Is there anything similar to the type the Velodyne HGS series uses? It simply limits low-end output when there isn't enough power. I'm hoping to do a LT sub using the Tumult. Instead of designing the Q of the system to be within the capabilities of normal amps, I'd prefer maximum flat extension. At lower volumes, it'd perform as designed, but when pushed too far, the amp could protect itself and the driver by simply toning down the subsonic frequencies.