Playing Dolby Atmos discs on non-Atmos systems

[KeithL]

Many people ask whether they need an Atmos-enabled system to play the new Dolby Atmos discs.

THE ANSWER IS THAT NO, YOU DO NOT NEED A PROCESSOR THAT SUPPORTS DOLBY ATMOS TO PLAY AN ATMOS DISC.

According to Dolby Labs, a Dolby Atmos disc is fully backwards compatible with previous surround sound standards - including TrueHD.

Here's a quote from the Dolby Labs Atmos white paper entitled "Dolby Atmos for the Home Theater":
"Dolby Atmos audio tracks (both Dolby TrueHD and Dolby Digital Plus) are backward compatible. If you play a movie mixed in Dolby Atmos on a non Dolby Atmos system, you’ll experience traditional 5.1 or 7.1 audio, depending on the configuration of your speaker system. This means content providers don’t need to provide separate Dolby Atmos and non Dolby Atmos mixes. One mix supports both"

This also means that, unless you specifically want height channels, or more than 7.2 channels, there is no reason to "upgrade" to a processor that decodes Dolby Atmos.

[vcautokid]

Yep, completely backwards compatible. Makes you wonder if all discs this point forward will have Atmos encoding to begin with. Ah trends.

[ngmitter]

Feb 13, 2017 13:01:56 GMT -5 KeithL said:

This also means that, unless you specifically want height channels, or more than 7.2 channels, there is no reason to "upgrade" to a processor that decodes Dolby Atmos.

This is something I see mentioned a lot, but I don't know if this is a completely accurate statement. One of the key advantages to Dolby Atmos (and DTS:X), is that positional information is included. With a typical 5.1 or 7.1 audio setup, the position is hard-coded to each of the 6 or 8 channels. Meaning, it's highly dependent on your the physical location of your speakers. With Atmos, the technology should theoretically be able to better pinpoint where a particular sound is located.

I've never seen a clear explanation of Atmos in this test example:

Let's take the traditional situation. Say you have a 5.1 setup with FL, FR, C, SL, and SR.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer pans the gunshot somewhere between the center speaker and front-right speaker to approximately locate that sound.
• Depending on how wide or narrow your place your fronts, that sound may be 10 degrees, or maybe 30 degrees, or may be 15 degrees with a completely optimized setup.

Let's take the same gunshot, but on a Dolby Atmos 5.1 setup.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer no longer pans the gunshot sound effect. Instead, the processor determines the correct placement of that sound based on where your speakers are located.
• Depending on how wide or narrow your place your fronts, the processor will pan it accordingly.

Am I incorrect in this assumption of how Atmos would theoretically improve even a 5.1 setup?

[monkumonku]

Feb 13, 2017 13:38:50 GMT -5 ngmitter said:

Feb 13, 2017 13:01:56 GMT -5 KeithL said:

This also means that, unless you specifically want height channels, or more than 7.2 channels, there is no reason to "upgrade" to a processor that decodes Dolby Atmos.

This is something I see mentioned a lot, but I don't know if this is a completely accurate statement. One of the key advantages to Dolby Atmos (and DTS:X), is that positional information is included. With a typical 5.1 or 7.1 audio setup, the position is hard-coded to each of the 6 or 8 channels. Meaning, it's highly dependent on your the physical location of your speakers. With Atmos, the technology should theoretically be able to better pinpoint where a particular sound is located.

I've never seen a clear explanation of Atmos in this test example:

Let's take the traditional situation. Say you have a 5.1 setup with FL, FR, C, SL, and SR.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer pans the gunshot somewhere between the center speaker and front-right speaker to approximately locate that sound.
• Depending on how wide or narrow your place your fronts, that sound may be 10 degrees, or maybe 30 degrees, or may be 15 degrees with a completely optimized setup.

Let's take the same gunshot, but on a Dolby Atmos 5.1 setup.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer no longer pans the gunshot sound effect. Instead, the processor determines the correct placement of that sound based on where your speakers are located.
• Depending on how wide or narrow your place your fronts, the processor will pan it accordingly.

Am I incorrect in this assumption of how Atmos would theoretically improve even a 5.1 setup?

Does Atmos run some sort of program that sends signals through each speaker and a mic determines the location of the speaker? If not then I don't see how it can process anything based on where your speakers are located since it doesn't have that information.

