Well, they got installed today. They are on a JL 450/4 and I got kicker resolutions in the rear. Well the sound on boston acoustics are nice, but not what I expected for the upgrade and money. I had kicker resolutions before, but 1 of the woofers popped, so I decided to go all out on new stuff. Well I thought these z6's would be really really loud and not distort? I still have the kicker tweeters in the mach 460 panels and the z6's are together in the door with tweeter on top. The installer said these are so loud your crazy. I dont know maybe I expected way too much. There loud but they dont hurt my ears lol. I have a 00 mustang convertible. Its kind of hard to get nice sound in it. I still can kind of hear a little distortion when I really crank it up and I want it louder and crisp and clean. I guess no speaker can really get so loud! and clean sound. I dont know, maybe Im crazy. btw I also have a 13w7 on a JL 1000/1. Also I hear a engine whine now sometimes when the volume is really low since I cant hear lyrics. I hear the engine whine in the speakers when revved. Is the 4 channel amp a bad ground? Is it the radio ground? I have a clarion indash.