Those are 2 FI BTL 15's fully loaded powered by 2 Orion 2500D's. 4 cubes each, tuned to 30 HZ. That's why there's so little port area. Just my street beater. Low's are amazing. The uppers are decent but lacking on alot of songs I like, but again the lows are amazing. I can feel things in songs I never knew were there. The vibrations in my back and gut are crazy. 2 9515s will fit easily. I have 2 Group 31 Blues and 2 Runs of Kicker 0 guage to the back. About to order 2 260 amp alternators from Dom.