My Roon-Ready Pioneer LX805 AVR already supports Atmos, DSD up to 11.2MHz, PCM and even Multichannel-PCM.
But the problem is, RAAT protocol doesn’t seem to support multichannel so none of it can be taken advantage of.
Roon Team really needs to update RAAT or whatever they need to so perfectly capable AVR can stream MCH music like Atmos directly. 
[Moderated]
RAAT supports as many channels as your audio device tells Roon it has. If multichannel is not working its because your AVR is telling Roon it only supports 2 channels.
You can usually “fix” this by plugging a PC into the AVR using HDMI and installing Roon Bridge on that PC. I use a mini-pc running Linux for this purpose. I have also just carried a laptop over to my AVR and plugged it in as well.
RAAT is perfectly capable of handling multichannel up to 7.1, but there are very few roon ready devices out there accepting such a stream (and none of them being a consumer grade AVR as far as I know). Seems to be an issue of the streaming module within these devices.
Atmos is not supported yet, I guess due to licensing and rights management issues. Only very few formats and protocols can handle an Atmos stream to the liking of Dolby. Except from their own and closed streaming service formats I know only M4A and MKV files keeping the embedded Atmos stream untouched which would not be working with roon´s internal handling of streams.
If you have a Nucleus or run roon on a NAS with capable HDMI-out, it is even easier as these HDMI-out appears in the list of activatable roon renderers.
my LX805 AVR already natively supports M4A playback using its built-in Music Server and even USB function, so I don’t think the “streaming module within these devices” is the issue.
This sounds more like it.
Since RAAT is capable of MCH already, according to you, I think it’s Roon’s problem of not supporting a MCH format like M4A.
Roon supporting M4A should instantly make my M4A-capable and Roon-Ready AVR play Atmos direclty from Roon.
Roon Team, could you make this happen, yes?
I really dislike adding another device is an understatement.
It does not make sense to have to add Nucleus, NUC, PC or Mac mini in between, when my AVR is already natively Roon-Ready itself.
That’s why I really want to understand why MCH or Atmos playback directly via Roon is not possible.
Don’t get me wrong, I have tried. But the PC sleep/wake issues, HDMI-negotiation issues, Roon PC/Mac competing for another HDMI slot, Roon Bridge app freezing etc are so frustrating that I never want to add another device in between again.
No. RAAT does not send any M4A, or any other file format.
Roon does not have any Atmos decoding and does not send any M4As anywhere.
If the Pioneer does not play multichannel files, properly supported by Roon, then it is a question for Pioneer. But generrally only few, if any, AVRs support multichannel playback from Roon.
As others have said. When your “roon ready” AVR responds to Roon as a 2 channel device then that’s a feature request to the AVR manufacturer not Roon.
ATMOS is an interesting Roon feature request as ATMOS encoding is the PCM channels plus meta data. I don’t think RAAT has any way to pass the meta data. That makes ATMOS not only a licensing nightmare but a new network protocol to move it around.
But, I understand the frustration. No one has solved this yet.
My question still stands, why not?
Roon doesn’t need to decode Atmos right? Even basic AVR is capable of decoding, no?
The problem lies with Roon not sending M4A right? What is preventing Roon from making this happen, aside from licensing issue? Is there a technical limitation?
Well… if Roon sends M4A then there is nothing to request from my AVR because it already has built-in M4A playback function via streaming.
The issue is mainly due to Roon not supporing or sending M4A file, no?
I don’t have the technical background to know what goes on with RAAT and Atmos, but I do know this situation cannot keep going on, due to the prevalence of Atmos already.
Thanks
Roon Team, hope you are listening/reading, and yes, acknowledging this issue would be nice. Unless Dolby is forcing you to keep quiet during licensing negotiations 
Stop with the M4A talk. You answered your own question right there. M4A is not an audio codec. It is a file format, a container. Well, Roon does not “send” files. Roon decodes and processes files, then delivers audio streams.
AJ
“Stop with the M4A talk”
Excuse me, ad hominem attack like this is against TOS of this forum and not civil.
