Hey, hows it going.

I recently obtained a fairly old Realistic MP-80 amplifier (mono, 80W, 4 ohm) and i want to install it into sound system. i basically want to use it to power a Optimus Pro SW-12 subwoofer (150W, 8 ohm) (itll be massively underpowered, i know, but anything is better than the 10 watts im running it on now). The problem i have though, is that the optimus sub has 2 sets of spring clip terminals as the input, instead of just one set. and my amp is only mono, so therefore i can only use one of the two inputs on the sub. i hope you can visualise what i am saying.
i dont know how to combat this situation. i am thinking that because the sub also has two outputs, wiring up only one input, (if that would work), would result in only being able to use one output. that is ok, cos i have 2 Teac 2 way mids i want to use as well and i can wire them in series or parallel.

it would be greatly appreciated if anyone could give me some advice or help, about anything i have described. thank you.