Even if it does use a mic to determine the position of your speakers, I don't see how making sound placement that much more specific is that critical. Height, yes, but placement of objects in space no, because that would also depend on where you are sitting. Unless you sit in the same exact sweet spot where the mic was, then all the calculations will be off since it has to be done from the speakers relative to your sitting position.

[ngmitter]

Feb 13, 2017 14:23:06 GMT -5 monkumonku said:

Does Atmos run some sort of program that sends signals through each speaker and a mic determines the location of the speaker? If not then I don't see how it can process anything based on where your speakers are located since it doesn't have that information.

As I was typing my initial response, that the thought I had in my mind. I didn't think position was determined anywhere during the Audyssey calibration process or anywhere else in the receiver setup.

It seems like you can potentially get much more accurate sound if it did take advantage of this. For movies, it may not matter much, but I'd imagine a video game like a first person shooter could benefit from it.

[Bonzo]

So this thread is basically the definitive answer to what I was asking here the other week. Right Keith? Cool.

emotivalounge.proboards.com/thread/49276/technical-question-regarding-backwards-compatibility

And what we found out in my thread was that in my case it was the particular movie to blame. "Pets" is mixed so that there is very little surround information regardless of what your system is capable of. But it's especially lacking if you only have Dolby True or DTS Master with side/back WALL surround speakers. There is very little information sent out through those speakers. The net result is a movie that sounds more like Dolby Digital 3.1, or even 3.0.

[KeithL]

You're entirely correct in your analysis of the process involved - but incorrect in your conclusions.

You are entirely correct that, in the Dolby TrueHD mix, made by the mixing engineer to work properly with speakers in the standard positions, the apparent location of that gunshot will depend on the relative levels and time delays in the various channels, and will have been "immovably mixed" for the standard layout. And you are also correct that, in the Atmos mix, the location of those gunshots will be stored as positional information, which may then be used by the Atmos decoder to accurately locate them. You are also correct that, IF YOUR SPEAKERS WERE IN NON-STANDARD LOCATIONS OR YOU HAD ADDITIONAL SPEAKERS, this would enable the Atmos decoder to position those sounds to come from the proper apparent locations anyway. However, if you have a standard surround sound setup, AND YOU DON'T HAVE CEILING OR HEIGHT SPEAKERS, the recommended speaker locations for your front, center, and surround speakers are the same for an Atmos system or a Dolby TrueHD system.  Therefore, since your speakers will be in the same locations, the results will be the same.

(When you set up your system for Atmos, speaker distances are entered or measured, but the processor does NOT figure out the locations of the speakers; it simply expects each speaker to be in the standard location. Because of this, Atmos is NOT able to accommodate unusual speaker locations, or to calculate more accurate positions for individual objects if your speakers are in unusual positions. It simply assumes your speakers are in the standard positions, which is exactly the same assumption the mixing engineer uses to position things in the TrueHD mix...... )

Feb 13, 2017 13:38:50 GMT -5 ngmitter said:

Feb 13, 2017 13:01:56 GMT -5 KeithL said:

This also means that, unless you specifically want height channels, or more than 7.2 channels, there is no reason to "upgrade" to a processor that decodes Dolby Atmos.

This is something I see mentioned a lot, but I don't know if this is a completely accurate statement. One of the key advantages to Dolby Atmos (and DTS:X), is that positional information is included. With a typical 5.1 or 7.1 audio setup, the position is hard-coded to each of the 6 or 8 channels. Meaning, it's highly dependent on your the physical location of your speakers. With Atmos, the technology should theoretically be able to better pinpoint where a particular sound is located.

I've never seen a clear explanation of Atmos in this test example:

Let's take the traditional situation. Say you have a 5.1 setup with FL, FR, C, SL, and SR.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer pans the gunshot somewhere between the center speaker and front-right speaker to approximately locate that sound.
• Depending on how wide or narrow your place your fronts, that sound may be 10 degrees, or maybe 30 degrees, or may be 15 degrees with a completely optimized setup.

Let's take the same gunshot, but on a Dolby Atmos 5.1 setup.

• Assume the sound effect is a gunshot.
• The gunshot is intended to come out at 15 degrees from the right of screen center.
• The sound engineer no longer pans the gunshot sound effect. Instead, the processor determines the correct placement of that sound based on where your speakers are located.
• Depending on how wide or narrow your place your fronts, the processor will pan it accordingly.

