It's the right impedance and everything. Obviously, the blue boxes are the actual boxes in which each sub is contained. The wiring inside each box is completed correctly.
However I'm confused as to how I would "split" or whatever I have to do with the section of wire denoted by the green circle. Do I split that wire? If so, how? I've got butt splices if needed, however is I have to solder, I don't have a solderer.
I would solder it and then put heat shrink on it I think this is the best way. Now that being said, you can just twist them together then take some pliers and twist more.Put tape on that good. You should have no problems.
I sugest you go by radio shack and purchase a soddering gun. A decent one is about 15 bucks. While you are there pick up a role of sodder, and some shrink tube. Price for all 3 would be about 25 bucks. Sodder and shrink tube is by far the best way to go. The second best would be to use a crimp connector. Do not just twist the wires together and tape it. That always leads to problems in the end.