i currently have a 12" db 500 tuned to 18HZ being bushed by an ED LT/350. this setup sounds great but i want more. i was thinking of going to a 15" driver and maybe doing a sonotube. what would be a good driver to pair with the behringer ep1500 for a room that is about 12x18x8. also what else would i have to get to make the ep1500 work or will the sub cable from my receiver plug right into it just like the plate amp?