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A Guide to Dolby Atmos in the Home

dante01

Distinguished Member
Anybody noticed some Atmos mixes are lower in volume and dynamics than the TrueHD core or the lossy DD 5.1 mix for some specific films?


And I mean a HUGE volume level difference, not a small one.


It is most notably more often than not Disney titles that have portrayed this issue. No one knows why exactly, but Disney are obviously doing something that everyone else isn't when either mixing or encoding the soundtracks? It is often suggested that you simply increase the master volume in order to compensate while watching Atmos encoded Disney titles.

Using Neural:X upmixing isn't a resolution because you'd no longer be getting Atmos if applying Neural:X upmixing to the underlaying TrueHD 7.1 soundtrack. The Atmos metadata would be ignored by the AV receiver in such instances.
 
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r9800pro

Active Member
It is most notably more often than not Disney titles that have portrayed this issue. No one knows why, but they are obviously doing something that everyone else isn't when either mixing or encoding the soundtracks? It is often suggested that you simply increase the volume in order to compensate while watching Atmos encoded Disney titles.

Using Neural:X upmixing isn't a resolution because you'd no longer be getting Atmos if applying Neural:X upmixing to the underlaying TrueHD 7.1 soundtrack. The Atmos metadata would be ignored by the AV receiver in such instances.
This is true. I first noticed this behaviour with Disney but Charlie's Angels is Sony's and Midway is Lionsgate's. Could it be a 3rd party mixing company that does this?

Again, Midway's Atmos mix isn't bad at all by itself unlike Disney really bad mixes but it still lacks "something". Even when I raise the volume it still lacks some punch unlike the lossy DD 5.1 EX track or the TrueHD core track which is funny.
6 dB more is like 50% increase in loudness, right? This is also what I hear with my own ears indeed.

I tested another Sony STR-DN1080 unit with the same exact issue so either it is the film itself or the AVR model.
I have a friend with a Denon AVR-X1300W and he told me he doesn't have this issue but maybe he has dynamic audio enabled.

I know that Neural: X is not a solution as I prefer the real Atmos immersive mix with no upmixing but that volume level difference and the better dynamics really annoy me.
 

r9800pro

Active Member
By the way, the last film with Atmos mix I watched was: Terminator: Dark Fate and it was reference quality. One of the best Atmos mixes ever made and it was flawless in every aspect. Maybe this means my setup isn't at fault here but who knows? Maybe some films don't play well with some AVRs if mixed in certain ways?
 

dante01

Distinguished Member
If your friend is engaging Dynamic EQ then he;d not be getting the soundtrack as it was mixed at listening levels below 0db (reference). Dynamic EQ tends to make the effects sound a little overblown and it is usually suggested it be turned off nboard Audyssey equipped AV receivers that include it.

You only get the full dynamic range as experienced by whoever mixed the soundtrack if listening at reference. This level isn't really conduxive with home theatre use though and would be louder than most households would want to be playing audio at. The soundtracks are the same mix as that which you'd experience in a movie theatre so are mixed to be portrayed at volume levels you'd not ordinarilly portray audio at in a home enviroment.

Regardless of the AV receiver, the audio shud be portrayed in the exact same way as long as the AV receiver is correctly calibrated.
 

r9800pro

Active Member
I agree with all that. This is why I never engage any kind of audio processing/enhancements/DRC or whatever.
The Sony STR-DN1080 doesn't have relative audio range so I don't really know what the reference level is. It uses Absolute range from 0 to 72 and I set it usually to 36 which is more than enough for my room. For problematic Disney mixes, I set it to 45 or 50 and they still sound compressed and lacking.

For Midway, level is very good at 45 but still lacks a little punch. 50 is a bit too loud. TrueHD core and Lossy DD 5.1 EX sound amazing at the usual level of 36.

What really borhers me about Midway Atmos mix is that I saw youtube reviews for it that gave it 10/10 but if this issue I am experiencing is not a fault in my setup then it is a flawed mix in my book.
 

r9800pro

Active Member
Okay, here is a new discovery;

What I first tried and posted about was the Blu-ray, not the 4K version of Midway and I just tried the 4K and lo and behold... both the Atmos mix and the TrueHD core are the exact same sound level lol

In the scene from 10:20 to 10:45 minutes, Atmos max was 92 dB, TrueHD core was also 92 dB and DD 5.1 EX was 96 dB. DD 5.1 is still much louder but Atmos is better anyway.

It is so funny for a studio to mix TrueHD core for the Blu-ray much higher than Atmos but the same level for the 4K.
 

dante01

Distinguished Member
SD formats are subject to compression and tend to have less dynamic range because of this. THe compressed dynamic range results in quieter aspects of the soundtrack being forced up and the louder aspects being forced down. THis gives the impression that the audio is louder than you'd experience if listening to a less compressed example with wider dynamic range. Many Dolby encoded soundtracks (especially those intended for TV broadcasts) are also subject to normalisation which would also effect the volume at which a device portrays it. THere may be metadata within the audio that effects the dialogue levels for example.
 
