Audio Systems: upgrading 99 explorer Mach Audio System, watts rms, rms

Question
I like the sound of this system, but it's not very loud. I'm thinking of having some boxed subs installed and am wandering if it is possible to replace the amplifiers powering the speakers and sub with more powerful ones? Will the door speakers handle much more power? I haven't been able to find any wattage specs for this system.

Answer
yes it is posible you need a hi/low interface
the door speakers are 5x7 and hold about 20 watts
the rear 6 or 8 inch wofer hold about 30 watts if you replace with aftermarquet you only get 15 watts from the woofer

your fatory ford amplifier is only 7 watts rms x 4 channels