Genesis APM-1 subwoofer substitute

This speaker is somewhat renowned for problems with the subwoofer amp but, even so, I am interested in purchasing a pair. Because it appears to be a major problem/expense to find someone to repair them I'm looking for an alternative approach to this repair challenge.

I'm not able to locate a manual so don't have a way to evaluate the circuitry and am wondering if it makes any sense to disconnect the subwoofer circuitry on both speakers and use a single stand alone sub powered directly from the stereo amplifier. Another alternative to this potentially ill conceived approach would be to use a powered sub to each speaker. The challenge here would be to somehow find a way to feed them using the crossover circuitry in the existing speakers.

Also, these speakers have what appears to to be a involved set of controls that probably rely on all of the circuitry to be in place. Again, though, the lack of access to manuals complicates the challenge.

This issue appears to be somewhat common and these speakers are worth spending time and effort on their repair so I'm hoping there is someone out there with some advice that would either help with a fix or keep me from getting in over my head.