Car wiring diagrams: Ford Expedition Subwoofer Replacement, wiring diagram, wire wiring harness, schematic circuit diagram, wiring diagran, wireing diagram, wirring diagram, wiring daigram, wiring diagrams. Dealer wants bucks for the speaker, enclosure and amp. Not familiar with the Mach system, but would think that if you can find a sub to match the mounting hole, it would work. Mach system is just the ford system with the subwoofer upgrade it s an " sub powered by it s own .Here is all you need to know to be prepared for the job of replacing your factory How to .What fits your Expedition? Tell us more about your Ford to see stereos, speakers, and subwoofers that fit..Putting this here for someone who may search the forum like I did. My new to me with the Mach sound system had a crackle at high .