DTS Not Working through Optical

Discussion in 'HDD Media player(RTD 1619DR)' started by Nicholas Hewitt, Feb 27, 2021.

  1. If I use my TV's optical port, everything works as intended. If I use the optical port on the ZX9 eveything works except for dts. I really want to use the port on the Z9X though. My DAC-AMP Combo supports Dolby Audio, so I set my TV Optical to Dolby Digital, and it plays whatever gets thrown at it. With the Z9X I think I've tried every setting and combo to get sound in the dts audio tracks, but nothing works.
  2. turbomaxBG

    turbomaxBG New Member

    DTS is not support in optical
  3. Sarco

    Sarco Active Member Beta test group

  4. Markswift2003

    Markswift2003 Moderator Beta test group Contributor

    Sorry to correct, but DTS is supported over optical and I've just tested the Z9X optical port and it will pass AC3 and DTS signals fine.

    But to be clear, that only applies to standard DTS.

    S/PDIF links (ie optical) do not have the bandwidth to support lossless formats such as DTS-HD and DTS-X, or indeed Dolby TrueHD or Atmos.

    If you are trying to play a DTS-HD soundtrack over optical then set Downmix HD Audio to <on> in Audio settings.

    This doesn't really "downmix" the audio since the device doesn't have a licence to do so - what it does is enable the lossy DTS core track within the DTS-HD wrapper to output over the optical link - again, just to be sure, I tested this and it works.
    andreamusso.am and ammar11 like this.
  5. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Added this to the recommended settings.

    Warning: not all HD DD and DTS tracks have a compatible core included as far as I know.
    ammar11 likes this.
  6. ammar11

    ammar11 Active Member

  7. Markswift2003

    Markswift2003 Moderator Beta test group Contributor

    ammar11 likes this.
  8. ammar11

    ammar11 Active Member

    True, it's a separate AC3 track embedded in the TrueHD stream. It doesn't work in MKV container, so it's always stripped off into a separate track when we rip it from the disc.

    For dts-HD Master Audio the core DTS track is part of the main stream, so we more likely to get it in an MKV stream.
  9. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Thanks! Added this to the post too.
  10. Paul777

    Paul777 Member

    You mean that AC3 is located inside DTS-HD MA core?
  11. McBluna

    McBluna Active Member

    @Paul777 AC3 is Dolby Digital and not DTS
  12. Whitfield

    Whitfield Active Member

    Wouldn't that mean MakeMKV can mux DTS-HD MA stream without a core? I highly doubt that.

    Maybe a short explanation about TrueHD and DTS-HD MA and their usage will clarify.

    DTS-HD MA is built on a lossy dts core. This core is for legacy reasons. Next to the core is additional, core-dependent data. The core + extra data together make the lossless Master Audio stream.
    These kind of tracks are used on (UHD-)BD and can be directly muxed within mkv as one track. You can choose to mux the whole HD stream or just mux the core, as this core is independent.

    Dolby TrueHD audio is one independent stream. There is no core. (UHD-)BD spec state that TrueHD audio must carry an embedded AC3 track (also, for legacy reasons). So, the main difference as to (UHD-)BD authoring, and compared to DTS-MA, is that there are two, both independent streams within one "TrueHD" audiotrack.

    Mkv, because of its construct, can't have two audiostreams as one track. You can mux either one, or both as separate tracks.
  13. ammar11

    ammar11 Active Member

    You are right. I came to that idea when I saw this in MakeMKV, but I never tried. I guess it just extracts the core track without actually altering the original dts-HD MA track.

    Give me a minute, I'll do a test rip.
  14. ammar11

    ammar11 Active Member

    Alright, so this is the Mrs Doubfire disc.


    Ripping with the sub dts audio creates a new lossy dts track without altering the original lossless track.


    So this is how MakeMKV works (based on the MKV specs that allows only one stream in one track):

    dts-HD Master Audio - option to extract the core lossy stream (because the core dts is part of a single stream, the original will always be untouched)
    Dolby TrueHD - option to extract the embedded lossy stream (because the AC3 is embedded as a different stream it will always be removed)
  15. Yeah I mean plain dts! It's not working at all on my player. AC3 works fine.
  16. Markswift2003

    Markswift2003 Moderator Beta test group Contributor

    Just realised - you're using the TV optical port - not all TVs support DTS.
  17. DTS over optical is sure supported (HD formats not of course, only if downmix works)..
  18. Whitfield

    Whitfield Active Member

    Does it support dts too?
  19. Like I said the dts Plays fine when I use the TV optical port, but not the players optical port.
  20. Paul777

    Paul777 Member

    Sound is not important as video. For movies and TV shows video is more important than sound. Keep it in mind.

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