Hi, I have an old sony stereo that has dolby pro logic. I have it hooked up to my pc with 2 regular a/v cords. Im new to surround sound but have a pretty good idea that it works with cds from the cd player on the recever since I can hear out of all the speakers. What I wonder is if the stereo is correctly processing the dolby pro logic when it is connected to my pc. I have downloaded some mp3 files that say they test dolby digital but they do not work correctly with all 5 speakers. So I am wondering if I need to buy anything extra to get my stereo surround sound to work with my pc.