Dolby atmos

Steve84

Novice Member
Hi
I have only got a 5.1 surround system and most films that are capable of it seem to automatically play Dolby atmos which I thought you needed 7.1 for. My question am I getting a poorer sound scape leaving it as atmos as opposed to changing it to a different setting or is atmos still the best version even through 5.1 set up
 

John7

Well-known Member
That is strange. It would indicate your receiver is set up wrong if it is switching/allowing Atmos to be activated?

What is your equipment (make/model)?
 

dante01

Distinguished Member
Atmos is fascilitated by the inclusion of metadata packaged with Dolby Digital Plus or Dolby TrueHD encoded audio. If the device hasn't the ability to read the Atmos metadata or portray an Atmos soundtrack then the AV receiver would revert to using the DD+ or TrueHD element of the package. THis would result in the exact same quality and definition had you been portraying Atmos. Atmos metadata simply tells the AV receiver info regarding the objects associated with the Atmos mix. The acual audio is the same audio included wit the DD+ or the TrueHD encoded audio that the metadata was packaged with.

No, you are not getting lower quality audio if you play back a soundtrack that includes Atmos metadata using an AVR that isn't Atmos enabled or if there are not the speakers required for Atmos present. It is basically the exact same audio potryed differently.

If you've no Atmos speakers within your setup then the AV receiver or soundbar shouldn't even be acknowledging the presence of Atmos or Atmos metadata, not without utising Dolby Virtual Height processin. Does your AVR or sounndbar include Dolby Virtual Height processing?
 

Steve84

Novice Member
I have the denon avr x2500 h amp with kef egg speakers. I just wondered coz I was watching IT through apple tv and it displayed as Dolby atmos. Even though I only have 5.1 for speaker set up. Just wondered if I was losing audio quality this way. As note this happens for any film watched which has Dolby atmos And especially Disney+
 

Steve84

Novice Member
I have the denon avr x2500 h amp with kef egg speakers. I just wondered coz I was watching IT through apple tv and it displayed as Dolby atmos. Even though I only have 5.1 for speaker set up. Just wondered if I was losing audio quality this way. As note this happens for any film watched which has Dolby atmos And especially Disney+
On virtual height front. I don't know. I know its set up I had to use a microphone to.measure sound distance
 

dante01

Distinguished Member
The X2500 has no implimentation of Dolby Virtual Height processing so if you've only a 5.1 setup devoid of Atmos speakers then you'd not ordinarilly get Atmos. THe AVR wouldn't even acknowledge the presence of Atmos metadata without said height, ceiling or upward firing speakers.

I'd double check your speaker configurations and ensure that you've not set the options speaker assignments for those additional speakers incorrectly?


You'd not be getting any deteriation in quality whether playing Atmos or not, but you are not hearing the audio as intended if playing Atmos sans the additional speakers. There may be holes in the soundtrack being portrayed in the room you are in?
 

Steve84

Novice Member
IMG_20211016_184040.jpg

Just wanted to show it showing as atmos watching IT. So what should in look for
 

dante01

Distinguished Member
AS said, it shouldn't even be acknowledging the presence of Atmos metadata without the additional speakers being present in your setup.

Your model predates those that include Dolby Virtual Height processing. THis should not be confused with DTS's Virtual:X Virtual height processing which isn't applicable to Dolby formatted Atmos soundtracks.
 

Dolus

Active Member
In 2018 I bought a Denon 6400 AVR to use with my then current 7.1 speaker layout and if I played an Atmos film, Atmos would be displayed on the receiver.

Just to check I reconfigured my system to 7.1 and yep Atmos is displayed on the front panel Configured as stereo or 5.1 I get Dolby TrueHD+Dolby Surround displayed.
 

dante01

Distinguished Member
In 2018 I bought a Denon 6400 AVR to use with my then current 7.1 speaker layout and if I played an Atmos film, Atmos would be displayed on the receiver.

Just to check I reconfigured my system to 7.1 and yep Atmos is displayed on the front panel Configured as stereo or 5.1 I get Dolby TrueHD+Dolby Surround displayed.


The AV receiver shouldn't be doing that and I can only suggest that there's an inherant fault ion DEnon AV receivers that causes such behaviour?


