It is high power, and cool, reliable operation with precise definition and low distortion. Plug-in data cards for each subwoofer, called SPEX cards, preprogram equalization, infrasonic filter characteristics and power output that best matches the subwoofer being used. Each SPEX card also custom install subwoofers/amp has specific power control circuitry tailored to each subwoofer’s requirements for an even greater level of reliability.