Am I incorrect in this assumption of how Atmos would theoretically improve even a 5.1 setup?

[ngmitter]

Thanks for the explanation, KeithL! Very useful info.

I wonder how hard it would be to have a GUI to program in the speaker angles from the listening position. Probably overkill for 99.9% of home theaters, but unfortunately many of us are at the mercy of the room layout when positioning speakers.

[KeithL]

1)  The GUI itself would require significant programming.
2) It would require the user to enter a lot more information.
3) The calculations themselves would be a lot more complicated and require a lot more computing power.
4) You'd have to deal with validation (some setups simply wouldn't work - imagine someone with seven speakers, all on the left side of the room).
        (So you'd need to add the complexity to evaluate the room setup and warn the user when they chose one that just couldn't be made to work well.)

After all that you're probably approaching the cost, complexity, and setup effort of the full theater version.

Feb 13, 2017 15:22:56 GMT -5 ngmitter said:

Thanks for the explanation, KeithL! Very useful info.

I wonder how hard it would be to have a GUI to program in the speaker angles from the listening position. Probably overkill for 99.9% of home theaters, but unfortunately many of us are at the mercy of the room layout when positioning speakers.

[KeithL]

Using one microphone you can measure the distance from the measurement point to each speaker, but not position in 3D space (or angular position).
(If you could use multiple microphones at the same time, you could take multiple readings and triangulate - but NOBODY does THAT. )

Automatic room correction systems measure delay (or "acoustic distance") - but they don't measure actual physical position in space.
That would require you to manually enter the position of each speaker on some sort of GUI - like a 3D drawing program.
The only alternative would be if each speaker included some way to locate itself relative to its brethren and report its position to the processor.
People have tried this in the past but I haven't heard anyone claiming to use it for an Atmos or DTS-X system.

Feb 13, 2017 14:23:06 GMT -5 monkumonku said:

Does Atmos run some sort of program that sends signals through each speaker and a mic determines the location of the speaker? If not then I don't see how it can process anything based on where your speakers are located since it doesn't have that information.

Even if it does use a mic to determine the position of your speakers, I don't see how making sound placement that much more specific is that critical. Height, yes, but placement of objects in space no, because that would also depend on where you are sitting. Unless you sit in the same exact sweet spot where the mic was, then all the calculations will be off since it has to be done from the speakers relative to your sitting position.

[aviolentgrace]

As an aside, this is a pretty cool overview of the benefits, with hints as to the process. (I love the sound object visualizer in the background... talk about the future of the spectrum analyzer!)

vimeo.com/142305230

[405x5]

Feb 13, 2017 13:01:56 GMT -5 KeithL said:

Many people ask whether they need an Atmos-enabled system to play the new Dolby Atmos discs.

THE ANSWER IS THAT NO, YOU DO NOT NEED A PROCESSOR THAT SUPPORTS DOLBY ATMOS TO PLAY AN ATMOS DISC.

According to Dolby Labs, a Dolby Atmos disc is fully backwards compatible with previous surround sound standards - including TrueHD.

Here's a quote from the Dolby Labs Atmos white paper entitled "Dolby Atmos for the Home Theater":
"Dolby Atmos audio tracks (both Dolby TrueHD and Dolby Digital Plus) are backward compatible. If you play a movie mixed in Dolby Atmos on a non Dolby Atmos system, you’ll experience traditional 5.1 or 7.1 audio, depending on the configuration of your speaker system. This means content providers don’t need to provide separate Dolby Atmos and non Dolby Atmos mixes. One mix supports both"

This also means that, unless you specifically want height channels, or more than 7.2 channels, there is no reason to "upgrade" to a processor that decodes Dolby Atmos.

Hi Keith,

Well, here we are in September.
Just chiming in as an "end user", to agree 7 months after this thread started up, that my growing collection of ATMOS DISCS....(NOT why I bought them,) play beautifully on my somewhat unconventional surround sound system with the XMC-1 being the nerve center. Skull 💀 Island was the last picked up title.

I live a one hour train ride from what many consider to be the entertainment capital of the world.....and now several years down the pike, the only way I can be reasonably SURE I'm hearing a properly done ATMOS presentation.
Is to get on that train, and get to a NYC movie house.

