K-array has announced its Thunder-KSCARDIO412P passive cardioid subwoofer is now shipping.
First previewed at ISE 2026, the KSCARDIO412P is a compact, single-cabinet unit designed to give professional audio engineers precise low-frequency control without the complexity traditionally associated with cardioid subwoofer systems.
Cardioid subwoofer configurations have long been valued for their ability to reduce unwanted rear sound radiation. This offers a significant advantage in live event and fixed installation environments where stage spill and monitor feedback can compromise audio quality. Achieving this effect has traditionally required carefully configured multi-cabinet arraying, external DSP processing, and the application of delays. The Thunder-KSCARDIO412P is designed to take away that complexity, delivering plug-and-play cardioid performance from a single enclosure with no additional signal processing or time alignment required in standard configurations.
At the heart of the cabinet are four 12-inch neodymium magnet woofers, providing low-frequency response down to 35 Hz and a maximum output of 138 dB SPL. The KSCARDIO412P weighs 61.7kg, making it practical for both touring rigs and permanent installs. The enclosure is constructed from birch plywood with a polyurea coating, built to withstand intensive use and regular transport, and is available in black or custom RAL finishes.
The system supports both mono-amp and bi-amp operating modes, offering flexibility for engineers working with different amplifier configurations. In bi-amp mode, rear attenuation of up to 20 dB is achievable, allowing for highly controlled low-frequency directivity. Critically, the cardioid pattern remains stable whether the cabinet is deployed horizontally or vertically, and in single or side-by-side configurations. This addresses an important practical consideration for system designers working across varied venue layouts.
The KSCARDIO412P is suitable for a range of professional applications, including live touring, theatres, clubs, DJ venues, beach bars, rooftops, and broadcast environments. It is compatible with K-array's K-Framework3 software for system design and configuration.