There is another thread, a lot longer with more pictures, of a guy that did a speaker upgrade. I found it a very long time ago. You have to order carefully and the plastic mounts are delicate (remembering from reading the thread).
Ford used a variety of different speakers in the FFE. Can't tell you if you'll hate the speakers in your car or not. Live with them for a while before you decide to upgrade them.
I've had a 2012, a 2013, and a 2012 FFE (and we have a 2012 Focus Titanium with the upgraded sound system). In the FFE there was only one of the bunch that had really good speakers. The other two sounded bad. Given how they are manufactured (in random order with the ICE Focus), it is highly likely they have some mix ups with the speakers they throw in the car. The Focus Titanium has no need for an upgrade - then again that has a sub (or really a big bass module) in the rear. There isn't room to put that in the FFE.
2014 Platinum White FFE (Turning in mid Dec. 2016 25,000 miles)
2013 Ingot Silver FFE
2012 Titanium ICE Focus
2014 Tesla Model S 85