Playback Issues - Audio/Video & Power

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sonus
Level 7

Broken Roku Ultra? Why does everything downmix to PCM stereo??

I have a 2 week old  Roku Ultra 4660X (2018) model and I can't for the life of me get it to provide 5.1  audio.  Should I return it? Can I fix it?

I have an Amazon Fire Stick 4k that outputs everything over Dolby Digital, wheras my Ultra hooked up to the same TV and audio receiver only does Stereo-PCM.

My hookup is Roku Ultra>>HDMI>>Sharp Aquos LC--60LE660U/LC>>Optical Audio>>Sony DPRF6500

TV supports surround sound audio, Dolby Digital, DTS
Sony headphones support 7.1 audio and Dolby Digital, DTS, Dolby Pro Logic IIx
Tested app sources include Netflx,Hulu, HBO, Google Play
Roku Ultra is running 8.0.1 build 4090-46

My TV is set to output bit stream over the optical audio, and as per earlier my Amazon stick works perfectly over DTS, wherase my Roku Ultra only ever sends PCM both to my TV over HDMI and to my Sony via the TV's passthrough.  I have the Roku set to Dolyby Digital, DTS, and night mode off.  

What gives? Neither the TV nor the headphones register the Roku as a Dolby Digital, DTS source, yet both register the Amazon as multichannel Dolby Digital, DTS so I know at least the TV and the headphones are properly setup.
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27 Replies
Heyitsrick
Level 11

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

Easiest first step would be to swap HDMI ports as a test. Put the Roku in the Amazon's HDMI port on the receiver and vice versa. Set the Roku for Auto in the Audio section and reboot it.
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chuchanpr
Level 7

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

You will not get 5.1 audio on Netflix. Netflix encodes their audio in Dolby Digital Plus (and stereo).
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Heyitsrick
Level 11

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

"chuchanpr" wrote:
You will not get 5.1 audio on Netflix. Netflix encodes their audio in Dolby Digital Plus (and stereo).

Actually, this is the reason for your issues. The Amazon Firestick 4K will down convert Dolby Digital Plus and output standard Dolby Digital if you have it set for that. The Roku Ultra (latest version) will not do that.  So, you're only going to get 2-channel stereo over optical.  
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sonus
Level 7

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

"Heyitsrick" wrote:
"chuchanpr" wrote:
You will not get 5.1 audio on Netflix. Netflix encodes their audio in Dolby Digital Plus (and stereo).

Actually, this is the reason for your issues. The Amazon Firestick 4K will down convert Dolby Digital Plus and output standard Dolby Digital if you have it set for that. The Roku Ultra (latest version) will not do that.  So, you're only going to get 2-channel stereo over optical.  


Every app I have tried has this issue, not just Netflix though. Does anybody have ANY cases where Dolby Digital works with the Ultra?
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dfgsrzwer
Level 8

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

There isn't an app that I'm aware of on the Roku that currently uses DD rather than DD+. The last holdout was HBO, and they switched to DD+ last month.

If your receiver supports it, PCM can use Prologic II, which does a good job of converting 2 channel to 5 channel. By the way, you "tested" using Hulu. Hulu is always in PCM...if your receiver ever said otherwise it was because the device sending the info was not sending correct info (probably because it was not autoconverting; eg Xbox does this because it does not autoconvert like Roku does so Hulu will show Dolby Digital if I set the xbox to that). If you listen to the actual output only 2 speakers will have sound even though your receiver says "5.1". Setting something to DD won't change the actual output anymore than setting your resolution to 1080p changes an SD video to HD. To get actual 5.1 you need Prologic II.
Charter Spectrum 60; d-link dual band router
Roku 4210, 3710; Xbox One, 360; Samsung BD player
Samsung tablet; Windows Vista laptop; LG phone
Toshiba DVD-R; Sony AVR; Panasonic AR
1080p and 720p TVs
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Blue_avatar
Level 7

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

Hi all, I’ve got a similar experience that seemed to _just_ happen to my Roku Ultra (2016).   Been enjoying 5.1 sound since I got it, but suddenly I noticed it’s outputting only stereo.   This was experienced on a Netflix movie, so naturally I suspected maybe Netflix did something or I needed to check a setting.   When that didn’t work, I checked Plex ... also stereo.  Now recently Plex made a server update so I’m thinking a similar situation happened there.   Thankfully I have an Xbox One that can also run Netflix and Plex ... and it played the same movies in 5.1.   So this takes me back to the Roku, and likely something changed there.   I checked system update and saw an update was just made on 6/28.   Anyone know what this update contained?   I wrote to Roku but have received no reply.

Thanks for any suggestions!
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azurenepsa
Level 8

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

The 8.1 update killed the 2016 Ultra's ability to output DD 5.1 over HDMI.  Here's a link to the thread where Roku acknowledges the bug:
https://forums.roku.com/viewtopic.php?f=28&t=116363

In my setup, I'm still able to transcode to DD 5.1 over optical, but I have no such luck over HDMI.
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Blue_avatar
Level 7

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

Thanks!  This explains it, as I am using hdmi.   
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MightyHandy
Level 7

Re: Broken Roku Ultra? Why does everything downmix to PCM stereo??

Yeah, we are all checking the forums and refreshing our ‘check for update’ every day right now. Ultra transcoding died with 8.1. Worked great before it... which is probably why they advertised it on all of the Ultra marketing materials. Right now... anything Dolby is gonna be stereo (your receiver is probably converting it to PCM). DTS still works though. Dolby is toast.
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