You shouldn't have any problems as that thing is supposed to drive difficult loads and actually double as the impedence is halved. Why MF makes no mention of this in their specs is completely stupid on their part.

I'm basing this on a review I found at Good Sounds. The money quote, " A good indication of this is the M6i’s power delivery into low impedances, which doubles into 4 ohms (400W), and again into 2 ohms (800W). In fact, MF claims that the M6i can pass 45 amps peak current. It’s perhaps not an arc welder, but darn close!"

I don't think you could buy speakers that this thing couldn't crush.