Preamp and subwoofers

I am adding a pair of subwoofers to my system.  What is the best way to the preamp outs? 

Just my opinion .. I run rca left and right preout to my input .. I do not need to roll off and send back i run my sub very low 40 hz down sometimes lower . Depends on your room, placement , spkrs eyc etc .. I use all acoustic zen cables personnally and love them . My two cents 🙏
 sorry zar .i misread the post. i would have acoustic zen make me a split y .Mr lee will rock it out at a reasonable price . what speaker do you have and room size ?