I find if I'm playing faster riffs - say Hysteria by Muse - I sometimes find that I hear a clunking, metallic sound as I fret. That is, the string hitting the fret. So if I fret at the 7th and then play open repeatedly, I hear the sound of the string hitting the metal bar of the fret.
It's not that I'm fretting on the actual fret, but more the speed of the changes means that I get the metallic sound on string-on-fret.
How can I avoid this, bar learning to play fretless? (Which I really want to do, if I could afford another bass)