Innersound Eros owners

I've recently replaced my panels with the  Sanders new panels. They are wonderful sounding speakers, but I have
these 2 Velodyne F1200 12" subs sitting around doing nothing. Has anyone tried subs with these? Also how are you hooking them up,line level or speaker level, whats the best way? I figure it would also help with power as the subs are powered. And what crossover point? I'm currently powering the panels with McIntosh MC501's with the original Eros bass amp and a Mac C2200 tube Preamp.

 Thanks