I have 3 Rokus, 3 different models. The only change I am making is to swap out the Rokus, otherwise ALL is the same including the source streams.
Source is 5.1 surround sound, output is capable of handling surround sound and is connected via optical cable from the TV. Roku connected to TV via HDMI.
1) Roku Express 3900R - No multi channel sound detected by receiver. Audio in Roku settings is set to Dolby.
2) Roku Ultra - No multi channel sound detected by receiver. Audio in Roku settings is set to Dolby.
3) Roku 2 - 4210R - This is the only Roku I can get to emit 5.1 surround sound to the receiver. Unfortunately this model doesn't have private listening, so I can't keep it in the location I need the 5.1 surround sound.
So the setups is ROKU<HDMI>TV<OPTICAL>RECEIVER -> Speakers
DD+ does not transmit over Optical to your receiver, that is most likely the reason you do not have 5.1 (depending on source content) at the receiver. Now why the Roku2 does? I want to say I read somewhere long ago that the Roku2 converted DD+ to DD which would then pass along your chain. I could be wrong about this though.
@ziloni You're a hero. This was driving me nuts and I stumbled upon this thread. Setup a new Samsung soundbar today with HDMI ARC connection to my Samsung TV and the Roku (Ultra 4660x) was refusing to send the soundbar a 5.1 stream. The built-in native Samsung apps were fine. This "feature" needs to be highlighted better in Roku's options on what it does and not buried in some silly secret menu.
Thanks for this post. I was about to start a whole new thread because I couldn't get DD sound through my streaming stick 3810R via ARC, or directly plugged into my AVR. But then I went and checked this and while it wasn't set to night mode, it was set to low volume leveling. Turned that off, and now I have DD+ while directly plugged into AVR. Going to try using it with ARC later. Hopefully it works because my wife generally prefers not to have to mess with the sound system at all and just watch directly through the tv, whereas I like to make the walls shake so to speak