Dolby Atmos® FAQ

[ssully]

I use "Direct" mode almost exclusively as that delivers the best sound to me in my room. My room is sort of "dead" sounding so not a lot of reverb to tame so I have not found Audyssey to be beneficial. Even in Direct mode, you can still do some degree of bass management by setting the crossovers for your speakers manually. In my dual subwoofer setup, I have Subwoofer Mode set to "LFE+Main", the the front speakers set to "Large" with crossover set to 40 Hz, and the rest of my speakers set to "Small" with crossover at 80 Hz. I believe this means there may be some doubling of very low frequencies between the front speakers and the subs, but after much tweaking I like how it sounds, the bass is nice and deep and tight on all kinds of recordings, and the results look reasonably good when measured with REW and a UMIK-1 mic.

Sorry if this strays off topic - not specifically Atmos-related, so mods, feel free to move this to an appropriate thread if necessary.

Audyssey isn't really for taming the sort of reverb that makes a room sound 'live' (in an extreme case, making flutter echo). It's for taming room modal peaks (and to a lesser degree, room modal troughs) , i.e. bass issues, and aims for even frequency response at the listening position, which can mean correcting a speaker's non-flat on-axis signal, as well as reflected sound (the mic can't tell them apart). If your speakers perform well on and off axis as measured by e.g. a Klippel, then 'room correction' above bass frequencies is probably not needed.

 

[Sal1950]

I'm using a AVRX3300W, all tracks are ripped from discs, and played via foobar2k/WASAPI/HDMI.

I'd simply like to make the comment and please don't take this as any rip on your Denon Ssully, it's near impossible for us the make valuable comparisons of the various ways our AV's handle 4.0 input..
Over the last decade it appears as though some manufactures have tried to improve the playback of true 4.0 sources but the reality is that it has changed with nearly every model/year. My current Denon X4700H gets mostly everything right but going back a few years to my Marantz 7703 pre/pro and the results were completely different, as they were again with the 7701 I owned before it.
I guess it took manufacturers a while to catch on to the fact that we enthusiasts still played our old valued 4.0 recordings, and in a number of different manners.

 

[ssully]

I'd simply like to make the comment and please don't take this as any rip on your Denon Ssully, it's near impossible for us the make valuable comparisons of the various ways our AV's handle 4.0 input..
Over the last decade it appears as though some manufactures have tried to improve the playback of true 4.0 sources but the reality is that it has changed with nearly every model/year. My current Denon X4700H gets mostly everything right but going back a few years to my Marantz 7703 pre/pro and the results were completely different, as they were again with the 7701 I owned before it.
I guess it took manufacturers a while to catch on to the fact that we enthusiasts still played our old valued 4.0 recordings, and in a number of different manners.

Hardly impossible. Simply report what your AVR is and what it does with a true 4.0 digital input (and additionally, how DSU upmixing works with a correctly recognized 4.0 input, e.g. , does it generate C channel output?). Valuable to me.

I'm very aware that AVRs have changed handling of 4.0 over the years, having personally experienced it; that's why I'm asking.

Do any of your AVRs upmix a true 3.0 input?

 

[Sal1950]

Hardly impossible. Simply report what your AVR is and what it does with a true 4.0 digital input

Understood, really just pointing out how confusing it can be to many.
"but, but, but, mine doesn't act that way... LOL

Do any of your AVRs upmix a true 3.0 input?

Sorry I don't currently have any 3.0 sources to test with or I'd be glad to.

 

[mandrix]

My Onkyo TX-NR656 5.1.2 AVR will play true quad through Foobar, and I can set the AVR for DSU and get sound from the heights but not the center.
Don't currently have the TX-RZ50 (so no 7.1.4) to test but suspect it's probably the same. No 3.0 and don't care about it anyway.

 

[AYanguas]

First, play a few true 4.0 (no silent channels) source, without DSU. Does your Denon show 'stereo' or 'Mch In'? (or you can press the 'info' button on the remote, and see which input channels are active).

Please let me know what 4.0 tracks you played, so I can try to replicate

The Denon shows "Mch In"
It shows only the four channels input active: FL, FR, SL, SR

I'm playing a FLAC (4 channels), from Suzanne Ciani Quadraphonic Live. using Oppo 203 via hdmi.

