The TS221 is a portable, dual 21 inch, direct radiating subwoofer designed to provide gut churning impact and solid musicality – not just infrasonic effects. Its 6 inch voice coils, unusually rigid cones, and innovative low-turbulence ports permit an optimal tuning to be achieved in an enclosure that is light in weight and truck-pack friendly. Eight handles and an optional face pallet facilitate transport of the enclosure. An M20-threaded connector plate is centered on the TS221’s top panel for use with the optional, height-adjustable SP1 Speaker Pole. This pole’s M20 threaded bolt screws securely into the connector plate and is used to mount loudspeakers equipped with a 35 mm / 1.38 inch pole socket directly above the TS221. Eight vibration isolation feet prevent spurious vibrations and “walking”. When stacking enclosures, the vibration isolators nest in recesses in the enclosure below. The recesses are configured so that enclosures can be rotated to create cardioid arrays. The input is mounted on a chamfer at the rear of the enclosure, allowing cable access without requiring additional space between the enclosure and a wall or stage. The TS221 is perfectly suited for highly dynamic touring systems, live performance venues, and nightclubs. Its massive output capability matches that of two to three conventional dual 18 inch subwoofers, reducing transport costs and saving precious truck space and venue real estate. An optional rigging kit allows up to twelve TS221s to be suspended with a 10:1 design factor.