What happens to an amp below 2 ohms?

Very few amps will handle such a load but I know of only 2 speakers myself that go below one ohm: the aforementioned Scintilla and the Quad 57. The latter does this in the top end so is not nearly as difficult a load to drive as the Apogee. In a perfect world the impedence curve would stay above 6 ohms but in our world some very good speakers have difficult curves. My Gamut L5s go down to 3.2 or so and my friends Sasha to below 3. The amount of work my CJ 350 has to do driving the Gamuts is considerable, gets quite hot driving them to a good volume in a long session. On the other hand it gets barely warm driving my Spendor S 100s to a similar volume. A good reason why you should always buy the speaker first; then you know what your amp requirements will be.