You have never experienced bass quite like the SR Series manifold subwoofers.

Built-to-order in the U.S., SR Series subwoofers provide powerful bass output that is visceral and exciting, but also shockingly tight and tuneful. Folks familiar with Theory’s smaller subwoofer transparent and textural sound, will immediately recognize the quality of the SR Series subwoofer low frequency reproduction.

The SR-221LF, the largest of Theory’s SR manifold subwoofers, houses two proprietary 21” 3,600W woofers with 4.5” voice coils in a large-but-clever enclosure that is surprisingly easy to transport via its optional caster kits and a smooth-as-butter universal dolly board.

Like all SR manifold subwoofers, the SR-221LF features 2 huge low turbulence ports, five 20mm “top hats” on three surfaces for full range speaker pole mounting, driver access for field service, no less than twelve horizontal and vertical handles, bottom and back panel anti-skid rubber feet that mount to M10 fly points (with pockets on the top surface to insure safe stacking).

Passive versions can be upgraded to powered versions with a Theory SR Series amplifier kit (sold separately).

Optional accessories include permanent and quick-release caster kits, and a thoughtfully designed universal dolly board that works with all SR manifold subwoofer models. The dolly board offers amp / input panel access when installed, horizontal and vertical handles, quick release latches, and a stackable design for easy storage.

SR Series manifold subwoofers are available in black and white, and in passive or active versions depending on the installation need. Upgrades include custom paint matching and weatherizing (of the passive version only).

Capable of astonishing output combined with high-fidelity sound, the SR-221LF will have you rethinking how you design your next portable or installed sound reinforcement project.