The Atlas A-Line EJW115XI-W is a single 15" passive subwoofer in an optimally designed and constructed sealed Baltic birch enclosure. This design provides even sound distribution. The EJW115XI-W is designed to be used with an EJ2003-W full range line array system. The EJW115X-W needs to be used as a part of a pair of ELIJAH systems where an EJW115AI-W can be used to provide power to the EJW115XI-W and two EJ2003I-W units.