Drummy-Q is a plugin specifically made for mixing drums. The easiest way I can think of to explain the concept is to just give an example of how to use it:
1. Set band “x 2” or “x 4” to full gain (+12dB)
2. Rotate the “Tune” knob until you hear a jump in volume as you near the drum’s resonant pitch
3. All EQ bands are now automatically set to multiples of the frequency you set on the “Tune” knob
4. Turn up or down the different bands and see how they interact with your drum. Set the Q’s according to taste
If you are still reading, I can give you a bit of this plugin’s background. I typically use a technique similar to this, with whatever EQ I am using. It can be a giant hassle, an enormous PITA and a big waste of time, when I decide that I probably got the original frequency wrong, and need to reset all the frequencies. This plugin was meant to fill a specific need and is certainly not for everyone. This is only the first of a series of toolbox style plugins that I intend to build, focusing on the very areas that always vex me while mixing.
PLEASE report any issues or problems on my forum or on the REAPER irc channel.