how are u wasting potential by not using a SSF? all it does is retrict it from overextending on really low notes that only bass test songs go low enough to do any damge . a SSF is not needed if u tune low, like 30-32hz and dont listen to bass testing songs.Yes, they are needed. Below the tuning frequency, the box loses it's reflexive quality and the sub begins to excurd tons without great output. Yes, you can run a ported box without one, but you really should be running one, otherwise you are wasting potential.
Graph the excursion in WinISD and tell me you dont need a SSF in a ported box.