This is an actively driven 2-way bass-reflex design housing three long excursion neodymium 18″ drivers, two drivers facing to the front and one driver to the rear. The cardioid dispersion pattern resulting from this approach avoids unwanted energy behind the system, which greatly reduces the reverberant field at low frequencies and provides the greatest accuracy of low frequency reproduction.

J-SUB cabinets can be used to supplement J8 and J12 loudspeakers in various combinations, ground stacked or flown, either integrated on top of a J8/J12 array or as a separate column. The cabinet is constructed from marine plywood and has an impact- and weather-protected PCP (Polyurea Cabinet Protection) finish. The front and rear of the loudspeaker cabinet are protected by a rigid metal grill and the side panels incorporate eight handles. Four 100 mm wheels and one EP5 or NL8 connector are mounted at the rear.

The J-SUB can be driven only by the d&b D12 dual-channel amplifier configured for it. More detailed information on specific loudspeaker setups with the D12 amplifier is available either in the relevant loudspeaker or D12 manual.