It’s easy to forget that the cymbals and hi-hats are actually two separate instruments. If they are being played together in a frenzy, their ringing can obscure one another and affect the overall balance of the mix. In order to get a more accurate frequency balance, it is helpful to isolate each instrument and adjust their volume separately.
Mitre 10 has several products designed specifically for mixing audio such as EQ Curves, Volume Envelopes and Compressor/Limiters. With these tools you can control how much each instrument contributes to the overall sonic coloration of your track.