I have looked through the threads here ENDLESSLY!!!! And I, unfortunately, still seem to be at a loss on what to do. As of right now, I have a headphone output going to the Red and White RCA analog to my surround sound input just like the ones here The headphone male end is going into the very far left headphone jack of my iMac. I have a 5.1 surround sound system and I know that this isn't being used to it's full potential. I am not fully sure on what to do with the Audio in / optical audio in port... If I connect a fiber optic cable to that into my digital input on my surround sound, is that all I need? (this?) No RCA plugins or anything....? Also, I have read endlessly on the FireWave and I am not really sure what the point of that is...? I don't know how it comes into play with hooking up my surround sound system to my iMac. I have the Sony HT-DDW670 Thanks guys, I'm a newb here too btw.