Would love to have a definitive answer on 5.1 Surround sound with Mac Pro

Discussion in 'Mac Pro' started by aygie, Jul 4, 2008.

  1. aygie macrumors regular

    Joined:
    Oct 27, 2007
    #1
    Hi guys

    I have my mac pro hooked up to my Amplifier, an Onkyo 805 via DVI>HDMI and an optical cable.

    Now i thought that this would be giving me 5.1 sound (which i think it does when playing DVDs) but with Quicktime files with 5.1 it seems that only 2 channels of audio are playing.

    I've tried the bitstream trick (Perian + Change the Plist file) and this seems to work fine for AC3 audio but not AAC, so my questions are as follows....

    1. Is there anyway of bitstreaming all types of audio to the amp? (would this even work?)

    2. What is the best way to convert AAC to AC3?

    3. Would a dedicated 5.1 sound card be better than the optical cable? If so do any exist!?!?

    The main reason why i ask all of this is because i downloaded this http://downloads.dvdloc8.com/downlo...dc018ba6126/ReVsj5wI/dolbydts/dolbycanyon.zip

    (its just a short trailer for Dolby Digital with 5.1), played with VLC and it sounded ok, then went and selected use S/PDIF in VLC and it blew me away! Its got me thinkg that maybe i'm not using my system to its full capabilities.

    Thanks for your help :)
     
  2. H00NER macrumors newbie

    Joined:
    Nov 13, 2007
    #2
    Quicktime applications do not provide true passthrough of digital audio. Instead, your amp is receiving a 2-channel PCM signal. At one point, one was able to send a multichannel digital signal through Quicktime applications using Perian's passthrough setting, but this was broken with one of the past updates to Quicktime. Many people have been petitioning Apple to fix this, but it is believed that this may be a restriction related to requiring AppleTV in order to get true 5.1 surround sound. See the following page for more on how to petition Apple to fix Quicktime. At present, as you have already discovered, the only way to get digital passthrough of AAC audio is to use VLC. You can usually tell when you are getting a true 5.1 digital signal because an indicator on your amp will no longer display "PCM" but instead a Dolby Digital or AAC indicator will illuminate.

    http://www.cod3r.com/2008/03/wheres-real-ac3-passthrough-on-the-mac/

    When playing games, the sound is again a 2-channel PCM audio signal. Recently, some motherboards and audio cards have begun to support a standard called "Dolby Digital Live", which takes 5.1 analog audio signal and converts it on the fly to a digital signal that can be sent over digital optical or digital coaxial cables, thereby providing true 5.1 or 7.1 surround sound. Most people do not realize that they are not getting true surround sound when playing games in either Windows or MacOS.
    I currently have a Asus Xonar D2X card for audio in Windows installed on my MacPro. This card supports all standards, including Dolby Digital Live, for digital audio. The card is connected to my Onkyo receiver via a digital optical cable.
     
  3. aygie thread starter macrumors regular

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    Oct 27, 2007
    #3
    H00ner, thank you for your post, very informative.

    VLC at the moment is the best choice, however it has started to crap out on me big time. It won't play .mov or MP4 files, just crash on start up. Other files are strangely ok in it though :confused:

    Such a shame that Apple a like this. Having some of the best video/audio editing programs and you can't even get audio passthrough is ridiculous.

    Thanks for your links, they are added to my bookmarks :)
     
  4. Siron macrumors 6502

    Siron

    Joined:
    Feb 4, 2008
    Location:
    North Carolina
    #4
    I have a SoundBlaster XFi PCIE card and in Vista 64 it provides 5.1 in games. Unfortunately I cannot get it to work in XP as there are no XP driver. I guess it's a Vista card only.
     
  5. aygie thread starter macrumors regular

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    Oct 27, 2007
    #5
    Sorry but i'm not too hot on cards, so you can stick any type of PCIE card in the mac and it will work on the windows side and be ok when you run Leopard? (as in it wont interfere or cause any damage?)
     
  6. Siron macrumors 6502

    Siron

    Joined:
    Feb 4, 2008
    Location:
    North Carolina
    #6
    Yes you can install any PCIE card. It will only work in OSX if there is a driver available - if not then Leopard will ignore it just like it does with Windows video cards. The X-Fi sound card is for Vista only. I have a 4 port USB PCIE card that works in OSX, XP and Vista.
     
  7. aygie thread starter macrumors regular

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    Oct 27, 2007
    #7
    Ah, good to know, thanks
     
  8. H00NER macrumors newbie

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    Nov 13, 2007
    #8
    VLC still works for me, but sometimes it switches the system sound settings to internal speaker.
     
  9. MacsRgr8 macrumors 604

    MacsRgr8

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    Sep 8, 2002
    Location:
    The Netherlands
    #9
    I have got this Soundblaster X-Fi PCI-e card in my Mac Pro '08 (8 x 2.8), and both Win XP (SP 2 and SP 3) work very well with it!
    I am having major fun playing Colin McRae DiRT in 5.1 audio after finally finding a workaround the 8-Core issue... :)
     
  10. DeuceDeuce macrumors 6502a

    DeuceDeuce

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    San Dimas, CA
  11. Siron macrumors 6502

    Siron

    Joined:
    Feb 4, 2008
    Location:
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    #11
    Where did you get the drivers for XP? I cannot find then anywhere.
     
  12. MacsRgr8 macrumors 604

    MacsRgr8

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    Sep 8, 2002
    Location:
    The Netherlands
    #12
    I installed them from the installation-CD, and used the Creative Auto-Updater to keep them up to date.
    Did you get the black X-Fi Extreme Audio PCIe Installation CD?
     
  13. Siron macrumors 6502

    Siron

    Joined:
    Feb 4, 2008
    Location:
    North Carolina
    #13
    I think so but why wouldn't an XP driver be available on their web site if it's on the CD? Strange :confused:
     
  14. MacsRgr8 macrumors 604

    MacsRgr8

    Joined:
    Sep 8, 2002
    Location:
    The Netherlands
    #14
    I have no idea..?
    Pretty weird on Creative's part.... I just looked as well, and the drivers for XP seem non-existant.. :confused: (see pic)

    Still, installing from CD works, and so does the auto-updater. Just make a safe copy of the Install CD! :eek:

    IIRC in my old gaming P4, I had the Soundblaster Audigy 2 PCI card, and I remember having trouble finding all the drivers back then too.... I usually ended up installing from CD and keeping on updating.
     

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