DYNACORD PWH 28 is a high-power double 18-inch subwoofer in Planar-Waveguide-Basshorn-Design. The PWH 28 can be integrated without any problems in Cobra-Systems for setups in medium- to big bass-arrays. The cabinet is equipped with an electronic circuit called Voice Coil Tracking Protection. This circuit senses the terminal voltage of the transducers and simulates the thermal behaviour of the woofer's voice coil. Millings on the top and at one side allow easy stacking of cabinet.