Not just an active 21-inch subwoofer, the Thunder-KMT21 I is also a proper instrument for the management and processing of the audio signal. At the heart of the Thunder-KMT21 I are 2 channels of 2000 W @ 4Ω in Class D – one dedicated to the 21" woofer and the other connected to a Speakon output on the rear panel – allowing different configurations in combination with any of our passive loudspeakers such at single mid-high speaker, entire columns of line arrays or other passive subs as reinforcement of the mid-low frequencies in larger applications.
With a 21" woofer, the Thunder-KMT21 I is ideal for medium to large applications where high quality, powerful sound is required.
Unique Performance-to-Size Ratio
Produces an impressive high-power performance by producing a high SPL from a small frame.
We created a portfolio complete with lightweight products that are easy to transportation and quick to setup optimizing logistics, space, labor costs and time.
Four-Corner Port Configuration
The unique four-corner port configuration provides symmetrical back loading to the speakers, for extended bass response with very low distortion.
We have the ability to customize your project by color matching your system to any RAL code to help you to better integrate the speakers into a wide variety of venues.
We utilize the most durable and resistant materials when developing our products to protect and conserve the system regardless of the elements, rendering a K-array installation reliable and long-lasting.
Built-in DSP allows for fine tuning of every single sonic parameter of the loudspeaker, providing the sound engineer the highest control on overall performance and fine granularity in system configuration.
With the dedicated K-dante accessory, this solution can be integrated into a Dante network making it interoperable with other devices.
Our self-powered solutions prevent distortion from cumbersome and fragile passive crossovers and power loss due to long running cables, and offer plenty of advantages ranging from the compactness of the solution to the ease of integration with new and existing sound systems.
- Type Active subwoofer
- Transducers 21" neodymium magnet driver
- Frequency Response (1) 30 Hz – 150 Hz (-6 dB)
- Maximum SPL (2) 136 dB (peak)
- Rated Power —
- Coverage Omni
- Connectors INPUT: 2x XLR (bal) line input, 1x XLR AES3 input | OUTPUT: 1x speakOn loudspeaker output + 2x XLR (bal) parallel line output, 1x XLR AES3 output | SERIAL: 1x XLR RS485 serial input, 1x XLR RS485 serial output, 1x USB-B inlet
- Nominal Impedance —
Handling and Finish
- Dimensions (W x H x D) (3) 555 x 572 x 763 mm (21.8 x 22.5 x 30 in)
- Weight 44 kg (97 lb)
- Material Wood
- Color Black, White, Custom RAL
- Finishes —
- Type 2 ch. switch-mode, class D
- Output power 2 x 2400 W @ 4 Ω
- Power consumption 600 W, 1/8 Rated Power (Pink Noise)
- IP Rating IP40 (4)
- Notes for data:
(1) With dedicated preset
(2) Maximum SPL is calculated using crest factor 4 (12dB) measured at 1 m.
(3) Included 17 mm (0.7 in) removable rubber feet
(4) IP43 with K-AMPCOVER.
Passive loudspeakers require dedicated presets preloaded on K-array amplifiers.
New materials and design are introduced into existing products without previous notice.
KMT21 I DatasheetVer. 2.0
KMT21 I User GuideVer. 1.3
K-framework ManualVer. 2.6
Ease DataVer. 1.4
K-framework 2.2.8 - WindowsVer. 2.2
EASE Focus 3 Download
KMT21 I DWG 3DVer. 3.0
KMT21 I DXF 2DVer. 6.0
KMT21 I PDF 3DVer. 3.0
KMT21 I LayoutVer. 2.1
KMT21 I 3DS 3DVer. 1.0
KMT21 I Architects SpecsVer. 1.0
Amp-to-Speakers TableVer. 2.1
Thunder-KMT21 I can be successfully used in a range of different settings and events.