That may be tricky to isolate the crash enough to adjust the volume only on that segment. It may or may not affect something else on the drum track, depending on how complex it is.

If you can isolate it well enough, you might try to magnify that section and highlight the wave form where the cymbal crashes then do a slight gain change. You might want to try smaller decible changes one at a time until you have something that you are happy with.

If the track is too complex, it will affect more than just the crash.

Dang....This is addicting.

http://www.reverbnation.com/roberttrippmusic