Until I put my hands back on an SPL meter and fine tuned the calibration of my EP-500, I was frequently toying by those settings when playing music. But since I got the merge perfect, I don't touch the 80hz cross-over.
Cello and organ (to name only two) can play as low as they can (even glissendi of contemporary music) and I cannot hear a transition (and my sub in behind my couch). So, my two cents are, if you have a musical-enough sub (I don't know your brand), just make sure you use a calibration disk (ex: Avia) to verify/set that the blend of the transition from all your speakers with the sub is as seamless as possible and you'll be home free.
