The sound card should be "ok". The mic may be the problem.
I have a soundblaster Live value , and a soundblaster live 5.1 , on another computer . The mic I use is a cheapie Jensen ( 10 $ ) mic, and from what other counterstrike players have told me, my voice sounds pretty good.
I recommend upgrading your sound card anyways , not just or the mic , but it'll improve your gaming as well. I believe the sound card makes more of a diff than the microphone does , soundblaster 1024 value is sort of the bottom end of the soundblaster series...