8 Replies Latest reply: Jun 1, 2011 11:59 AM by configment
levelg Level 1 Level 1 (0 points)
I've just got one of the new Mac Minis with an HDMI connector that I'd like to connect via a home theatre amp to be able to drive a 7.1 speaker system . I'm using a Onkyo TX-SR576, and the Audio Midi Setup program finds the HDMI device. It has the source listed as TX-SR576, and I can select the format (up to 192 kHz) and up to 8channels of 24 bit.

The problem is that I can't get any sound to go through. The Digital Optical link is working fine, but it's standard stereo.

Has anyone else managed to get 7.1 channel from a Minimac via HDMI? If so, what home theatre amplifiers work? Is there a restriction on which amplifiers can handle the 8 channel audio?

MacBook Pro, Mac OS X (10.6.4), Bootcamp
  • 1. Re: Outputting Multichannel sound through HDMI
    Jeff Bronstein Level 1 Level 1 (5 points)
    Im using the new Denon AVR-4311ci and have the same problem. Directly from iTunes all the Denon is seeing is Stereo.
  • 2. Re: Outputting Multichannel sound through HDMI
    configment Level 1 Level 1 (0 points)
    I think my problem is very similar.

    I am not getting the option to select multichannel digital audio output for my HDMI connection in "Audio Devices" window of "Audio MIDI Setup."

    I'm using the "Apple recommended" Griffin Video Display Converter for HDMI via Mini DIsplayPort with my mid-2010 MBP.

    It successfully outputs digital STEREO audio which plays on the speakers of my LG TV (a 42LD520). That's all fine and nice. But, I'm trying to take advantage of the LG TV's digital audio passthrough capability (to pass-through multichannel digital audio) and am having problems.

    Here's the setup I CANNOT get to work:

    1) Connect my new mid-2010 Macbook Pro to my LG TV (42LD520) via HDMI using the Griffin Video Display Converter.
    2) The LG TV (serving as a digital audio passthrough) is connected via TOSLINK optical audio output to my surround receiver (Sony BDV-E570... which, BTW only accepts digital audio input by optical or coax, NO HDMI)
    3) The Sony receiver decodes the multichannel digital audio (Dolby Digital, DTS, whatever), and everyone lives happily ever after.

    In fact, I've SUCCESSFULLY gotten this exact setup to work with a Roku player: the Roku is connected via HDMI to the TV, and the LG TV outputs (passes-through) the digital audio via optical TOSLINK to my Sony surround system (BDV-E570), which decodes and plays back the multichannel DD/DTS. Yippee. Straightforward. Clean.

    But, *DESPITE THE FACT MY LG TV ACCEPTS MULTICHANNEL DIGITAL AUDIO VIA HDMI*, OS X will NOT give me the option of outputting multichannel audio through the Griffin adapter to the TV via HDMI. I cannot select any multichannel output in "Audio Device Setup" for the connected HDMI. Why?

    I SUSPECT this is because OS X, after ID'ing the TV through EDID lookup, sees my LG TV as ONLY compatible to accept HDMI audio as 2-channel digital, so it doesn't give the multichannel output option--- (this, of course, totally ignores the purposeful use of the TV's digital audio passthrough).

    IF ONLY I could force OS X to override this "unnecessary" restriction and output multichannel audio through the Griffin adapter to the TV via HDMI. If I could, I bet this would all work.

    I REFUSE to run 2 wires and run a separate audio output from the MBP with one of those stupid USB+3.5MM TOSLINK adapters. It's dirty and shouldn't be necessary. The HDMI wire carries it all-- that's the point.

    So, in short, Is there a way to force OS X to output multichannel digital audio over HDMI?

    If so, I think it'd work. Thanks for any help!
  • 3. Re: Outputting Multichannel sound through HDMI
    woodmeister50 Level 4 Level 4 (3,745 points)
    If you are using any of the Quicktime based software players with anything
    other than iTunes store content you need to do this:

    http://www.cod3r.com/2008/02/the-correct-way-to-enable-ac3-passthrough-with-quic ktime/

    This will pass the Dolby and DTS material through. Note that the the Mini
    cannot passthrough any TrueHD or DTS-HD tracks at this time.

    If you use any other software players (I use PLEX myself for HD content)
    you should only have to make sure in MIDI Audio Setup that the output is
    set to stereo if source material is "encoded".
  • 4. Re: Outputting Multichannel sound through HDMI
    configment Level 1 Level 1 (0 points)
    woodmeister50, I've made your changes exactly... but it doesn't work-- still only digital stereo goes out over the HDMI.

    Is that because it only works for the optical out? (and not HDMI?) Or, does it not matter? Maybe you can update your post if your configuration only works with the optical audio out on the mbp...

    Still looking for a way to override the digital audio out on the HDMI to force multichannel digital audio when osx detects a 'non-multichannel compatible attached device.'
  • 5. Re: Outputting Multichannel sound through HDMI
    configment Level 1 Level 1 (0 points)
    When I sent this problem to Griffin, this is the speedy response I received from Griffin. Not helpful, though it seemed that they didn't deny this problem w/ OS X.


    Dear [valued customer],

    I'm not aware of any built-in software function of OS X that would force the output of multichannel audio. And, unfortunately, Griffin doesn't make an adapter or interface that would meet your particular needs, and I'm not sure where you would find the physical equipment and software that will do so. You are correct; all the necessary data for multichannel digital audio is carried by the HDMI cable. The problem is finding the correct physical and software interface to transmit and decode HDMI data in a format that can be used for multichannel output. There may be an adapter and software available to do that, and a good place to start might be gefen.com. This is, in our experience, a good resource for more specialized audio/video needs.

    I hope this helps. Please let us know if you have any further questions or if we can assist in any way.

    Thanks, and have a great day!

    Dylan Ross
    Griffin Technology
    Technical Support
  • 6. Re: Outputting Multichannel sound through HDMI
    KeaweWong Level 1 Level 1 (0 points)
    I had the same problem with my Mac Mini hooking up with HDMI to a Denon receiver. The solution is really simple if you know it. Install "soundflower". That's it. Really. Soundflower allows up to 16 channels pass through. I installed it and am enjoying many and many m4v movies from itunes with Dolby 5.1 surround sound. Enjoy

  • 7. Re: Outputting Multichannel sound through HDMI
    pnewelljr Level 1 Level 1 (0 points)

    Could you go into more detail about how to use Soundflower to achieve this?

  • 8. Re: Outputting Multichannel sound through HDMI
    configment Level 1 Level 1 (0 points)

    I couldn't get it to work, either. The HDMI is still limited in its output, so when you map channels from Soundflower to the HDMI, the HDMI has two channels.... see the image.


    Still here in this situation, the Macbook is still sensing the HDMI is only capable of 2-channels, and therefore when I try to route sound to it, it only gives two options.



    Also, I responded to this person's message with a longer post:



    Maybe there's something there??