I have a 2012 Limited with the Sony 12 speaker system. It's a fine sounding factory system, but I am a bit of an audiophile. I don't purchase commercial speakers for my living room, office, or home theater, instead I build from the ground up (cabinets, crossovers, selecting the best drivers). I'm not as picky when it comes to car audio since the inside of a car isn't idea for hi-fi listening, but I would still like to make the most out of what's available. This morning I started down a journey to upgrade the audio system. First step, was to simply upgrade the subwoofer since it is VERY muddy. I had a few drivers laying around from previous projects and testing so I thought I'd see what I could do. Following will be the steps that I took. These steps may differ based on the trim package, audio package, and other options you have in your Explorer.