Mac Pro and 5.1 Optical Amp

Discussion in 'Mac Pro' started by costabunny, Aug 20, 2008.

  1. costabunny macrumors 68020

    costabunny

    Joined:
    May 15, 2008
    Location:
    ~/bunny/
    #1
    Ok, maybe I am being silly here, but I think I read that the mac pro pushes 5.1 out of the optical port. So I finally found my optical cable and hooked it up to my Sony 5.1 Receiver (I tested the cable from the Denon DVD first and surround is perfect).

    I have a bunch of surround test wavs that I use (FR, FL, Centre, RR, RL), but only the FR, FL and Centre are being directed out of the correct speakers. The RR and RL still comes out of the FR and FL speakers.

    I am a bit confused as I cant seem to find any config for the surround output.

    Does anyone here have an idea as to whether I am mistaken about the audio capabilities or if I am missing something?
     
  2. scottydawg macrumors 6502

    scottydawg

    Joined:
    Jan 22, 2008
    Location:
    Sacramento, CA
    #2
    From everything I have read the MP only has stereo audio on any of it's ports.
     
  3. costabunny thread starter macrumors 68020

    costabunny

    Joined:
    May 15, 2008
    Location:
    ~/bunny/
    #3
    Well just to make sure I am not going completely foo-foo, I have just dug out the manual for my Mac Pro :

    Optical digital audio in and audio out ports
    Connect to decks, receivers, digital instruments, and 5.1 surround-sound speaker systems using standard TOSLINK cables or fiber-optic cables with a 3.5 mm plastic or nylon optical plug. You can transfer stereo or encoded 5.1 audio using the S/PDIF (Sony/Philips Digital Interface) protocol and TOSLINK cables

    So now I know the first bit of my question I need to figure out why it isnt giving proper surround? I have tried many configs on the Amp (of which there are a plethora) but mainly the ASF.D auto (the one I prefer as the Amp makes its mind up about the source protocol. That works fine on the Denon DVD.

    .....a confused wabbit..... :confused:
     
  4. Cave Man macrumors 604

    Cave Man

    #4
    Dude, if you don't know what you're talking about, you shouldn't respond. ;)
     
  5. Cave Man macrumors 604

    Cave Man

    #5
    Optical out will passthrough whatever is encoded in your media (even more than 5.1). It can be analog or digital, but if you want digital (e.g., Dolby Digital) then the file you're using must be encoded in digital. What is your media source and does it have such content?
     
  6. Peace macrumors P6

    Peace

    Joined:
    Apr 1, 2005
    Location:
    Space--The ONLY Frontier
    #6
    Open those .WAV files using QT and look at the info. If it says 5.1 audio set your amp at "auto". That's what I do with my MacPro connected to a Yamaha receiver and I get 5.1 audio when the original source is 5.1.

    Another thing to try :

    Put a DVD that has 5.1 Dolby in your Mac and play it. The 5.1 audio should play.

    I watch HD over-the-air TV every night and the toslink cable sends 5.1 signals to my receiver and it sends out 5.1 audio.
     
  7. Cave Man macrumors 604

    Cave Man

    #7
    You have to make sure DVD Player app is set to output digital before putting in a DVD.
     
  8. costabunny thread starter macrumors 68020

    costabunny

    Joined:
    May 15, 2008
    Location:
    ~/bunny/
    #8
    hmmm ok thn - bit of a good find. I grabbed a DVD (star Wars ROTS) and played in VLC (the only player in my opinion) and no sound from the RR,RL :(

    so I forced the Amp into ProLogic mode and w00t some sounds :) quick look in VLC's Audio menu found an option to choose the output destination (Optical was already selected) but (and here's the important bit)<yoda voice> there is another </yoda voice> option labelled Optical Out (encoded) - Hazahhh then the satalites burst into 5.1 digital gloriousness :)

    Happy Bunny

    (maybe my test wav files are not 5.1 digi encoded but 5ch analog instead?) oh well at least I have my surround working in all its digital wonder!


    ...happy wabbit.....
     
  9. costabunny thread starter macrumors 68020

    costabunny

    Joined:
    May 15, 2008
    Location:
    ~/bunny/
    #9
    DVD player app ? nah not getting you - there is only VLC? surely there isnt another app in the universe that people would consider usingto playback DVD's ?


    (Just messing with ya... Thanks for all the help EVERYBODY)

    :)
     
  10. Cave Man macrumors 604

    Cave Man

    #10
    Pro Logic will not give you digital 5.1 surround. Your receiver needs to be able to decode Dolby Digital to get it. Pro Logic is principally an analog mode (DPL = 4 channels, DPLII = 5 channels).

    For the discrete 5.1 digital from that DVD (which is encoded in Dolby Digital 5.1) you need to (1) launch DVD Player app without a DVD inserted, (2) make sure your receiver is on and it is set for optical from your Mac's connection input, (3) in DVD Player choose Preferences>Disc Setup and under audio you should have an optical (or digital?) output option, and (4) insert and play the DVD. On your receiver, the Dolby Digital indicator (usually 'DD' with the first 'D' backwards) should illuminate. If that does not occur, then you are not getting DD 5.1 surround sound.
     

Share This Page