Forum Discussion

rdesalvo's avatar
rdesalvo
Binge Watcher
4 years ago
Solved

No Dolby or DTS Surround Sound Output Via Optical on Roku Streaming Stick 4K (2021)

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 D...
app playback
  • UserOfStreamers's avatar
    UserOfStreamers
    4 years ago

    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    DD+ (EAC3) has been around for nearly 20 years, and superceded DD (AC3) 10-15 years ago.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's avatar
rdesalvo
Binge Watcher
4 years ago

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...

UserOfStreamers's avatar
UserOfStreamers
Roku Guru
4 years ago

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's avatar
    rdesalvo
    Binge Watcher
    4 years ago

    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's avatar
      UserOfStreamers
      Roku Guru
      4 years ago

      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's avatar
        rdesalvo
        Binge Watcher
        4 years ago

        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.