Yep, also FYI, when you "clip" your amp, it is capable of putting out over twice its rated power, but in a square wave. So basically clipping is very bad and is probably the main reason most subs get blown. People will think that since their amp is rated at 600 watts and their sub can handle 800 watts, they can crank the volume, gains, and bass boost, and think their sub is safe from blowing nomatter what.
Basically a square wave is high voltage DC that pulsates. It will potentially overheat the voicecoil of a speaker and exceed the ability of the amp output devices to disippate heat and potentially cook them as well. All in all it falls into the bad category.