Configure 5.1 audio out on Mac Pro 5,1?

Discussion in 'Mac Pro' started by choreo, Feb 16, 2017.

  1. choreo macrumors regular

    choreo

    Joined:
    Jan 10, 2008
    Location:
    Midland, TX
    #1
    I have a 2012 Mac Pro 6-core tower that has a built-in optical audio out jack.

    I just ordered a Logitech Z906 set of 5.1 Surround Sound THX speakers with controller. I am assuming that I will be able to connect an optical cable directly between the Logitech controller and the Mac Pro, but how
    "exactly" do I get the Mac to send out true 5.1 signal vs standard stereo?

    I have searched the Internet an YouTube and everything I find is confusing or contradictory.

    Anyone have any advice?

    THANKS!
     
  2. xWhiplash macrumors 65816

    Joined:
    Oct 21, 2009
    #2
    I have the same speakers! I could never figure this out. Whenever I watch iTunes movies, I set it to "Prefer AC3 Passthrough" or something like that. Then it sends 5.1. Not sure what to do if you are outside of iTunes though.

    I think it just depends on the content. Because, Windows 10 and my other computer do the same thing. I need to be in either Netflix or something that supports 5.1
     
  3. profdraper macrumors newbie

    profdraper

    Joined:
    Jan 14, 2017
    #3
     
  4. choreo thread starter macrumors regular

    choreo

    Joined:
    Jan 10, 2008
    Location:
    Midland, TX
    #4
    After further investigation, it appears that the MacPro does not support 5.1?
     
  5. profdraper macrumors newbie

    profdraper

    Joined:
    Jan 14, 2017
    #5
    Have been using a Logictech Z-5500 in a recording studio without fuss for many years now. Should be the same or similar tech as the Z906 brain (?) You don't give any information as to how you expect to use the system (i.e., consumer playback & of what exactly, vs. your own original production etc). However, my experiences are as follows:

    1) Yes, simply connect the optical cable for playback. When playing say a DVD with surround sound, the Logitech decoder will play this as per the given supported codec (THX, Dobly Digital etc). That is, the surround decoding playback is dependent on the manufacturer of the DVD, not the user. Balance the speakers, rears & subs via the remote.

    2) For playback of stereo sources, there are number of 'FX' available on the Z-550 where 'dual stereo' etc can be simulated for a reasonable fake experience. Also NB that the Apple Audio MIDI setup CP has config. settings for both stereo and surround (but I have found no reason to need to use that in the a consumer optical scenario where the decoder does all the work).

    3) For original surround sound audio production, the Logitech brain has numerous analogue inputs (and which can be manually routed to the optical outputs) - that FX is called 'direct mode' where the inputs are routed to the outputs according to whichever surround convention is being used for authoring (I'm using the ITU spec: L-R-C-LFE-Ls-Rs). This also means the studio computer requires a suitable multichannel audio interface to provide all those analogue outputs, say, a stereo pair for downmix reference on main monitors, plus another six outputs for 5.1 i.e., an eight output interface which is quite common.

    Hope that helps.

    MacPro 5,1 12x3.33gHz, Sierra, UAD Apollo + RME ADI-8, SE Munro Eggs, Genelecs, Logictech Z-5500
     
  6. thornslack macrumors regular

    Joined:
    Nov 16, 2013
    #6
    It supports it. Your source material must also be multi channel audio and your playback software must also support multichannel decoding. I typically use VLC.

    Here I get a little fuzzy cause it's been a while but I think this is the set up:

    Under Audio MIDI Setup, select built in digital output and select a 2-channel integer option. I *think* this is correct, but if I am wrong then the correct option is the Encoded Digital Audio option. Then in VLC under Audio Output select Built in Digital Output (encoded Output) and you should be good to go.
     
  7. xWhiplash macrumors 65816

    Joined:
    Oct 21, 2009
    #7
    It supports it. Just launch iTunes if you have any movies or TV shows and choose "Prefer AC3 Passthrough". It will be 5.1
     

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