connecting

Hello everyone. I have silly question - haw can I connect WCA411 to ProFet5.1? Because I have one output on Profet, and two inputs on WCA. And tell me if I'm correct, I can use jacks or SpeakOns?

So I want to connect two basses in the same power amp but there are two problems: 1) I have only one pre-amp ( Line 6 Bass Pod) and I need one more. I'd like it to be as simple as possible, so as not to change my bass'es sound. 2)There is only one input on the power amp so how can I connect...