I'm trying and trying simulation for sound reinforcement sub-woofer enclosure. I do several simulation with a promising driver (18 inchs), but I cannot decide in between a usual bass-reflex (about 120 Litres), or a 6th order band-pass speaker, with almost the same size. In theory, I got nearly 3dB more on the 50 to 100 Hz range (the range I'm interreset about) with the band pass, but is that reallity ? what about the sound ?? does it sound like a drum, or like a real speaker ?? I mean, does it have the bad habits of shiffting the frequency near its hown resonance frequency ?? (I hear this on some PA system, and I really don't want something like this, sound like every bass notes are the really same)