can I use the two main outs on a desk?

I have two active 15'' subs that can only be linked up to passive tops, my prob is I have two 12'' active tops on the way and the manufacturer tells me they cant be linked together, so Im thinking can i use the 2 xlr's from the main out on the desk for the tops and use the two 1/4'' main out for the bins, will it fry my desk?