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Thunder-KS3 l

Thunder-KS3 l

The Thunder-KS3 l is a compact active subwoofer featuring a 21” cone driver and a powerful 4x 2500W @ 4Ω audio amplifier module with built-in DSP.

The audio power output connectors allow the Thunder subwoofers to drive a wide range of K-array passive loudspeakers. Compatible with midrange loudspeaker and other passive subwoofers, the self powered Thunder subwoofers with DSP are designed to be the core devices in K-array sound reinforcement systems.

The dedicated K-array Connect mobile app provides an user friendly interface for remote control of the DSP main parameters and easy configuration of the signal routing.

More information about the Thunder 2022 line

Find That Deeper Bass

Are you looking for a deeper sound, higher sound pressure and better tonal definition? A new design approach with the KS versions further extends the sound reproduction in the low frequency and promises a significant increase in SPL performance.


Giving You Ultimate Sound Control

Simply combining two or more subwoofers to obtain a configuration that guarantees cardioid diffusion even throughout the low frequencies promises to give you a cleaner sound on stage, minimise risk of acoustic feedback, and in general a greater control over sound design the way you want it.


Crafted For Heavy Touring

The Thunder Series subs are built with a choice of Finnish birch plywood so it isn’t heavy and cumbersome but it is incredibly resistant, making it a desired speaker for audio rentals.


Adaptable, Even Off The Stage

Thanks to K-array’s signature compact style, without trying to be defined as a design product the Thunder series can easily adapt to architectural installations or even wedding events in the open air where blending in is of great importance, also thanks to the possibility of a custom painting on demand.


Obsession For Details

The details can really make the difference, the side handles are elegantly integrated into the speaker body beautifully crafted for comfort.


Extended Line Array

Among the Thunder-KS accessories, one of particular importance are the mechanics for hanging in arrays which allow it to be suspended in combination with the line array speakers of the Mugello family, and in clusters composed exclusively of subwoofers.


1 X 4

In their active version, the Thunders are more than just subwoofers. They include a powerful 4-ch class D amplifiers fully managed by sophisticated integrated DSP processors.


Embrace New Skills

The new Thunder-KS integrates a new generation intelligence software (osKar) that allows you to manage the entire ecosystem through various control platforms and offers various features directly on board the device, in order to simplify its use and extend its application possibilities.


Updated Control Softwares

The remote control of Thunder-KS subwoofers can take place through three different types of software released for free, starting from the most complete K-framework for Windows and Mac, passing from a more intuitive web app and arriving at the more simplified mobile app (Wi-Fi).


Quiet, Even If It Rains!

With a particular focus on audio technicians and rentals, the amplifier of the new Thunder-KS line features a PowerCon True connector for powering the mains, allowing easier wiring extension and greater resistance to bad weather.




  • Type Active subwoofer
  • Transducers 21" neodymium magnet woofer
  • Frequency Response 35 Hz – 150/450 Hz (-6 dB) crossover dependant
  • Crossover DSP-controlled, Low Pass @ 150 Hz, preset dependant
  • Max SPL 139dB
  • Rated Power 2800W peak
  • Coverage Omni
  • Connectors Line Input: 2x XLR-F analog / AES3 Line Output: 2x XLR-M Link analog / AES3 Speaker Output: 2x SpeakON NL4 Mains powerCON TRUE1 TOP Networking and Data: 1x RJ45 4x USB-A

Handling and Finishes

  • Dimensions (W x H x D) 735 x 580 x 700 mm (28.9 x 22.83 x 27.56 in)
  • Weight 56 kg (123.4 lb)
  • Material Polyurea coated birch plywood
  • Color Black, White, Custom RAL
  • IP Rating 53
  • Output Power 4 x 1500W @ 4ohm
  • Power Consumption 600 W @ 8 Ω load, Pink noise, 1/4 rated power