loudest??? u mean a verage loudness or specific loudness????
average loudness can be bandpass and sealed... ported will be specific since u can tune it to an specific frequensy to make that specific tuning louder... sometimes bandpass are alot louder than ported but are hard to design but u cant never say wich one its louder.... since there are subs that can be louder in a sealed than in a ported subs it depends on the sub car power etc...
but most of the time yes its ported... if u know how to do it right
bandpass if properly built will peak at only a certain hz and then hit no other note so its a one hit wonder if built properly will demolish all but for noobs ported man
t lines and horns are VERY efficient. much more so than ported and better sq than ported or acoustic suspension. bandpass can also be used for insane spl and sq
loudest would equate to the most efficient, which is going to be a 6th order bandpass usually.. they sound like crap, one note wonders.. and extremely difficult to build properly. If you mess up on the calculations, you blow the cones out of the subs the moment you power up the box, but when they work, they have some tremendous gain.
