I'm a stereo guy. I'm a Mac guy.
I use an active OXO for the bass 300 hz <
Channel A is split and the subs and OXO are hooked there.
Channel B is for the monitors, they are, split and do active subs, also.
I have a line level out, non switched also. That's 3 pairs of stereo out.
Nothing in the signal path between my monitors either, they use a passive XO. The cut off are built into the onboard xo, ay...
Best of both worlds...
Why do you need a tape loop? You could also split the pre from the amp if you have a tap, and do it from there too..
I have plans for a ZPre3 in a tape loop on my C20. It will add all kinds of goodies, sub out volume control, REMOTE control, with volume control...
I like it..
Might be other ways too, someone will chime in.
Regards...