Like I said before, yes you can. I previously only had one optical input on my sound system and wanted to use both a media pc and the xbox on it. So I had my optical cable go from the xbox to the optical input on the pc, then from the optical output on the pc to the sound system. Only think you need to change is the passthrough setting in windows when you want to use the xbox. Works perfectly and then you don't have to switch cables the whole time.
Yeah but I don't have a optical input on my Logitech X530 sound system, thats the problem.