there are a number of speakers u can look for at your budget range. i suggest u can go and try them out first using the same source. if u r using a notebook, then perhaps u can use your notebook to hook them up so u can try out which one is nicer to your ears

i have heard the altec lansing MX5021 (thx certified - i might be wrong on the model no.), the bass is hard thumping and clarity is there. but i'm not sure on the edifier 330.

One more aspect u need to consider is that the soundcard u r using. If soundcard is a good one, perhaps rm500 and beyond, then u have to look for a better pair of speakers.

creative x-fi surround 5.1 is an average soundcard. i have 1 hooked up to my notebook. Definitely much better than the built in sound. I used the rca-rca stereo cables made by yeahs4.1 to hook to my razer mako 2.1.