Sorry about that.

No worries - it happens to all of us sometime.

But still, why would you not want to filter the frequencies less than 15 Hz when my sub is only rated to 18Hz, though in a sealed (I typed ported again) box? From what I've read, that is a waste of power.

Well, if your sub can't reproduce below 18Hz, then yes do set the SSF to 15Hz, no harm in that. OTOH, unless you play stuff like Bass Mechanic tracks or test tracks there probably isn't very much content below 15Hz in "ordinary" music, so I don't think you'll waste much power in reality.

/Michael