The TFS-900H line array subwoofer comprises a total of eleven custom designed drive units, three high frequency compression drivers loaded by a Dendritic waveguide, two 6.5" high-mid drivers loaded by a Dendritic waveguide, four horn-loaded 6.5" low-mid frequency drivers, and two horn-loaded 12" low frequency drivers that utilise both front and rear cone radiation for maximum efficiency. The rigging hardware is fully integrated into the end-cheeks on each side of the TFS-900H cabinet, which also provide grab handle positions. Drop links at the front and rear of the box engage in the flygear of the above above in the array to give a range of inter-cabinet angles from 0° to 5°. TFS-900H cabinets are normally transported four-up on the TFS-DOLLY wheel dolly and can be flown right off the dolly in blocks of four, with the rigging hardware already pre-configured for use. A simple TFS-GRID and TFS-TIP system is used to fly a typical array; no additional external parts are required to fly the system. Driver maintenance can be performed without removing cabinets from the dolly as all the drivers can be accessed either from the front (the entire mid/high section is removable) or from the rear via the driver access doors. Amplification is provided in the form of the highly advanced and extremely powerful 20000DP four-channel amplifier with Lake processing and Dante networking built in. The power capability of the TFS-900H's four frequency bands exactly matches the output of the 20000DP's four output channels, with only four racks of three amplifiers required to deliver optimum energy transfer into a system of 18 TFS-900H tops and 12 TFS-900B subs. The TFS-900H cabinet is constructed from 15mm birch plywood and finished in black TourTough finish with IP54 rated stainless steel perforated grilles. A recessed rear panel carries two parallel-linked Speakon NL8 connectors for input and loop-through connections.