The ES1.8 is a high-output, reflex horn loaded, single 18" subwoofer, designed as a part of the ES Series sound reinforcement system. It provides tight, up front, low frequency extension with authority, attack and definition. Designed to be used in pairs, or with up to two ES1.5, the ES1.8 can achieve high output levels consistently and safely. Alongside the ES1.0 and EPAK2500/R, ES1.8 offers a very firm foundation on which to build a powerful ES system.