Quote originally posted by Parasitic_Whim
It doesn't matter what way you face them, in or out, the box will sound the same . . . like crap. Bandpass is a gimmick. If you want big output, go ported, it will still sound a hell of a lot better than bandpass (and if you're really good at designing them, even sound better than sealed)
I would have to say, we have designed and built some pretty damn impressive bandpass enclosures back in the day. They are not the easiest to get right but when they are right, the work well. For big, thick bass though, I do prefer a simple ported design.
Here's the largest (and loudest) bandpass we've built. I believe it was metered low to mid 150's if I recall, but that was many years ago. Not loud by today's standards, but holy crap this thing would make you sick if you sat in there too long. I haven't been into big audio like this for quite some time now.

Laying on the roof

Inside the bandpass - MTX Black Gold

The boxes on the doors

The boxes on the doors

GMC Jimmy Bandpass Install

Driver Selection

Driver Selection

DD 9512
Wow this brings back memories.