i have audiobahn alum12x subs as well as someone else on here but i forget. I am very please with the way they handle and sound, i also have 3.5 audiobahns, also very pleased. you will not be disappointed with audiobahn products.
My friend had two 12" in a bandpass box type of setup. They make a lot of noise (notice I said noise) but the quality of the sound isn't the greatest. If it's just noise you want, these would work out great, especially for 2 of them. But if it's quality, they didn't sound too good IMO.