UPDATE ...
As it turns out, both the xover and the phase needed to be re-set once I switched to using the sub's line out. I set the xover to 80Hz and phase to 40 degrees. Now, it sounds really awesome. Much greater headroom for the highs and mids, and the e110 really digs down deep without any bloat. Those things, coupled with my having put in a set of new tweeters, is really making me love this new sound.
As it turns out, both the xover and the phase needed to be re-set once I switched to using the sub's line out. I set the xover to 80Hz and phase to 40 degrees. Now, it sounds really awesome. Much greater headroom for the highs and mids, and the e110 really digs down deep without any bloat. Those things, coupled with my having put in a set of new tweeters, is really making me love this new sound.