Subwoofer for 2 channel preamp

How can you hook up Power Subwoofer to 2 channel Preamp without Subwoofer output? I am using 2 of Von Schweikert Audio VRS1 Sub with Sim Audio Moon P-5 Preamplifier. Thanks for input.
Since your pre-amp doesnt' have a cross-over for a sub, you are going to have to use the ones in the subs. Feed the output from your left channel to one sub and then an interconnect from the high pass on your sub to your left channel on your amp. Do the same thing for the right side.
Buy two rca single male to two female adapter plugs(these are solid one piece gold platad, not y adapters).Plug the males into your preamp outs then connect your amp cables
and cables to sub line level in and use the subs crossover.
Thanks for your respond
I want to achieve the same thing too, but my component has a pre-out not a sub-out. Would I proceed the same way as suggested above?