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L-Acoustics KS21i

Install-specific high-power subwoofer featuring a single 21 in speaker with high excursion driver and optimized laminar vents to maximize LF efficiency - deployed in omnidirectional or cardioid patterns in stacked or flown configurations.
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Install-specific passive subwoofer with a high excursion, direct radiating 21 in transducer mounted in a bass-reflex tuned enclosure with laminar vents for increased LF efficiency. The enclosure cabinet is constructed of premium grade Baltic beech and birch plywood. The transducer front is protected by a coated steel grill and an acoustically transparent fabric. The enclosure integrates inserts for flush-fitting connecting plates and an optional acoustically transparent front screen. The four-point hardware allows for rigging and combining with other loudspeakers of the same family. Dedicated rigging accessories allow for flown or stacked configurations. Combining two or more elements with associated presets achieve omnidirectional or cardioid directivity patterns. Exclusively driven and protected by a proprietary amplified controller through a dedicated preset.


Max SPL 138 dB
Low frequency limit 29 Hz
Transducers LF: 1 x 21"
Weight 46 kg / 101 lb
Directivity standard or cardioid configurations