I am currently getting the Logitech Z-5500's and all I have is crappy integrated sound, I know I want to buy a new sound card, but I'm not sure how much to spend. Do I need S/PDIF out or Digital or both. I mainly play music, and will now watch movies once I get these speakers, no gaming though, sorry that upsets a lot of you, lol. I know these speakers have a digital decoder but i'm not really sure what that means, any advice/help anyone could give me would be greatly appreciated.