Hey, @aball. My experience, FWIW, is to match your woofer to your subs. The amps driving a lot of modern subs are "plate amps" so the fact that you are using a McI model X almost doesn’t matter if the feed is high level or line level. The trick for my system was not to get any crossover in the way of the main speaker- which goes directly from Lamm SET to horn w/out crossover (mid-horn). That then jumps to a tweeter (horn) and small (2 x 10 inch) woofer array. The latter doesn’t play loud or do deep bass (two different things without sounding discontinuous with the mids). So the main system plays and the subs are first DSP’d to the room (saves a lot of trouble despite bass traps, etc.), then down-tuned to a 55hz roll off that is steep 24/db/octave. The phase adjustment is continuous so I tuned them so a double bass sounds like one. I’m happy, it’s not a lot of money and it gives a sort of "spacious" sound even to material that isn’t necessarily bass-centric.
