While Johnnyb53 has had experience integrating subs in more systems than I have, his experience parallels mine. With both Magnepan 1.6's, my ACI Talismans with integrated powered subs, and my current Tidal Piano Cera's, it wasn't any big effort to get excellent results with a half hours set up time for the subs. Sure, I listened and tweaked as time went by, but it is a fun and enlightening process to refine your listening and set up skills IMO. There a bit of variability among we audiophile's as far as our propensity for hand wringing, neurotic obsessing, and exaggerating difficulties in these matters, so take this into account in your considerations. The newest generation of subs from Velodyne, JL Audio, etc. have programs to help speed up the installation process and have corrective software for the worst room response anomalies.
REL G2 or JL Audio F112 ..thoughts for 2 channel
I have a pair of Sonus Faber Cremona M's floor standing speakers.....they go down to 40 hertz.......I was thinking about adding a sub in a room that is about 11' across and 20' deep with a 7' celing.....the speakers are on the short wall. The room is all ASC treated. I do not have all that much room on the side or in back due to Purist Audio cabeling......but it could be worked out. I have heard that the REL G2's would go well and yes I know they are both owned by Sumiko.....your thoughts