Well the stock speakers in a Crossfire are already Infinity. Did you buy Infinity Kappa speakers ? The door speakers are 6 1/2 inch with a 1 inch tweeter mounted higher in the door. There is a 6 1/2 in sub behind each seat. (not sure if the base model has subs) The factory amp is in the pass side floor pan. Some folks find that installing a cap on the door speakers helps. (https://www.crossfireforum.org/forum...gest+bang+buck )
I think it would help you as well, It keeps the low bass notes out of the small door speakers. Return the speakers you bought. You want to listen to your music LOUD with a LOT of BASS, Right ? (I know because I like it that way too). What you need is a sub woofer and a box to put it in. An amp to drive the sub. At least an 8 ga wiring kit for the amp, Don't forget the fuse. Latter get a new head unit for more control, Adding an Ipod etc. Do some searching on this forum about stereos and check out http://www.crutchfield.com/ Enter this code Your Crutchfield Referral Code: pr26q-6cux3-tk78c and save $20. I saw this box on Ebay http://cgi.ebay.com/Chrysler-Crossfi...QQcmdZViewItem
it looks good but I don't really know. You may find out more by searching the forum. Btw, Crutchfield will say to need to run all new wires to change the head unit but you don't have to do that. The Crossfire only has speaker level output on the stock head unit so there are only speaker level wires there. If you need rca cables you will have to run them yourself. It's all easy to do, Just read up on things before you start and then take your time. This will show you how to get at the wires, speakers, etc. https://www.crossfireforum.org/forum...ad.php?t=13875 get the service manual.