[daeron80]

Shifting the formant of some overdubs, some up, some down a little (no more than 3 semitones) may help, if it's mostly one person overdubbing himself. Then again, I think those monster group vocs on old Def Leppard records are all one guy, and they didn't have formant shift back then! That was done locking two 24 track analog machines together, bouncing huge numbers of vocs down to stereo, and adding more. Insane.