You can 'build' mch WAV files, with the channels you want, using Audacity or better with the MMH tool here in the forum (menu 'Remix Channel Layout'). And then convert to mch FLAC if you wish.

Last, can you tell me what model # your DenonAVR is, and/or how old it is?

It is shown in my signature: Denon AVC-X8500H (2018). AVC is the European version (without radio tuner) instead of AVR

I'm not sure what you mean here. In my experience 4.0 audio in a 5.1 container (i.e., having only silence in C and LFE tracks) will simply play silence from the C and LFE (unless bass management is on, in which case 4 channels of bass is routed to the 'subwoofer' out). It can only be 'upmixed' by DSU to added back/side speakers, e.g. to 7.0

What I *do* observe is that my current Denon sees 4.0 as 2.0**, in which case turning DSU 'on' produces 'upmixed' output from all 5 main channels, just as it would for any stereo source. Doesn't sound good, though.

None of the 3.0 tracks I own (Mercury Living Presence) will play as true 3.0. There are seen/played as 'stereo' unless I add 'silent' LFE/back channels.

I'm using a AVRX3300W, all tracks are ripped from discs, and played via foobar2k/WASAPI/HDMI.


**unless the two rear channels are formatted as 'SL and SR' rather than 'BL' and 'BL'. Then the Denon does see a 4 channel 'Mch In' signal, and DSU can be activated on top of it. Unfortunately I have so far only found a single, unofficial, quad release that uses SL/SR rather than BL/BR formatting.

What I mean is that if the 4.0 source is formatted 'into' a DTS or AC3 format (with silent channels), then the AVR will see it just as 5.1 DTS or AC3, and the DSU upmixer will work as usual for those formats.

Some AVR's or players could have restrictions to 'understand' mch if there are a weird number of channels different from 5.1. And then play it just as stereo.

My Oppo 203 does play mch 4.0 and 5.1, but cannot play 7.1. I use DUNE instead, to play mch 7.1

I think is better to 'build' mch files with a 'standard' number of channels, like 5.1. With silence in the channels with no content. Full compatibility for all systems.
Some players/AVR could not process 5.0 (a file with only five channels), for instance. 3.0 could be even more 'weird'.

In my system, and it may be the 'standard', in a 7.1 system, 4.0 or 5.1 files direct the rear channels to the Side Surrounds (not to the surround backs)

If I want to play Quad using the Surround Backs (rears instead of sides) in my 7.1 (without reconfiguring custom speakers assignment), I have to build a 7.1 file with silence in the sides and move the sides to the rears. It can be easily done with MMH, there is an option exactly for doing that.

 

[Owen Smith]

In my system, and it may be the 'standard', in a 7.1 system, 4.0 or 5.1 files direct the rear channels to the Side Surrounds (not to the surround backs)

That is, unfortunately, the standard. It's also rarely what anyone actually wants. To my mind it's a good reason for sticking with a 5.x.x system, thus avoiding the problem entirely.

 

[mandrix]

That is, unfortunately, the standard. It's also rarely what anyone actually wants. To my mind it's a good reason for sticking with a 5.x.x system, thus avoiding the problem entirely.

Well I agree with your first two sentences. lol.

 

[Sal1950]

That is, unfortunately, the standard. It's also rarely what anyone actually wants.

I only have a 5. system so no experience, but isn't there a way to configure the system the way you want?

 

[sjcorne]

That is, unfortunately, the standard. It's also rarely what anyone actually wants. To my mind it's a good reason for sticking with a 5.x.x system, thus avoiding the problem entirely.

I used to think that, but having different isolated elements in the side surrounds versus the rears is actually a really cool effect.

 

[Sal1950]

I used to think that, but having different isolated elements in the side surrounds versus the rears is actually a really cool effect.

In the past I didn't see it as a big deal, but most recently, 7. recordings that are really using those channels has become much more the norn. Wish I had the room.

 

[par4ken]

I used to think that, but having different isolated elements in the side surrounds versus the rears is actually a really cool effect.

