The older (V1) 100's could dip to about 1 ohm which can cause problems for some amps, especially when being driven hard, and damage your speakers - most likely the tweeter. I don't know if the new 100's impedence curve is the same as the V1's or not. In my HT, I drive the my 100's with a separate amp from the receiver preamp outputs. You just need to make sure you cover all bases.
