This answers the question I had in the back of my mind. A four ohm driver with a 200W nominal power handling seemed like not an ideal match for the powered Kempers, which put out triple that at eight ohms (let alone four ohms!). I do understand the concept behind clean headroom and "overpowering" your speakers to ensure clean power always, but it seems like a recipe for problems to have that much power available with a speaker that can only safely handle a fraction of it. I wonder how many people will not be careful and wind up blowing these speakers...
Well, we all know that "safely handle" and "be careful" are the foundations of rock 'n roll