Drum sound sample

[charger]

I'm getting to be pretty happy with my drum sound... just wondering what people think I can improve on without spending too much money.

(Don't be afraid of the fact that these are wav files, they're short loops, only about 5 MB total.)

http://www.chargermusic.com/drumloops/rocking.wav
http://www.chargermusic.com/drumloops/rocking2.wav
http://www.chargermusic.com/drumloops/rocking3.wav
http://www.chargermusic.com/drumloops/rocking4.wav