Used K-Array Thunder-KMT21 I
Used K-Array Thunder-KMT21 I units offer a powerful active 21-inch subwoofer combined with onboard signal management and processing, making them suitable for demanding medium to large-scale audio applications. The second-hand Thunder-KMT21 I is built around dual 2400W Class D amplifier channels, giving operators flexible configuration options alongside any compatible passive loudspeakers. Scroll down to browse current used K-Array Thunder-KMT21 I listings available now.
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K-Array Thunder-KMT21 I specifications
| Brand | K-Array |
| Segment | Audio |
About the K-Array Thunder-KMT21 I
The K-Array Thunder-KMT21 I is an active 21-inch subwoofer that goes beyond bass reproduction by incorporating dedicated audio signal management and processing. At its core are two channels of 2400W at 4 ohms in Class D: one powering the 21-inch woofer and the other feeding a speakON output on the rear panel. This architecture supports a wide range of configurations, pairing with passive loudspeakers as single mid-high speakers, full line-array columns or additional passive subs to reinforce mid-low frequencies in larger systems. Typical applications include theaters, concert halls, touring and live events, nightclubs, broadcast studios, theme parks, cinemas and large congregations.
K-Array Thunder-KMT21 I — buyer FAQs
What is the K-Array Thunder-KMT21 I and what makes it different from a standard subwoofer?
The K-Array Thunder-KMT21 I is an active 21-inch subwoofer that also functions as a signal management and processing unit. Beyond driving its own woofer, it houses two Class D amplifier channels rated at 2400W at 4 ohms each. The second channel feeds a speakON output on the rear panel, enabling the unit to drive compatible passive loudspeakers directly rather than acting as a bass cabinet alone.
What configurations does the Thunder-KMT21 I support when used with passive loudspeakers?
The Thunder-KMT21 I can be paired with passive loudspeakers in several ways: as a single mid-high speaker, as part of a full line-array column, or alongside additional passive subs to reinforce mid-low frequencies in larger installations. The dedicated second amplifier channel with its rear-panel speakON output is what makes these varied configurations possible within a single unit.
What types of venues and events is the second-hand Thunder-KMT21 I suited to?
The Thunder-KMT21 I is designed for medium to large applications. Typical uses include touring, festivals, concerts and live event productions, theaters and concert halls, nightclubs, broadcast studios, cinemas, theme parks and large congregations. Its 21-inch woofer and dual high-power Class D amplifier channels make it suited to environments where headroom and signal flexibility are priorities.
Who makes the Thunder-KMT21 I?
The Thunder-KMT21 I is made by K-Array. The Thunder-KMT21 I sits within their Thunder subwoofer line and is designed to integrate with K-Array passive loudspeakers, reflecting a system-level approach where a single active unit can manage amplification and signal routing for connected passive cabinets across a range of professional install and touring scenarios.
What should I check when buying a used K-Array Thunder-KMT21 I?
Verify that both amplifier channels are operational, confirm the rear-panel speakON output functions correctly, and check that all signal management and processing features respond as expected. Note whether any passive loudspeakers or accessories are included in the listing, as configurations vary. Used units on 10K Used carry a 21-day warranty covering major functional faults; full details are in the buying guide at https://www.10kused.com/used-av-equipment-guide/.