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r9800pro

Active Member
Indeed this must be the case and it makes perfect sense at least for the lossy DD 5.1 mixes.
It is still a bit strange for TrueHD core to be different between Blu-ray and 4K UHD.
 

dante01

Distinguished Member
The soundtrack you get with both the Midway HD Blu-ray and the UHD disc is the exact same TrueHD/Atmos soundtrack. The Atmos soundtrack isn't exclusive to the UHD release.
 

r9800pro

Active Member
The soundtrack you get with both the Midway HD Blu-ray and the UHD disc is the exact same TrueHD/Atmos soundtrack. The Atmos soundtrack isn't exclusive to the UHD release.
I know that but as I said earlier, the TrueHD core on the Blu-ray is much louder than the Atmos while the 4K UHD disc has the exact level for both tracks. That seems really strange to me.
 

dante01

Distinguished Member
It is the exact same TrueHD soundtrack with the same Atmos metadata packaged with it. The studios and or distributors don't mix different soundtracks and the same audio formats are used for both HD and UHD discs. There are not 2 soubdtracks and the Atmos soundtrack is simply a result of the instructions the metadata conveys to the AV receiver telling that receiver what to do with the audio data encoded within the TrueHD encoded audio. THe receiver would react in the exact same way irrespective of whether bitstreaming the TRueHD plus Atmos metdata audio sourced via a HD Blu-ray disc or when accessing that same audio via a UHD disc. THere's just one TrueHD soundtrack with the metadata packaged with it and not a seperate TRyeHD and Atmos soundtrack.

The TrueHD/Atmos packaged audio will be the same via both discs and the Atmos metadata is iclusive to the TrueHD packaged audio.


Dolby Atmos in Dolby TrueHD
Dolby expanded the Dolby TrueHD format employed in Blu-ray Disc media to allow the format to support Dolby Atmos content. Prior to Dolby Atmos, Dolby TrueHD provided lossless support exclusively for channel-based audio, such as 5.1 and 7.1. We have added a fourth substream to Dolby TrueHD to support Dolby Atmos playback. This substream represents a losslessly encoded, fully object-based mix.

Dolby Atmos signals encoded in Dolby TrueHD are transmitted from a Blu-ray player to your sound bar with Dolby Atmos through an HDMI connection. The sound bar receives the Dolby TrueHD soundtrack and its associated object-based audio and positional metadata, and then decodes, processes, and renders the sound to the specific speaker configuration in the device.
Dolby Atmos audio can be encoded with Dolby TrueHD at multiple sampling rates (including 48 kHz and 96 kHz) and bit depths (16-bit and 24-bit). Dolby Atmos enabled sound bar products will also support legacy Dolby TrueHD bitstreams at multiple sampling rates (including 48, 96, and 192 kHz) and bit depths (16-, 20-, and 24-bit) to provide full backward compatibility with legacy Blu-ray Disc media and Dolby TrueHD music files.

Dolby Atmos in Dolby Digital Plus
Dolby Digital Plus has been updated to include a new decoder capable of processing content encoded for Dolby Atmos. This module employs new bitstream metadata to extract Dolby Atmos object-based audio and then outputs this information for further processing by the object audio renderer, which adapts and scales the Dolby Atmos mix for the onboard speaker system in the sound bar. The sampling rate for Dolby Atmos content is 48 kHz, the same sample rate as for Dolby Digital Plus content.
10
Dolby Digital Plus is employed for over-the-air (OTA) and cable broadcast delivery and is the preferred audio codec for multichannel OTT or streaming media content.

Full compatibility
Both audio decoders are designed to be fully backward compatible with legacy channel-based Dolby Digital Plus and Dolby TrueHD soundtracks.

Dolby Atmos in Dolby MAT
A 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. A Dolby MAT decoder is concurrently employed in the Dolby TrueHD decoder in the sound bar to unpack the Dolby TrueHD bitstreams. With the introduction of Dolby Atmos, we have expanded the Dolby MAT technology to support encoding and decoding of Dolby Atmos metadata incorporated in 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 likely sources are broadcast set-top boxes and game consoles. The Dolby MAT 2.0 decoder in the Dolby Atmos enabled sound bar outputs the object-based audio and its metadata for further processing inside the device. The Dolby MAT 2.0 container is scalable and leverages the full potential of the HDMI audio pipeline.
 
