Thunder-KMT21 I

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 2400 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.



Type : Active subwoofer   

Transducers : 21" neodymium magnet driver  

Frequency Response (1) : 30 Hz – 150 Hz (-6 dB)    

Maximum SPL (2) : 136 dB peak

  • 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


Amp Module  : 2 ch. switch-mode, class D     

Output Power  : 2 x 2400 W @ 4 Ω         

  • Power consumption : 600 W, 1/8 Rated Power (Pink Noise)


Dimensions (W x H x D) : 555 x 572 x 763 mm (21.8 x 22.5 x 30 in) (3) 

Weight : 44 kg (97 lb)           

Material : Wood  

  • Color : Black, White, Custom RAL



IP Rating : IP40(4)

Notes for data:

(1) With dedicated preset

(2) Maximum SPL is calculated using a signal with crest factor 4 (12dB) measured at 8 m then scaled at 1 m

(3) Included 17 mm (0.7 in) removable rubber feet
(4) IP43 with K-AMPCOVER.