The OP is also getting Atmos as sourced via an Apple TV. THis wouldn't be possible unless the OP had actually configured the ATV to output Atmos using Dolby MAT.
 

Dolus

Active Member
The AV receiver shouldn't be doing that and I can only suggest that there's an inherant fault ion DEnon AV receivers that causes such behaviour?
I have a theory, probably adding 2+2 and getting 5. :)

When I got the Denon I did not know if I had any Atmos films. All my films were on a Mede8er media player and were either Dolby or DTS.

I was looking at clips from various films to see how the Denon sounded compared to my previous AVR. It did not sound noticeably different until I played 'Jack Reacher:Never Go Back'.

It was an outdoor scene and the ambient background audio sounded completely different, more separation and layers. This is what me made me look at the receiver and see that it was displaying Atmos.

So my theory is that though configured as 7.1 the Denon is wrongly outputting 5.1.2 and sending Atmos to the rear surrounds. This might explain why it sounded so different.
 

dante01

Distinguished Member
If sounding different as well as showing Atmos on the display then yes, it must be actually applying the Atmos processing despite the absence of the ordinarilly required additional speakers?

The OP only has a 5.1 setup thpugh so the AV receiver cannot be confusing the back surrounds as being Atmos height speakers.

Whatever this is, it seems to be a pecularity associated with Denon and maybe Marantz AVRs?
 

dante01

Distinguished Member
What needs to be done is that someone needs to actually ask Denon about this. Is this intentional and are the Atmos enabled models portraying Atmos without actually including height sakers in a setup or is this a fault with the AV receiver's software?
 

dante01

Distinguished Member
Could the problem possibly be as simple as one pair of speakers being connected to the height channels erroneously?


If that were the case then the Audyssey calibration would have aborted and reported an error when it failed to detect the presence of any surround speakers.
 

JemCollector

Active Member
If that were the case then the Audyssey calibration would have aborted and reported an error when it failed to detect the presence of any surround speakers.
Fair enough. I just thought it was worth mentioning - sometimes the most seemingly difficult problem has the simplest of fixes.

Thanks for educating me though. I feel as thick as f### now! 😂
 

Dobbyisfree

Well-known Member
What needs to be done is that someone needs to actually ask Denon about this. Is this intentional and are the Atmos enabled models portraying Atmos without actually including height sakers in a setup or is this a fault with the AV receiver's software?

I can certainly say that this does not happen with an x4400 or a x3600.

However, I haven't got an Apple TV box, doesn't that encode the metadata differently? And, if so, maybe if this is a fault it is associated with that.

With the Denons above, only if height speakers are setup (or the virtual height switched on x3600) would it display Atmos. With either DD+ (with Atmos metadata) or "proper" Dolby Atmos on Bluray.
 

dante01

Distinguished Member
I can certainly say that this does not happen with an x4400 or a x3600.

However, I haven't got an Apple TV box, doesn't that encode the metadata differently? And, if so, maybe if this is a fault it is associated with that.

With the Denons above, only if height speakers are setup (or the virtual height switched on x3600) would it display Atmos. With either DD+ (with Atmos metadata) or "proper" Dolby Atmos on Bluray.
The ATV uses Dolby MAT to output the Atmos metadata in conjunction with multichannel PCM. The multichannel PCM is derrived from the DD+ encoded audio that was used by the streaming service to package the metadata with. The ATV decodes the DD+ element onboard the ATV. This is basically the same way that Dolby MAT would be used by the XBox or Windows PCs to enable them to output Atmos.

Dolby Atmos in Dolby MAT
The Dolby Metadata-enhanced Audio Transmission (Dolby MAT) encoder resides in a Blu-ray player to pack the variable bit-rate Dolby TrueHD bitstreams for transmission over the fixed bit-rate HDMI connections. A MAT decoder is subsequently employed in an AVR to unpack the Dolby TrueHD bitstreams. With the introduction of Dolby Atmos, we have expanded this technology to support encoding of Dolby Atmos content as lossless pulse-code modulation (PCM) audio.
A key benefit of Dolby MAT 2.0 is that Dolby Atmos object-based audio can be live encoded and transmitted from a source device with limited latency and processing complexity. Among the possible sources are broadcast set-top boxes, PCs, and game consoles. The Dolby MAT 2.0 decoder in an AVR outputs the object-based audio and its metadata for further processing. The Dolby MAT 2.0 container is scalable and leverages the full potential of the HDMI audio pipeline.


