Nice setup. However, for $350, you could have gotten a nice 5.1 Onkyo Home theater setup that would have sounded a LOT better. Computer speakers are poor quality compared to bookshelf/tower home speakers.
I have a 2.1 Sony setup hooked up to my computer right now. Sony speakers aren't spectacular, but these still sound better than any computer speakers I've heard, including the Z-5500's. Here is bass video I made. First song is the same some you used . Also the quality isn't great but you'll be able to hear it fine.
http://www.youtube.com/watch?v=4dU45a4y4uA