Hello, I am a layman when it comes to audio. Basicly I am tired of my $50 5.1 system that my parents bought me 7 years ago.

I want to buy 2 decent speakers (and a sub? is that needed?) to put on my desk. I will listen to them from a short distance (near-field that is called?). I will not play anything loud since I have quite sensitive neighbours. I have an eclectic musical taste (i mostly listen to bass-heavy music like classic dubstep or drum and bass, but also metal, jazz and some other genres). I will play music from a PC and a laptop (both with some generic integrated sound cards). Is there any way to diminish the effect that those soundcards have on music? Like some external USB card or some device? Or is that unnecessary?
Basicly I want to get the best sound for maximum price of $600 - that includes speakers and if necessary some devices and cables. I would highly appreciate your help.
