TWC Digital Audio problem, need help.

Discussion in 'Archived Threads 2001-2004' started by Joe Brasi, Mar 6, 2003.

  1. Joe Brasi

    Joe Brasi Auditioning

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    I have the standard TWC (General Instruments) STB box. I have a Digital cable running from Digital Audio Out (SPDIF) on the STB into the Coax 2 (In) on my Onkyo receiver. So I have now eliminated all audio connections bewteen the box and the receiever except for the Digital cable.

    The problem is I can't get the receiver to recognize DD 5.1, 2.0, etc. or any other Dolby Digital format on anything, channels >100 PPV, HBO, etc. The receiver DOES display the PCM digital light on the display recognizing that sound is coming in from the Coax 2 Digital Input. Receiver is set to receive DIGITAL from Coax 2. Sound does come through the stereo. However, I CAN't select any DD formats and the Dolby Digital light is NOT on. The ONLY formats I can select are Stereo, DPL, 5 ch. Stereo, and all the other analog DSPs that you get with normal TV. It is NOT recognizing a Dolby Digital source.

    Possible problems...

    A. A SETUP issue with the box. Although I see no way to enable DIGITAL AUDIO OUT on the menus. ONLY STB audio menu options are Stereo, Matrix Stereo, and TV.

    B. I'm completely insane. I've checked the wiring 10 times and it is correct. Hell, there is only one wire. So am I correct in saying that TWC is sending a Dolby Digital signal that my receiver should recognize and display? Or am I completely off base here with what my receiver is doing?

    PLease help me out if you can. I've gone almost a week like this and I'm completely frustrated with it. Thanks guys.
     
  2. David E Smith

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    After lots of fiddling around, I decided that the PCM signal is digital. It in fact is. The catch is that although TWC may even SAY that you get Dolby Digital, what you are really getting is Digital Dolby Pro-Logic sound. (or a digital 2 channel signal thats not in DD format, that DPL can be used with.) [​IMG]

    Another issue. Please correct me if I am wrong, but if there is no DD content being generated via the programming (show) comming in, then there will be no DD signal to decode. I am not convinced that TWC would forward that DD signal via cable anyway. I believe they do not, but I am not 100% on this. I would enjoy if someone could prove me wrong.

    The only way I have obtained true DD 5.1 sound via TWC was via the HD signal, for HD programming only. Everything else uses the PCM digital signal.

    Dave
     
  3. Michael Reuben

    Michael Reuben Studio Mogul

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    A few clarifications:

    PCM is indeed a digital format. It's the format used for CDs and most laserdisc audio (among other things).

    "Dolby Digital" does not mean "5.1". A Dolby Digital signal can contain anything from a single channel to five discrete channels, plus LFE. It is entirely possible, and indeed likely, that you are receiving DD 2.0 on most channels.

    DPL, in either original or "II" flavor, can be applied to ANY two-channel source. That includes analog, PCM stereo and DD 2.0. I suspect you're getting DD 2.0 and the receiver is automatically shifting into DPL processing.

    M.
     
  4. David E Smith

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  5. Michael Reuben

    Michael Reuben Studio Mogul

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    There are various possibilities. Your cable box (a model I'm not familiar with) could be converting DD 2.0 to PCM output. Or the "Dolby Digital light" on your receiver may not light up unless it's a 5.1 soundtrack (have you tried this with DD 2.0 DVDs?).

    As a practical matter, it doesn't make much difference. You wouldn't be able to do anything more with a 2-channel signal than you're already doing, regardless of whether it's PCM or DD.

    M.
     
  6. David E Smith

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