I have Diamond Audio hex series 4" components with the hex series midbass add on running a passive 3 way setup. the midbass are in the doors and the 4" mids and 1" aluminum tweeters are in the kick panels. I was dissappointed with them not getting loud enough and honestly I dont think they sound all that well. I had a set of CDT HD series and I think I shouldve kept them. stay away from the hex series. I dont know about there top of the line series the D9 but Ive heard good things about those but thats what I heard about the hex. Just my personal opinion