Hello, I'm not sure if this is the right place to post this but I'll give it a try. I currently have XBMC Eden 11 software running on my iMac (late2007) on 10.6.8 Snow Leopard and am trying to figure out how to get 5.1 audio to stream through the computer and my stereo receiver. I have my settings on XBMC set to receive it through my optical output but the only sound I get to hear on my sound system is PL2 (ProLogic II). I know that my Mac will play 5.1 audio when playing DVDs while using the DVD Player app. I have read some posts that setting up Quicktime to passthrough the DD signal will work but also that it will disable other audio signals if they are not 5.1. I'm confused about changing the settings on Quicktime described in this link. http://www.cod3r.com/2008/02/the-correct-way-to-enable-ac3-passthrough-with-quicktime/ I don't know if it XBMC uses Quicktime for it's audio decoding or if there is another codec out there that needs to be downloaded for my iMac since I don't think it is an XBMC thing. I've got a DVI connector with an adaptor going to an HDMI to my TV for the picture. Using the remote I set it up to play XBMC and blank out my display while watching programming. Does anyone know what I'm talking about? I've posted a similar question on the XBMC forum and have not had any replies as of yet. Thanks if can help or enlighten. Next stop, Apple Forums.