I just looked to see what's here in the way of threads regarding object based audio and I see only three (including this one)
All three have been dead for the most part.

Don't mind me.... I'm just kind of rambling in a somewhat deliberate way.
While waiting in 2014 to take delivery on one of the early production units if the XMC, the introduction of ATMOS and who ( Marantz, Yamaha, etc.) would have it on board was feeling to me like sabotage.
I felt bad for you guys, as if there wasn't enough to be concerned with, while getting that beautiful XMC 1 out there.

Periodically, I jump on the internet, trying to acquire some really good, usable information on how well Atmos may be doing at home, but it's a chore, still to come up with much.

4K, well that's another story.

Bill

[Gary Cook]

Feb 13, 2017 15:19:25 GMT -5 KeithL said:

(When you set up your system for Atmos, speaker distances are entered or measured, but the processor does NOT figure out the locations of the speakers; it simply expects each speaker to be in the standard location. Because of this, Atmos is NOT able to accommodate unusual speaker locations, or to calculate more accurate positions for individual objects if your speakers are in unusual positions. It simply assumes your speakers are in the standard positions, which is exactly the same assumption the mixing engineer uses to position things in the TrueHD mix...... )

Recently I was at our local theatre complex and the sound guy was setting up / checking one of the few Atmos enabled theatres with a number of microphones that looked like these;




I understand that they provide tridimensional speaker localisation, which possibly indicates that it is possible to account for non standard Atmos speaker locations?


Cheers
Gary

[simpleman68]

Sept 6, 2017 18:37:12 GMT -5 Gary Cook said:

Feb 13, 2017 15:19:25 GMT -5 KeithL said:

(When you set up your system for Atmos, speaker distances are entered or measured, but the processor does NOT figure out the locations of the speakers; it simply expects each speaker to be in the standard location. Because of this, Atmos is NOT able to accommodate unusual speaker locations, or to calculate more accurate positions for individual objects if your speakers are in unusual positions. It simply assumes your speakers are in the standard positions, which is exactly the same assumption the mixing engineer uses to position things in the TrueHD mix...... )

Recently I was at our local theatre complex and the sound guy was setting up / checking one of the few Atmos enabled theatres with a number of microphones that looked like these;




I understand that they provide tridimensional speaker localisation, which possibly indicates that it is possible to account for non standard Atmos speaker locations?


Cheers
Gary

Now that looks cool. Would be great to be able to incorporate added dimensional measurements to a theater.
Scott

[creimes]

What about playback of an Atmos disc in my Beta machine, still backwards compatible

[creimes]

Sept 6, 2017 20:43:04 GMT -5 simpleman68 said:

Sept 6, 2017 18:37:12 GMT -5 Gary Cook said:

Recently I was at our local theatre complex and the sound guy was setting up / checking one of the few Atmos enabled theatres with a number of microphones that looked like these;




I understand that they provide tridimensional speaker localisation, which possibly indicates that it is possible to account for non standard Atmos speaker locations?


Cheers
Gary

Now that looks cool. Would be great to be able to incorporate added dimensional measurements to a theater.
Scott

Looks like the mic i received with my XMC-1, maybe only the pre-order list came with those "special" mic's hahaha

[hemster]

Sept 6, 2017 20:51:53 GMT -5 creimes said:

What about playback of an Atmos disc in my Beta machine, still backwards compatible

Soooo, you're the one that has the only remaining Betamax machine in the world!  

[creimes]

Sept 6, 2017 20:54:07 GMT -5 hemster said:

Sept 6, 2017 20:51:53 GMT -5 creimes said:

What about playback of an Atmos disc in my Beta machine, still backwards compatible

Soooo, you're the one that has the only remaining Betamax machine in the world!  

Well of course, I also still have a copy of ET on betamax lol

[Loop 7]

You are all wrong!

Playing an Atmos Blu-ray disc voids the warranty on both your non-Atmos capable player and the disc. There have been numerous reports of players igniting into flames and discs emitting a toxic gas.

Go ahead and try it but, if something goes wrong, you can only blame yourself for throwing caution to the wind.

[audiogeek]

I still have my old Beta HiFi (top of the line Sony that I paid way too much for back in the mid 80s)