I'm currently using two 18in btln2 on an xs8k in a 05 Hyundai Tucson enclosure was design by ram. I demo often with my four doors open and it sound great but there's a problem with loading when my doors are open I loose the deep sounding bass that I love. I'm either going with a ported wall down the center or a 4th order band pass. I'm worried that with the port being so close to the door that I'll have the same problem with loading that's why in considering band pass. New sub will either be the team fi or dc lvl6. So my question is what sub and orientation would best suite me app? If any....lol!

I'd almost say sealed with a DUMBASS amount of cone area

Hello from Martinique ! How are you ?  Here in Martinique we have lots of Sahara sand in the air (like a perpetual fog) and tons on tons of Sargasses seaweed (it stinks like sulfur, like rotten eggs) on most beaches.

 

Back to your thread :

 

I would not do the DC subs ! You have BTLs : those are fantastic subs ! And you know that !

Try the Team Fi/AA/SSA !

 

I am afraid to see those subs in sealed sections for 4th order bandpass boxes : I think they don't really like that. But I'm not a specialist at all  

I can't tell you nothing on the box to use, sorry !

 

I have some local  friends who are a lot into demo cars : they use some kind of boxes that look like pro audio ones. They don't play low notes, but they're loud as f... I don't like that, but they do !