high level inpits

Hi, I've just upgraded my sub, it's a hertz mps 250 s2, I need to change the settings on my audison sr 5.600 so that the sub is getting the full 550 watts, at the moment it's wired up using the rca inputs, on the instructions it has 2 configurations for five channels. 75w x4 +330w x1 at 4 ohms...