OP
My current box is built to Infinity's specs.
What is the real point in Bandpass, I have heard that they can sound great but for the extra money and design issues do they really offer that much more in any area. In other words how does a well designed bandpass compare to a well designed ported box tuned low?Check out http://www.decware.com. They are under the Speaker tab to the left of the page after you enter.
The ones you would wanna look at would be the DeathBox 2 and the Wicked One.
I had never really heard of them until I stumbled upon them building a setup for my new car a few years ago- but those two designs are amazing output. Especially the Wicked One. SQL Monster.