I never said I run my mains in large either. I run them in small, 80 Hz XO in the receiver, 150Hz XO in the sub.
And, I never said turning the subs off in this configuration would result in decreased bass (of course it would). I said turning the subs off and setting the mains for full range (i.e., the mains play it all. Receiver set for no sub) resulted in a very apparent loss of bass.