The ATV and Games consoles basically use it so that the console or device can easilly add sounds thast they create into the PCM audio.
 
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Dolus

Active Member
I posted this question on the dedicated thread on AVS for to 2017, 400 series of Denons.

I wonder if anyone can explain this. I have Denon X6400H and when I play an Atmos track with a 7.1 speaker layout the Denon displays that the source is Atmos and the output is Atmos, (see pic).

DSCF0423.JPG



Here is the reply so far that is interesting:-

I asked the same thing a while back. The answer got pretty complex. In fact we talked about it for about 20 some pages worth on the Dolby Atmos thread here on AVS.
Very simply, the 6400 will engage the Atmos decoder if you have Atmos input and at least 7 speakers configured. Dolby is not very open about how their processor functions in this (or in any) case.
But, I can tell you that when I disable Atmos the sound changes noticeably. Atmos is not absolutely tied to having height speakers (though this enables the 3D space aspect) rather it is an object based method of distributing sound among the available speakers. The concept of channels are not used the same way that they have been traditionally. So the speculation I have is that when the Atmos engine is engaged objects are trying to be represented the best that they can with your 7 speakers. Of course the ability get any elevation (and therefor 3D) information is not there.
So anyway, the Atmos indication simply means that the Atmos engine has been engaged in the receiver. It is working exactly as it was designed to.
You can try comparing the sound by enabling and disabling ATMOS in the sound options menu. I tend to like it better turned on... or maybe it is just the mental stimulation (placebo) value of seeing that glorious ATMOS word on the display...


#14.438
 

dante01

Distinguished Member
I posted this question on the dedicated thread on AVS for to 2017, 400 series of Denons.

I wonder if anyone can explain this. I have Denon X6400H and when I play an Atmos track with a 7.1 speaker layout the Denon displays that the source is Atmos and the output is Atmos, (see pic).

View attachment 1588264



Here is the reply so far that is interesting:-

I asked the same thing a while back. The answer got pretty complex. In fact we talked about it for about 20 some pages worth on the Dolby Atmos thread here on AVS.
Very simply, the 6400 will engage the Atmos decoder if you have Atmos input and at least 7 speakers configured. Dolby is not very open about how their processor functions in this (or in any) case.
But, I can tell you that when I disable Atmos the sound changes noticeably. Atmos is not absolutely tied to having height speakers (though this enables the 3D space aspect) rather it is an object based method of distributing sound among the available speakers. The concept of channels are not used the same way that they have been traditionally. So the speculation I have is that when the Atmos engine is engaged objects are trying to be represented the best that they can with your 7 speakers. Of course the ability get any elevation (and therefor 3D) information is not there.
So anyway, the Atmos indication simply means that the Atmos engine has been engaged in the receiver. It is working exactly as it was designed to.
You can try comparing the sound by enabling and disabling ATMOS in the sound options menu. I tend to like it better turned on... or maybe it is just the mental stimulation (placebo) value of seeing that glorious ATMOS word on the display...


#14.438


I concur with this and it isn't just Denon or Marantx AV receivers that it effects. Here's what I get if I reconfigure my 7 channel Yamaha RX-A1080 from a 5.1.2 configuration to a 7.1 setup:

by default 2021-10-18 at 19.37.21.png



One would therefore have to conclude that it is normal if you've a 7.1 speaker setup devoid of height, ceiling or upward firing speakers?

The same is not however the case with a 5.1 setup devoid of said effects speakers. Not onboard a Yamaha AVR anyway:

by default 2021-10-18 at 19.42.36.png



Atmos metadata is ignored without the presence of back speakers or heights.


I should stress that the above was done using the exact same Dolby TrueHD Atmos soundtrack accessed using the AV receiver connected to a Zidoo Z1000 Pro Media player. THe title being played was the recent UHD release of Marvel's Black Widow.


No animals or children were harmed during this experiment.
 
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