Are you trying to say that unless Roon decodes Atmos and “delivers” Multichannel PCM to my AVR, then I will never get Atmos from Roon? Sorry, your short messages are super unclear to me.
A direction is not an ad hominem. You may not like the direction, but it is not an attack.
AJ
If Roon were to decode Dolby Atmos to PCM, then it no longer would be Dolby Atmos. It would be just PCM, and an AVR display likely would reflect that.
AJ
Whether I like or dislike the direction of your post does not make it civil for you to say "Stop with the M4A talk” as if it’s acceptable behavior to attack/direct others like this on this forum, especially when I was genuinely asking if it’s due to technical limitation.
There are many ways to improve communication such as apology but using language to censor others is not one of them.
Yes I understand this. But my AVR supports Multichannel PCM too so why does it not support MCH playback in the Roon → AVR chain?
Is it as some posters have claimed that, without concrete evidence yet, that the streaming module in the AVR doesn’t support it?
Roon Team, could you clarify?
That is not for Roon to clarify. As others already have told you, talk to Pioneer.
Roon does not dictate what RAAT capabilities each manufacturer implements. For example, some choose to support DSD via RAAT, while others do not. The same holds for multichannel.
AJ
Thanks for your additional comments. Yes this explains why Multichannel PCM does not work on my AVR, even though it’s Roon-Ready.
I am sorry, I don’t understand, what’s there to ask Pioneer? I didn’t say I am not going to ask Pioneer, but even if Pioneer implements multichannel PCM tomorrow, but Roon still doesn’t support Atmos decoding/processing/delivery, so what’s the point?
Roon Team, please clarify, if possible and if you are available.
Not quite. If an M4A with embedded Atmos should be processed by roon, or RAAT in particular, it would mean roon internally had to decrypt everything to a bitstream level. This is one thing that Dolby most certainly will not allow as Atmos in all forms is a pretty proprietary format and on top contains Dolby-exclusive data like additional lossy tracks and their vectorized information how to extract them from the 7.1 base layer. It is not just metadata.
Roon is not made for passing over an enclosed, proprietary file or stream format to a roon ready device unchanged. Even if this would be possible, for example with Dolby Digital Plus like in Tidal or Amazon HD, and Dolby would agree, many roon features like leveling, DSP, crosscoding and alike would not be applicable to these files.
Because the streaming engine in your AVR is most probably 2-channel-only or at least cannot process multichannel via RAAT. Can it play multichannel FLAC or WAV via Upnp?
The question is if there is any AVR or AVP out there supporting Atmos via file or ´open´ network stream protocol. I am not aware of a single one. Atmos so far is limited to options like HDMI or alike which hand over the Atmos stream untouched and in an enclosed way to the AVR/AVP which Dolby is accepting. I am not even sure it is integrated in Tidal Connect.
Because RAAT is designed to send raw bitstream (of either PCM or DSD, possibly multichannel). It does not send any particular encoded format by design, and it’s the selling point of Roon – a Roon endpoint only needs to be Roon Ready, and it will play anything Roon supports.
It would not be Roon anymore. The point of Roon, again, is that any device connectable to Roon can play anything you send to it from Roon. It does not need to know anything about any new formats, apart from knowing how to play a PCM or DSD bitstream. All processing, by definition of Roon, is done in the Roon core. If there were some Atmos (or whatever) files that could only be played on some endpoionts, it would not be Roon anymore.
Roon would need to incorporate an Atmos decoder that converts Atmos data into a discrete multichannel signal, which can be sent through RAAT just fine already. And then you’d need a device that actually supports it (most Roon Ready AVRs don’t).
Is it technically doable? Probably, although I don’t know what processing power requirements are for Atmos decoding.
Is it practically doable? Maybe, but a) Harman needs to want it, b) Dolby needs to want it, and c) there needs to be a decoder that can run on all OSs that Roon supports.
It would be neat to have, but there are a lot of i’s to be dotted, and most do not even depend on Roon itself.
That’s purely a question to Pioneer.
It is exactly that, and there’s tons of evidence. Same reason why HEOS- or Bluesound-based AVRs also do not do multichannel with Roon.