Hi, I have read many posts regarding this issue, but I can't find a solution that has been said to work. I have a 21.5" 2011 iMac running lion with Logitech X530 speakers. I would like to get surround sound working for movies, has anyone had any success with this? I understand I may need an external sound card or possibly an adapter of some sort, but I am unsure what is required that will work on the mac system. I do not run windows, only mac os. Thanks in advance!