I have the factory stereo with a Pioneer head unit and looks like pioneer door speakers all done by the previous owner. But it just sounds so bad. Mostly like there is VERY little volume coming from the front speakers or like it is cutting some frequency. I know there is a factory amp. Does it have a cross over or anything that would prevent all the frequency to going to the door speakers? I see that there are basically 8 speakers, ash, front doors, back doors and back head liner. In my mind that makes a 8 channels. I would imagine that the (after market) head unit has 4 channels coming out and going to the amp. Then the amp has 8 channels coming out Is this right? I dont really rcare to have a great stereo, just something to listen to. If it matters the rear sub was unplugged so i puled it all out.