I've searched high and low, and I can't seem to find a frequency agile compressor with a side chain function... I often use side chain comp on guitars to duck them a bit when the vox come in, and I want to experiment with whether this might be more transparent if I were just compressing the frequency ranges of the guiat most heavily occupied by the vocals... I can make it transparent now, but basically I'm wondering if I can squeeze a few more dB of ducking out of the guitars if it was just the high-mids being comp'd for example. If anyone happens to know of a plugin that would have that feature I'd very much appreciate it. The other way I could try to do this is with trickery... If I'm tracking guitars with SM57+MD421, maybe only applying the sidechain comp to the 57 might work better, since that's the mic that's more mid-heavy. Or, when I'm reamping the guitars I could have 1 of the layers be a more mid-heavy sound, and only sidechaincomp that track... Sorry, thinking out loud here!