Overview:
The KS21 is a compact, high-output subwoofer designed to perfectly complement the A15 series. With exceptional low-frequency performance down to 29 Hz, it delivers powerful, controlled bass in a small, road-ready footprint — making it ideal for mobile productions, touring, and dry hire setups.
 
Key Highlights:
 
Deep, Defined Bass: Delivers a powerful SPL of 138 dB with a tight and responsive low end down to 29 Hz — perfect for enhancing live music and impactful playback.
Optimised for A Series: Designed to integrate seamlessly with A15 Focus and A15 Wide in vertical or ground-stacked arrays.
Slim, Touring-Friendly Build: The front-ported design fits 2 × KS21 subs side-by-side beneath an A15 array, saving space on stage and in the truck.
L-Vents for Clean Output: Laminar venting system reduces turbulence and port noise, providing low distortion and extended performance at higher volumes.
 
Technical Specs:
 
Bandwidth: 29 Hz–100 Hz (‑10 dB)
Driver: 1 × 21″ neodymium LF driver
Max SPL: 138 dB
Impedance: 8 Ω; IP Rating: IP55 for indoor/outdoor use
Weight & Build: 46 kg (101 lb); made from durable birch and poplar plywood with reinforced rigging options
 
Applications:
KS21 is ideal for adding low-end impact to small-to-mid scale live events, festivals, and AV productions. Whether flown or stacked, it provides a flexible, plug-and-play solution that pairs naturally with the A Series and other L-Acoustics systems.
 
Benefits at a Glance:
 
Compact footprint, big bass
Engineered to match A15, Focus/Wide
Road-ready design with IP55 protection
Flexible rigging, stackable, flyable, scalable