kenwood amps to clip like crazy?

I've heard other wise, those subs are fairly fragile, relatively speaking, not somehing that you can beat up on get away with. They aren't really spl monsters, I believe their purpose was to sound good. 

hmmmmmmm interesting.....ya that kinda makes sense. back in the day the focal kevlar subs were rare in shops. and only a few people in the cities of canada had them i think. and my friends bro had one and he blew his. anyways in any case these amps rock. i like them.......so far. but im just trying to understand all the switches on this thing. like the infrasonic switch and the extender......i know what the bass boost does...and that switch is turned off. can anyone explain to me what those two do!?xTimx