Not really sure whether this is hardware or software, so firstly sorry if its in the wrong place!

OK, i have got a 5.1 speaker set up at the moment and all the software on my machine blasts it out on all 5 speakers EXCEPT when i play music on iTunes, where it uses the front two speakers. Im guessing this is because they are MP3's and thus in stereo format, but is there anyway i can change the settings so that it simulates surround sound? Basically what i want is noise coming out of all 5 speakers!

Cheers guys