Originally Posted by asabrag
If I were you, I would exchange it for a Denon. I really hate Denon sound but for the first time in a lot of years being Onkyo blood fan and love the distinctive Onkyo sound, If I had the chance (return period expired 3-Oct), I would exchange it.
I received answer from Japan:
"Dolby has updated DolbyAtmos (1.6) on the latest version of TX-RZ840. It supports DolbyAtmos signal.
If Old version of Dolby Atmos signal is sent to the 840, it will be misrecognized as [MultichPCM] due to limitations of the old Dolby Atmos signal. Sorry for the inconvenience, but when playing the corresponding game sound, press the “i” button to check the input audio format. If:
① Display Input sound is [Multich PCM 5.1ch], [Multich PCM 7.1ch], etc. ⇒Sorry, there are limitations on the playback device side or compatibility with this unit. Input is in multi-channel PCM format due to problems.
In this case, unfortunately, it will be difficult to resolve, so thank you for your understanding.
② Display is [Multich PCM 5.1.2ch], [Multich PCM 7.1.2ch], [Multich PCM 5.1.4ch], etc. ⇒Originally, there is no 5.1.2 / 7.1.2 / 7.1.4 ch format for multi-channel PCM. Therefore, this case corresponds to the above-mentioned misrecognition specification. Although it is mistakenly recognized If you select the [Multich] listening mode, the DolbyAtmos audio is played as it is. It will be the same as if displayed as Dolby Atmos, so please enjoy it as it is. Thank you for your patience."
I just answered no amount of channels is displayed in the Input Signal.
Did you get further answer from Onkyo Support? If you did/once you do, would you mind sharing it please?
I have exactly the same issue with Xbox and tx-rz740 receiver. Things go exactly as you described - if I choose "Atmos" in Xbox settings, I get "Multich" as input (no channels specified) and "Multich 5.0/5.0.2/5.0.4" (whichever I specify in Onkyo settings) as output. I haven't installed ceiling speakers yet, so I can't tell whether Atmos actually works or not. Yet, if I play Dolby's demo files from my Android TV box, the receiver does show Atmos signal.
If there's anything I can do to help you get Onkyo's attention to this case, just let me know.
Other than that weird Xbox issue, I really like the receiver. The sound is really great, the UI is friendly and there are super convenient things like TuneIn with autosearch of local radio stations through internet. I live in rural area where there's no FM signal, yet I love listening to a couple of radio stations. The receiver was able to find them (and a handful of other stations).
And by the way - I re-checked my old Yamaha rx-v681, it does display "Atmos/PCM" when used with Xbox, Atmos enabled. So, looks like Onkyo indeed misrecognizes the signal. Hopefully it's just the text and it doesn't affect actual sound processing, but... if it's really Atmos, it would be much more comfortable to see clear "Atmos" indication rather than "multich". And besides, if it's just about the text, it should be easy to fix, no?