Can this be done with good results? I'm not picky I just need something that sounds better. I did have a 7400 Pioneer in my old truck but I traded that in for a 99 4WD EXT S-10 that has a factory headunit. So can I sucessfully hook up my coustic amp and mtx 10'' sub to my factory headunit? I also want to replace my 4x6 and 6 1/2 speakers.