I just sold my BL 12", was in expedition in about 2.5 cubes tuned to 32hz with a sundown 1500d. Sounded awesome, but i still want to get 2 BL 18's in the future. Now i am building new box for 2 FI SSD 18's to run off 1 sundown 1500d. Will upgrade probably next year to bl's and a 3000d. Box is going to be 16 cubes after sub and port tuned to 33hz. Anybody running ssd 18's? Kinda curious as how much louder it will be? thanks