Dioxide-
i don't want to come off sounding like a dick but the bands that you gave examples of have no clarity and no definition in the live setting. Ive seen every band you listed (except meshugga, and they are the only ones i like out of that list). Slipknot live was just one large wall of detuned noise when they played. Sloppy detuned noise, not anywhere close to what little definition they have on their albums in my opinion. Coal chamber's guitarist has the same problem, he might as well be playing bass through a distorted guitar amp. Korn's sound when i saw them live had alot more clarity than slipknot or coal chamber but when you play as slow as them and you only ride the top 3 strings CHUg..... chug.....chug ....bend a high note lol I can't see how it would be hard to get it to sound clean.
As i said before I love Meshugga but ive never had the pleasure of seeing them live. Somehow or another though, i bet those 8 string guitars are a bitch to get clarity in a live setting.
So whats my advice? If your taking cues from this "nu" school of metal EQ wise, start by putting some mids in your sound. It will help you cut through the mix and give you alot more clarity. Also roll off a good bit of the bass, it may sound weird to hear it this way by itself but youve got to remember your only 1 part of the mix, when everything comes together it will sound alot cleaner.