Solving playback issues

[rdesalvo]

I just bought a Roku Streaming Stick 4K (2021) connected directly to my LG OLED65E6P from 2016. My TV is connected to my receiver via optical cable. Through this cable, I am able to enjoy Dolby and DTS surround sound from the LG native apps (Netflix, Disney+, Vudu, etc.) as well as from my Blu-ray and DVD player connected to the TV via HDMI.

My new Roku Streaming Stick 4K is also connected directly via HDMI, but it will only output PCM stereo no matter what the setting. Right now, the audio output on the Roku is set to "Auto," but I have tried every combination to try to force the stick to output surround sound to the TV for pass-through to optical out, but nothing works. My older Roku model is able to output to the TV  and pass-through surround sound via optical with no problem (as well as the devices/apps I mentioned earlier), but this new stick only outputs PCM stereo.

Does anyone know how to force the Roku Streaming Stick 4K to output 5.1 surround sound via HDMI for pass-through to the TV to optical to the receiver? This is extremely disappointing and makes me want to try another streaming device.

[rdesalvo]

I discovered something unusual while trying to solve this problem. All of the Roku apps that I tested would only output PCM stereo to the TV to pass on to the optical cable to the AVR with the notable exception of HBO Max. The latter was the only app that I found on Roku that still passes 5.1 Dolby Digital surround sound through the TV to the optical out to the AVR. I kept the Roku audio settings the same (Auto/Custom: Dolby Digital and DTS on), and only HBO Max came through. So maybe the company behind each app has stopped supporting Dolby Digital and DTS... except for HBO Max? Not sure...

[atc98092]

Some (many?) TVs will not pass 5.1 audio from external devices out via optical. Internal apps on the TV will pass 5.1 just fine, but not anything connected to an HDMI port. That doesn't explain why HBO Max snuck some surround in there, though. But it is a common complaint that I've heard from many users that connect to the TV and use the optical out to an AVR or soundbar. But it's not a Roku issue, it's the TV. 

The only for certain solution is to either send the sound to the AVR via ARC, or connect the Roku directly to an HDMI port in the AVR. Of course, either solution requires an AVR/soundbar with HDMI connections. 

[UserOfStreamers · Accepted solution]

@rdesalvo 

DD+ (EAC3) has been around for nearly 20 years, and superceded DD (AC3) 10-15 years ago.  The DD+ bitstream is not inherently backwards compatible with DD, though devices with DD+ decoders can transcode/convert DD+ to DD for output (with limitations, depending on device).

Most streaming services/apps (e.g. NetFlix/Prime/Disney+/Hulu) use DD+ (EAC3) exclusively (other than AAC 2.0 converted to PCM 2.0 on device), so in order for DD (AC3) to be passed via Optical (Optical only officially supports DD, not DD+) either the streaming device or the device it connects to (AVR/TV - TV in your case) has to be able to transcode/convert DD+ to DD from HDMI>Optical (this requires a Dolby decoder).

However, from your description your TV cannot (or is not currently configured) to do this, though it doesnt explain "your older Roku", unless its a model 4640 (2016 Ultra - it has a Dolby decoder, like the new 2020/2022 Ultra - model 4800/4802).

There are some streaming services/apps (e.g. YT/YTTV/HBOMax/Paramount+/Apple TV/The Roku Channel) which can either do both DD+ and DD or only DD (depending on device detection/configuration), in which case as long as a device can passthrough DD from HDMI to Optical you will be able to experience their content in 5.1.

If Settings/Audio/Digital output format = Auto and "formats detected" = DD (not DD+) then your TV does not support DD+ passthrough from HDMI (just DD), in which case most/much streaming content will only be in PCM 2.0 (aside from the services/apps listed above), since the SS4K has no Dolby decoder (transcodes/converts DD+ to DD), and your TV doesnt support transcoding/converting DD+ from HDMI to DD for Optical.

Assuming you want to keep your TV and AVR, your best solution would be to get a model with a Dolby decoder, such as the Ultra 2022 (4802) or Ultra 2020 (4800), which can trasnscode/convert DD+ to DD for output via HDMI and allow Dolby 5.1 from all streaming services (regardless if they use DD+ or DD).

I recommend returning the SS 4K/4K+ and obtaining the Ultra 2022 (4802) instead for your situation.

Otherwise, many competitors' products have Dolby decoders, including the FS4K/FS4KMax, TS4K, O4KSB, and NS (the GCCWGTV does passthrough only like the SS 4K/4K+ so you want to avoid it).

FYI, there is an even newer Dolby codec intended to supplant DD/DD+ (AC3/EAC3) - AC4 (no known trade/brand name yet), and it is supported in some products, including the 4800/4802.

[rdesalvo]

Thank you so much for this info. I am going to return my Roku Streaming Stick 4K to Amazon and replace it with a Roku Ultra 2022 4K, which will decode the sound into Dolby Digital for me to passthrough to the AVR via optical.

[UserOfStreamers]

@rdesalvo 

When you get your 4800/4802, I recommend the following settings:

1) Disable HDR Always on:  Settings/System/Advanced system settings/Advanced display settings/HDR always on = Off

2) Enable framerate matching:  Settings/System/Advanced system settings/Advanced display settings/Auto adjust display refresh rate = Enabled

3) Enable audio passthrough:  Settings/Audio/Digital output format = Passthrough  (This will still convert DD+ to DD)

[rdesalvo]

I configured the audio pretty much as you described for my Roku Ultra. I noticed that if you try to force the Roku to send Dolby Digital to the TV when only a PCM stereo source is available (like the Spectrum TV app), the AVR will display a Dolby Digital 5.1 light indicator but if you check your rear speakers there is no sound whatsoever. So it may say Dolby Digital 5.1, but people should be wary and not be fooled. If you select "Passthrough," as you said, most programming on Hulu, Netflix, Disney, etc. will be transmitted to the AVR in 5.1 sound if the original source had it. Spectrum and older programming on other services comes through as PCM stereo with "Passthrough" selected, but that's fine because it sounds better than the "fake" 5.1 signal if you force the Roku to do so.

[UserOfStreamers]

@rdesalvo 

Yes, the Auto/Custom settings transcode/convert all audio to either the highest detected (Auto) or configured (Custom) Dolby level - this can/does result in volume, latency, dropout, empty channels, and channel mapping issues (as you discovered).

2.0 channel sources (e.g. Spectrum TV) are mapped into the L/R channels (with empty center/rear/sides/etc) of a 5.1+ Dolby encoding, thus precluding surround/upmixing at the AVR/SB.

Its a real DD/DD+/DD+Atmos signal, just encoded in device with the empty channels/channel mapping (precluding surround/upmixing in the AVR/SB).

As a general rule, you want the last/best device in the HDMI/digital/signal chain to the decoding, since its usually the most capable, and can apply any desired surround/upmixing/processing that the user wants (there are exceptions to this rule, especially when using a newer TV and an older legacy DD-only/Optical-only AVR, as you discovered), so that means using a passthrough/bitstream setting as much as possible in source and intermediate devices.

[TG101]

@rdesalvo 

PLEX works too.