hybrid system sub integration

Hello !

I want to add pair of subwoofers to my existing system

I'm a little confused since my system is hybrid. I use passive XLR preamp to switch between my stereo source and HT processor. I do realize that the only way  to integrate subs with my stereo system is high level input on subwoofer . I'm just not sure about HT and sub connection . Subwoofer has both high and low inputs. Should i connect HT to sub via low level RCA ( in that case both high and low inputs will be used ) or just leave high level for both systems  and set the  speakers to full range in HT processor ?

I would preffer to use low level with  HT and let processor do all crossovers, and high level  with stereo.

Is it possible ?

BTW. the subs i want to add are JL Audio e110

Thanks!