I have 5.25's in front i didn't use the adapter i just got the speaker in there by one screw lol its been fine so far. i blew out my subs the other day i can't afford to replace them nor do i want to so i'm just gonna do the 6 1/2 and the 2 6x9's in the back and that should be enough, if not i might consider getting a console out of a 2001+ wrangler with the sub in and go that route