I choose Bandpass/Bass Reflex because they seem to have a more natural sound, IMO. With their design, there's no need for a low pass filter. The Highs are filtered out naturally. But, some still do have a low pass filter. I gotta Band Pass passive subwoofer hooked up to my Pro Logic surround system and it sounds pretty good. Another advantage of band pass is that it'll hide any distortions the speakers might get.