door drivers are "woofers" only in a special "tuned port". There is a crossover (do not know what the cut-off is, sorry) built into factory amp.
In any event, doors are driven by amp combining the low level signals of front and rear channel inputs from head unit. Fade should be set in middle (even if no rear speakers) to get "most" out of them.
You'll understand all the " " when you replace them along w/ the dash speakers w/ something a bit more substantial, responsive, and w/ better range.
Good luck
