Dear God does do bandpass box's ****.
I have a Q-Logic dual 12" bandpass box with the subs slanted toward the middle, quite possibly the most expensive bandpass box made.
That **** will make your insides shoot out of your body it's so loud, but it can only hit like a 10 hz range (~75-85) around there. It hits the one frequency you turn your ports to.
I have 2x 12" Kenwood Tornados (blue, small inclosure, $139 a peice version, dicontinued I believe) 800 watt (250 RMS), and I will get a seal box when I get payed Friday.
I have a Rockford Fosgate Punch 500.2 and I have to turn the gain on full just to have adaquate bass at the right volume for the rest of my speakers ('cause I have an 1996 model panisonic cd player which only has one preout, I will replace it with a nice Alpine one), because bandpass box's need so much power.
Those subs I have and the bandpass box are quite possible the WORSE possible sub/encloser combo you can have, but before I get my custom .80 cubic ft / per side seal box, should I take off the plexi glass on my bandpass box so I get more than one bass note, or will the free air like enviroment hurt my subs more than that boomy sorry *** SQ all SPL box?