The IL 115 Sub is a very compact subwoofer, which extends the frequency response of the loudspeakers IL 8.1, IL 12.2 and IL 15.2 in the bass range. It is equipped with a direct loaded 15''-cone loudspeaker in a bass reflex housing and has a built-in passive crossover. The IL 115 Sub stands out through its powerful, low-distortion and thus natural bass reproduction with compact dimensions. It is ideally suitable for acoustic applications in which the bass range of existing loudspeaker systems should be extended for distances of up to 20 m depending on sound pressure requirements. A controller is not required for operating the IL 115 Sub. It is possible, however to use the Digital Field Controller (DFC).