i have the same speakers. but bought the mp3 audigy. it has the surround mixer. does your oem card came with that prog? it is needed to set your speakers to different modes (2.1 4.1 or 5.1 dolby digital). n also it can test all the channels.
one time, the test failed. my front right speaker died. i had to return the 5300. wit the replacement, everything is fine now.
so if u have the surround mixer program, turn on 5.1 mode, n hit "test." you'll hear a lady's voice announcing "front left, center, front right, rear left, rear right"