HI everyone, I have been looking into upgrading my audio in my truck and I have a couple questions. It seems like the cheapest way to get a clean signal is using the forscan method. Iv done some research but still have a few questions. I found this thread http://www.2gfusions.net/showthread.php?tid=3704 and noticed that he enables line level with optional sub/ front center enabled. What does that mean and is it ncessary to do? Can i just get by with where he disables eq processing? If i do those both does that shut down my factory amp making my door speakers useless until I add an aftermarket amp to run wires straight to the speakers from the aftermarket amp? One more question, if i go the route of the pac amp pro does that also make the door speakers not work? What i mean by that is can i plug up the pac amp pro and only use it to wire in my sub amp but still have the front and rear rcas available for when I'm ready to run amps for my door speakers. Sorry if I didn't make much sense on some of the questions I am trying to ask. Thank you all for the help!