Inconsistent Clank

I don't think I have to define what I mean by "clank", you guys surely know what I'm talking about. My problem is that the E string clanks and sounds fine, but the D and G strings and anything higher than the 5th (ish) fret on the A string just won't clank. It's not that the strings aren't hitting the fretboard...they are. I have the attack down but for some reason my strings refuse to produce clank. I don't know how to explain it but that's the best I can. The strings are relatively new so they are not dead. Anyone have any explanations for the lack of brightness?