I get adding isolated elements in the side surrounds could be rather cool. I question the need for height speakers though, other than for movie sound effects and I don't really want to be that immersed in a movie!

 

[himey]

I question the need for height speakers

Questioning from experience, or just pondering the possibility?

 

[mandrix]

I find a 7.1.4 Atmos system just A-OK for me. With the proper Atmos mixing, the music comes to life. With a good mix, there is enough coming from all speakers to create a truly "immersive" experience.
I would even go 7.1.6 if I could, but 7.1.4 is pretty cool to me.
Would not tell anyone they would like an immersive setup, but to me it's a logical extension of the road we as mch listeners have been on for near a lifetime of music listening. Quad, 5.0, 5.1, 6.1, 7.1 etc.

 

[Sal1950]

I question the need for height speakers though, other than for movie sound effects and I don't really want to be that immersed in a movie!

IMO, your missing out on the best music and movie listening experience yet devised, so I have no understanding of why you "don't really want to be that immersed in a movie!" ? Your deduction of having no interest leaves me completely confused. Have you actually heard some of the best sources played on a high quality system?

 

[AYanguas]

That is, unfortunately, the standard. It's also rarely what anyone actually wants. To my mind it's a good reason for sticking with a 5.x.x system, thus avoiding the problem entirely.

I think this is the right way, because:

- At the begining there was only 5.1 --> Quad rears go to channels 5,6
- Later, two additional surround backs were added to get 7.1 --> Quad rears still go to channels 5,6. The same. Not change to 7,8
- I think normal Dolby Atmos channel layout is first sides (5,6) and then rears (7,8)
- If they code Quad into a 6 channel file (5.1), obviously thay have to go to channels 5,6. This is the normal way to deliver Quad into DTS, for example.
- Nobody codes Quad into 8 channels (7.1), except some of us when manipulating the layout.

There are good Atmos mixes with different discrete content in sides and rears. Sides can give binaural effects, but rears content give additional and different rear effect --> Good reason for upgrading to 7.x.x

If labels would release a Quad mix (from 70's) to be listened from rears on a 7.1, they should deliver it using Atmos, for instance. But then there will be someone who complains that it is a 'fake Atmos'
because it does not use all the available channels while It seems that no one complains about the lack of Central and LFE when a Quad is supplied in dts hd-ma.

 

[mandrix]

Unfortunately there are "immersive" mixes in quad which to me is just weird, on the streamers.
Main vocals from rears, all sorts of weird ju-ju. No thought or effort, IMO. Just because you work for a Dolby "approved" shop means nothing from what I've seen.
Crank 'em out. Good on headphones maybe, I would not know.

Good thing is BD's in Atmos are overall done well.
As far as quad rears coming not from the surround back speakers on an immersive setup, I've just adapted to it. But my side surrounds are better speakers anyway.
Nothing is going to make all of us happy, and I do wish the AVR's would do a better job with Quad in speaker placement on an immersive system, for sure. But don't think they much care.

 

[AYanguas]

As far as quad rears coming not from the surround back speakers on an immersive setup, I've just adapted to it. But my side surrounds are better speakers anyway.
Nothing is going to make all of us happy, and I do wish the AVR's would do a better job with Quad in speaker placement on an immersive system, for sure. But don't think they much care.

It is, always, a matter of resources: budget and possibility of good speaker placement.

If you want to optimize your system for 'all' formats, then you need a different 'optimum' layout for each format:

- Quad
- 5.1
- Dolby Atmos
- Auro-3D

For all this four formats I have it clear. Not yet clear for 360RA, unless it is delivered 'as Atmos', without its weird layout of Low Frontal Speakers, and that.

 

[Mr. Afternoon]

I'm honestly not sure if I can do Atmos when the room my speakers are in has a ceiling 20 feet high. Can anyone advise? I don't think I can realistically do speakers from the ceiling. Do upfiring speakers get close or should I not even bother?

 

[Sal1950]

Do upfiring speakers get close or should I not even bother?

Upfiring speakers depend on reflections from the ceiling to work and I wouldn't imagine a 20' ceiling would work at all effectively.
What about side wall mounting firing downward into the MLP.
Could that be an option for you/