Muscle, I do not mean to be rude here at all, but....

However had your car before you clearly bastardized it quite a bit, between the stereo wiring and the door pulls alone. If I were you, I would connect the speaker right at the back of the head unit to test it. If you are getting good sound here, it is your wiring or speaker. Since you have already replaced the speaker (2x) I would say it is probably wiring. Good luck.