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Donovan84

Standard Member
Any geometry whiz’s out there? I’m guessing there is a simple formula for this, but I don’t know what it is. According to Dolby, when using 4 Atmos speakers, the front speakers are 45 degrees from the listening position and the rears 135 degrees. How many feet (sorry, I’m over here in the U.S.) in front and behind the listening position for the speakers if the ceiling is 9 or 10 feet high? Thanks!
 

dante01

Distinguished Member
Any geometry whiz’s out there? I’m guessing there is a simple formula for this, but I don’t know what it is. According to Dolby, when using 4 Atmos speakers, the front speakers are 45 degrees from the listening position and the rears 135 degrees. How many feet (sorry, I’m over here in the U.S.) in front and behind the listening position for the speakers if the ceiling is 9 or 10 feet high? Thanks!
 

mrroboto

Standard Member
Hi All!

I own a 5.2.2 setup wit height speakers positioned on the front wall up to the ceiling. I’m just curios to know what are the differences in sound between the avr options “ceiling” and “height speakers”. I mean the sonic differences.
 

dante01

Distinguished Member
Hi All!

I own a 5.2.2 setup wit height speakers positioned on the front wall up to the ceiling. I’m just curios to know what are the differences in sound between the avr options “ceiling” and “height speakers”. I mean the sonic differences.

It is unclear as to what if anything is being done differently to the audio in association with the height and ceiling speaker options. The differences are more a matter of the manner in which the speakers are locaed and positioned. Ceiling speakers will better portray overhead effects and will better convey what the person who mixed the soundtrack heard while they were mixing it. Height speakers are a bit of a compromise, but will give you more immersion than you'd have had without them. The upward firing option on the otherhand may actually bypass the AV receiver's room EQ correction due to the way in which such processing effects the HRTF crossover filters employed with Dolby endorsed Atmos enabled speakers. This is unfortunate given that many regard the inclusion of HRTF as being unnecessary and in many regards detrimental:

 

mrroboto

Standard Member
It is unclear as to what if anything is being done differently to the audio in association with the height and ceiling speaker options. The differences are more a matter of the manner in which the speakers are locaed and positioned. Ceiling speakers will better portray overhead effects and will better convey what the person who mixed the soundtrack heard while they were mixing it. Height speakers are a bit of a compromise, but will give you more immersion than you'd have had without them. The upward firing option on the otherhand may actually bypass the AV receiver's room EQ correction due to the way in which such processing effects the HRTF crossover filters employed with Dolby endorsed Atmos enabled speakers. This is unfortunate given that many regard the inclusion of HRTF as being unnecessary and in many regards detrimental:

Thank you for the answer. I know the differences between different kind of Atmos setup and speakers but I want to know about the avr processing depending of those choices. I can hear a very different sound between ceiling and height options and actually are both good enough to my ears. Ceiling option is more detailed in higher response and height option is more wide but more enfasis on the mid frequencies. I think height better blend with the mains. Still undecided, need more infos.
 

dante01

Distinguished Member
I too would say I can hear a difference, but from the research I've done, it would appear there is no diference when it comes to the processing?

I definately haven't found any of the manufacturers stating that they apply any different processing in relation to either.
 

mrroboto

Standard Member
I too would say I can hear a difference, but from the research I've done, it would appear there is no diference when it comes to the processing?

I definately haven't found any of the manufacturers stating that they apply any different processing in relation to either.
Dante I know you have a very similar set up to mine with height speakers on the very top of the wall and you own a Yamaha avr. Are yours speaker set up as height front?
 

dante01

Distinguished Member
Dante I know you have a very similar set up to mine with height speakers on the very top of the wall and you own a Yamaha avr. Are yours speaker set up as height front?
Yes.

I've not heard anything that suggests thst setting them as being ceiling speakers would make that setting preferable. I would however suggest that actual speakers physivally located overhead would be preferable to height speakers.
 

Nobbler

Distinguished Member

Food for thought?
I personally find Dolby Atmos underwhelming apart from a handful of films...most of which have been mentioned here.

The video involves a guy who gets students to listen to films with only the height speakers on. In Aquaman they found precisely 2 and a half minutes of information sent to those channels...
 

gibbsy

Moderator
In Aquaman they found precisely 2 and a half minutes of information sent to those channels...
The clue is in the title.....Aquaman. :)

It's still worth the investment for bringing an extra dimension to those standard 5.1 and 7.1 titles when employing the upmixing modes.
 

Nobbler

Distinguished Member
The clue is in the title.....Aquaman. :)

It's still worth the investment for bringing an extra dimension to those standard 5.1 and 7.1 titles when employing the upmixing modes.
And that’s what they say if you haven’t seen it. Upmixing is 9/10 better than the Atmos mix if height effects are your thing..:
 

FinnedSgang

Active Member
Do you have a list of the essential atmos movies?
I found astonishing "A quiet place"
Didn't like so much the Atmos track of Godzilla king of the monster and Aquaman that were 2 of the most suggested titles to try atmos with
 
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FinnedSgang

Active Member
The clue is in the title.....Aquaman. :)

It's still worth the investment for bringing an extra dimension to those standard 5.1 and 7.1 titles when employing the upmixing modes.
noob question, what upmixing means and how to activate on a denon for example?
 

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