Surround Sound with Existing 7.1 Speakers

Discussion in 'iMac' started by IMJ, Jun 13, 2011.

  1. IMJ macrumors newbie

    Jun 13, 2011

    (I did do a search and found several threads about surround sound but none of them seemed to have any conclusive answers, so apologies for the new thread!)

    I'm a long-time PC user and have just ordered one of the 27" 2011 iMacs. One thing I have yet to work out is exactly how to get surround sound up and running. I will be installing Windows 7 with Boot Camp to play most of my games on, so really my priority is to get surround sound working in Windows. If it works under MacOS as well then that's a bonus.

    My existing PC has a Creative Labs Inspire T7900 7.1 system with ordinary analogue inputs (Green/Black/Orange output from soundcard, Green/Black/Orange/Grey input to subwoofer unit), and ideally I would like to keep those speakers rather than buying new ones. I know that the only standard way of getting surround output from an iMac is through the optical port. So what I need is either:

    • An adapter that accepts optical input and outputs to 3-port analogue. (I'm not even sure if such a device exists?)
    • An external USB sound card with the analogue outputs.

    Although it would be nice to get the full 7.1 output, I'd be happy with 5.1, and again, Windows is my priority. Are there any devices that would solve my problem, or am I going to have to buy a new set of speakers with an optical input?

    Any help would be much appreciated. Thanks!
  2. 5piN macrumors member

    Dec 11, 2010
    Not sure you are going to have much joy getting any surround sound from games....

    I've spent the best part of the last month trying to get this working. Unfortunately games only output surround to discrete channels, you are out of luck on the standard iMac and would need an external card with connections for the discrete channels (Green/Black/Orange)

    The alternative route would be optical (which is what i use) ..... which will only work in games if the sound card could encode to 5.1 on-the-fly be Dolby Digital or DTS... once again we are out of luck.

    Fortunately dvd's and ac3 encoded videos are fine with optical, using spdif pass-through .... assuming your amp can decode the signal.... applications like Plex, VLC, Quicktime with Perian have no problems giving the full surround spectrum....

    If there was a piece of middle-ware software that encoded the sound and then send it to the speakers in games it would solve the problem! ... albeit there would be a slight CPU overhead for the processing (some motherboards advertise having DD and DTS but do the all the encoding in software, so is possible)... I've tried using ac3filter in Bootcamp but only run into a brick wall ....

    Those are my thoughts on the topic so far, maybe somebody has had more luck then me....:confused:
  3. IMJ thread starter macrumors newbie

    Jun 13, 2011
    So it's definitely looking like I need an external sound card.

    After doing some more research, it would appear that the Creative Labs X-FI Surround Pro would work fine in Windows and allow me to play games in 5.1, is that correct? It may not work in MacOS but that's not the end of the world.

    There's also the Sweex 7.1 External USB Card which is 7.1 and a lot cheaper, but given that I've never heard of the brand I'm a little suspicious.

    Anyone have any experience of either of these devices (or any other alternatives)?
  4. kitsunestudios macrumors regular

    Apr 10, 2012
    Diamond multimedia makes a Mac-compatible USB 7.1 surround system. You can probably find it at NewEgg for around $30

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