The 667 is a finicky animal. I've had 4 if them. 1 I had wouldnt squinch put more than 400 watts ( and it was new, I sent it back to texas star 3 times, and it never was right, so they just replaced it), 2 that ran right at about 550 PEP with a 2.5w drive swinging to about 30w, and one that was...