Power-Packed L-Acoustics KS21i 21-Inch Compact Subwoofer
Upgrade your audio experience with the KS21i! This compact subwoofer is a game-changer for installation setups. It pairs seamlessly with A15i and A10i systems to enhance your sound. Here's why you'll love it:
- • Extended Bandwidth: Take your low frequencies to new depths with the KS21i's ability to extend the bandwidth of A15i and A10i systems, reaching down to 29 Hz and 31 Hz respectively.
- • Reduced Turbulence: Enjoy a smoother audio experience with L-Vents that significantly cut down on turbulence and port noise, even at high volumes.
- • Versatile Configurations: Whether you need a standard or cardioid setup, the KS21i has you covered with dedicated presets for both flown and stacked deployments.
Specifications:
- Description: High power compact subwoofer: 1 ¡Á 21' amplified by LA2Xi2 / LA4X / LA8 / LA12X
- Low frequency limit (-10 dB): 29 Hz ((KS21_60))
- Maximum SPL: 138 dB ((KS21_100))
- Nominal directivity: Standard or cardioid configurations
- Transducers: 1 ¡Á 21' neodymium cone driver
- Acoustical load: Bass-reflex, L-Vents
- Nominal impedance: 8 Ω
- Connectors:
- 4-point terminal block with push-in connection
- Connector sealing plate with cable gland
- Rigging and handling:
- external rigging kits
- M6 inserts for rigging plates and accessories
- M8 inserts for A-U15i
- Safety: 1 DIN580-compatible M8 threaded insert
- Weight (net): 46 kg / 101 lb
- Cabinet: Premium grade Baltic beech and birch plywood
- Front:
- Coated steel grill
- Acoustically neutral 3D fabric
- Rigging components: High grade steel with anti-corrosion coating
- Finish:
- Dark grey brown Pantone 426 C
- Pure white RAL 9010
- Custom RAL code on special order
- IP: IP55


The L-Acoustics KS21i is a high-power compact subwoofer designed for installation applications. It's perfect for venues like theaters, clubs, and auditoriums where high-quality audio is crucial. The target users are audio professionals and installers seeking to enhance their sound systems. With a 21-inch size and a net weight of 46 kg (101 lb), it's easy to handle and install. It features one high excursion, direct-radiating 21'' transducer mounted in a bass-reflex tuned enclosure. The subwoofer couples with A15i and A10i systems to reinforce contour and extend bandwidth. It has L-Vents that reduce turbulence and port noise, increasing LF efficiency. The frequency response is optimized to pair perfectly with A Series install systems. It can be flown and stacked with A15i or A10i to form a full range line source and can be deployed in standard or cardioid configurations with dedicated presets.