Solving playback issues

[WaltSm53]

Hello. First, my setup. My setup.

Samsung UHD TV model UN55JS700

Klipsch 600 Cinema connected to the TV via HDMI ARC

Roku Ultra 4670RW Build 4208 connected via HDMI to TV, Sound set to Auto for best available sound, Dolby Digital or DTS.

TIVO OTA device for TV antenna programs connected to TV via HDMI, Sound set to Dolby Digital

I have the Samsung TV sound settings set at "HDMI Audio Format = Bitstream" and "Audio Format = Dolby Digital". I tried PCM but the only option not grayed out is DTS, which the Cinema 600 does not support.

When I watch programming from the antenna and TIVO box, Dolby Digital lights up on the Cinema 600. All channels, either HD or SD.

But when I switch to Roku and watch Amazon Prime video, I have no Dolby Digital. IN FACT, when I check the TV sound settings while watching Prime, the "Audio Format" for the TV has changed from Dolby Digital to PCM. And Dolby Digital is grayed out in the options. But if I switch back to TIVO and antenna TV, the setting is back to Dolby Digital.

I'm stumped why this is happening and would appreciate any feedback. I'm trying to have Prime shows broadcast Dolby Digital through the Cinema 600. Is there something more I need to do with the Roku?

Thank you

Walt

[remaker]

I assume you already read https://support.roku.com/article/208754498.

I would swap the HDMI cable from the TV to the Roku for a unit with working Dolby Digital to start in order to rule out the HDMI cable.

Could be a software bug, otherwise. Not sure about the HDMI negotiation protocols. 

[WaltSm53]

Thanks for replying. I did review the proper connectivity directions for hooking up the Roku to a soundbar and TV. I swapped out the HDMI cable connected to the Roku and TV but I see the same results.

I also connected a different soundbar to the TV, but one which supports Dolby Digital, Digital + and DIX. I see the same result, no Dolby Digital pass thru, because like the other soundbar, Dolby Digital becomes grayed out in the TV Sound settings when I stream through Roku. The difference is DIX. Because this soundbar supports DIX, DIX is an available TV sound setting when streaming through Roku. So the issue is still why Dolby Digital is not passed through Roku successfully when streaming channels.

One thing I will probably do is return the new soundbar and purchase one that at least supports DIX plus Dolby Digital. That way I'll have DIX as an option for sound settings.

As for why Dolby Digital is not being passed through when streaming via Roku, that is still a mystery to me.

Thx

[WaltSm53]

Sorry...meant to say DTS not DIX.

[remaker]

Sorry, I don't know. I would guess that the TV or the Roku has a protocol bug. There may be some magic combination of settings that makes it work, but without an HDMI protocol analyzer, you're just guessing. And those will set you back $1,000-$15,000. Unless you have a friend that has one.

Cheaper to buy a new TV.