the above diagram is a bit misleading, as it does not refer to a monoblock with dual output connections.
if you look at option2, you'd see that the positive of one coil is connected to the amp's positive. the negative of that same coil is connected to the positive of the subs other coil. the remaining negative goes back to the amp. well thats what series connectionis all about. so essentially, with your dual outputs, you can connect one sub to each connection pair. of course, when you series the subs coil, the 2 dual 4 ohm coils will yield a 8 ohm. so you'd be connection an 8ohm load to each "output" so to speak. as mentioned before, the outputs are internally paralled, so, the amp sees, eventually, a 4 ohm load.
that amplifier is NOT 1 ohm stable, so DO NOT try option 1.
