ISUB-18 is a self-powered professional sub woofer system. It employs bass management, hi pass filtered outputs, a sealed front firing 18" cone loudspeaker, and the INFRA dual integrator. This drives a 700watt power amplifier providing a flat acoustical response down to 8 Hertz. Six inputs allow the combining of all the bass information on 5.1 surround programs and 2 level controls and a 10dB attenuator provide relative adjustment of the bass information from the 5 full range channels and the dedicated low frequency effect channel.