Given their size, the speakers do a remarkable disappearing act that can only be compared to the best monitor speakers. Imaging, particularly front to back imaging, is uncanny. The soundstage is incredibly wide and deep, and the rear firing tweeter does add some nice elements to the sonic picture.
The mid range is absolutely pure. The highs are smooth, but detailed. As has been mentioned by many before me, the bass response is absolutely stunning. Tight, deep, musical bass that truly goes down into the 20hz range.