Ok here's the deal. I have two 12's (I think their Rockford Fostgate they say punch on the front) and want to put them in my 92 wrangler. I know I need to build a down firing box but don't know how. I also don't know what size amp I need. My friend had two 10's in his car with a 650w amp and it sounded alright, so I was thinking 800w for 12's. I don't want you to be able to hear me two miles away I just want to hear my radio on the interstate.