designs?" to which they provide this answer:


I hope this helps.

It seems like you've made a great speaker choice, particularly if all your speakers are from the same D300 series. Something that I decided to do. Unfortunately, I am still uncertain, as I prefer to turn Audyssey off.

 

[pedrob]

I received an answer from SVS that might be helpful. If correct, the Denon would output a flat frequency response.

"The only Dolby Atmos certified speakers are the up-firing ceiling-bounce style. The Dolby Atmos spec for this type of speaker requires crossover and baffle modifications to generate a specific FR designed to convince the listener the speaker sound is coming from the ceiling. Even under the best of conditions, this technology remains unconvincing in our opinion - and SVS has never offered an up-firing ceiling-bounce speaker for this reason. In comparison, the Prime Elevation is a direct-firing speaker which has a flat and accurate frequency response and delivers a far more immersive and convincing height effects experience. Prime Elevation can be used for side surround, rear surround and overhead height applications. With its 2-piece integral speaker bracket and ceiling safely lock, Prime Elevation can be mounted on the side walls, rear wall and on the ceiling. Ed M - SVS"

The manual (page 7) for their Prime Elevation suggests 24" minimum elevation above the listener's ears when mounted on a wall is all that's needed.

 

[Soundmixer]

Well, that seems strange to me, because onyl two pair of overheads at least are allowing the Atmos decoder to position and move sound sources above your head, and it is doing so a lot. You simply can´t make for example airplane effect flying above you from behind to the front. I think that the issue of four overhead channels causing problems that you are mentioning could be perhaps mainly caused by too wide radiation patterns of the speakers used in the setup, wrong positioning and lack of absorbtion materials in the room?

Yes, you can make an airplane fly from front to back with just two overhead speakers. The metadata will use the front, overhead, and rear speakers to move the plane overhead. Keep this in mind. Atmos will use whatever speakers it needs to position the object at the right coordinate(s). Aside from that, most flyovers don't happen only in the overhead speakers. With all of the tracks I have mastered and encoded, most flyovers start in the front channels, not the overhead front. With only 30 degree

The problem I had with 4 overhead speakers in that small of a room was that it sounded like mush, and there was not enough distance between the overhead speakers for any convincing overhead movement. When the 4 speakers were placed according to Dolby's standards, the front top speakers ended up over the front speakers, and the same for the rear top speakers; they ended up over the rear speakers. That is not the proper alignment for Atmos, but it would work well for Auro. It had nothing to do with speaker radiation patterns, and the room is properly treated; the room was just too small to accommodate 4 overhead speakers properly.

 

[Soundmixer]

Sigh. What part of "wrong room" is stuck somewhere between your eyes and your brain?



I have both Atmos demo disks. I have auditioned them using my Auro-style height speaker setups (current and former). They execute these effects just fine, and much better than bouncey-whatevers. Which I have also tried. Have I compared them to height speakers arrayed in a little box above the couch? No, because that layout does not make practical sense in most actual humans' living rooms, ours included.

For all your fundie puffery one can only infer from these comments that you've never actually experienced this program with heights positioned per Auro specs. I don't fault you for that. Immersive setups are rare generally - and made rarer when people on the internet spew rigid dogmatic nonsense, which may have the effect of dissuading people interested in immersive from even trying - and I expect hybrid Auro/Atmos setups are even rarer. Frankly I only even know of two: Dr. Toole's and ours. I'm sure there are others of course. But when you don't know what you're talking about it's better not to talk. I recommend seeking out such a system before shoving your foot deeper down your throat. Or you can keep going Taliban on everyone with this fundamentalist nonsense. I'm going to listen to some music, either native Atmos on Apple Music or upmixed from 2-channel using Auro.

"I have both Atmos demo disks. I have auditioned them using my Auro-style height speaker setups (current and former). They execute these effects just fine, and much better than bouncey-whatevers. Which I have also tried. Have I compared them to height speakers arrayed in a little box above the couch? No, because that layout does not make practical sense in most actual humans' living rooms, ours included."

It may have executed the effects "just fine", but did it execute it accurately? That is the question. It may have played them, but were the objects in the right place? I would say no. If you have never tried overheads (which is the proper way to playback Atmos), then you don't know what the proper tracking of objects sounds like.

"For all your fundie puffery one can only infer from these comments that you've never actually experienced this program with heights positioned per Auro specs."

Your inference would be inaccurate. Never assume something, just ask.

"Immersive setups are rare generally - and made rarer when people on the internet spew rigid dogmatic nonsense, which may have the effect of dissuading people interested in immersive from even trying - and I expect hybrid Auro/Atmos setups are even rarer. Frankly I only even know of two: Dr. Toole's and ours. I'm sure there are others of course. But when you don't know what you're talking about it's better not to talk"

Just enhance your calm, you are sounding overly emotional and full of assumptions. Atmos has set up rules. I didn't make them up. They are there for a reason, and when you stray away from the rules(speaker setup in this case), you are not going to get the accurate results from Atmos. What you call dogma is called proper guidelines to get the best result. Just because you can't do it, does not mean it is dogma. You just can't do it, and that is that.

"I recommend seeking out such a system before shoving your foot deeper down your throat"

I have a recommendation of my own. Before you assume somebody hasn't done something, why not just ask? That is what intelligent people do. Assumptions are never good, because they make you look like the first three letters.

 

[Alice of Old Vincennes]

While a bit late replying, I wanted to thank you for sharing your thoughts/experience on Atmos placement. It gave me something to thing about. With a Denon X8500 I had FH/TM/TR speakers. Front height were around 20-25 degrees above the screen, Top Middle were around 80-85 degrees and top rear were around 45 degrees behind. This worked pretty well but the FH never really felt above like I thought they should. I simplified and just went Top Front at 40-45 deg in front and top middle 40-45 deg behind. Not content above feels on above you and there is a nice phantom image between. I may at some point go back to 6 tops speakers, but some content has the Top middle speakers silent that is hard coded 7.1.4, so not having TM for now is the easiest solution. So thanks for sharing that. I think your point was, yes you can configure your system with front height/rear height but at the lower angles it won’t be quite right as configured per Dolby specs with tops as it is created...And I would agree with that from changing my system around recently.
On your system with 6 tops, do you find content that is hard coded as 7.1.4 an issue with the TM being silent causing a gap/dead spot?

Be careful responding to old thread. A " moderator" chastised me for such "antics.". Pathetic.

 

[Dj7675]

Be careful responding to old thread. A " moderator" chastised me for such "antics.". Pathetic.

I don’t understand…. I didn’t respond recently. Mine was in 2021…