The loose plug was the culprit here. Where is your bass setting? At max you will get pops on some music.
Solved that problem but my help had to work late and I had to setup alone Played dj for 30 min Waited till the last minute to do mic checks. No 1 & 2 mics Had to pull the inserts going to the 266xl Found out today the power transformer is bad (open primary) Now Ill see how good DBX tech support is and if they will sell me one.
My host didnt know what compressors do till he was adjusting mic levels last night.