The hd Infra218 is a high-performance subwoofer for reproducing frequencies below 28 Hz. Compact dimensions and exceptional power reserves combined with minimal distortion make the hd Infra218 a modern and flexible tool for touring and installation applications requiring extreme low-frequency sound pressure and maximum control over dispersion. The optimally tuned, horn-shaped multiplex enclosure with bass reflex tuning accommodates two special 18″N high-performance chassis with a linear stroke of 30 mm and a load capacity of 14.4 kW. A large, air flow-optimized center reflex port allows excellent air excitation with minimal turbulence and distortion. Thanks to its long throw range, high efficiency and passive directivity, the hd Infra218 can be optimally integrated into LineArray applications. Two M20 threads allow horizontal and vertical operation with distance rods. A Speakon turning socket in the protective grid allows cardioid configurations without an interchangeable cable.