a well built ported box will sound equally as good as a sealed (louder and deeper too)
if you have the time to design a very good bandpass box then go for it. don't buy prefab bandpass box like the ones at best buy. anyone that has dealt with rmscaraudio.com will tell you that the single 10" in a bandpass has hit harder than many single 15" out there. not to mention the accuracy of their subs are like that of a sealed box
