WWJD?

+1 to what Aux said

Thanks for your response, auxinput......you confirmed what I had felt about mixing the two types of speakers. BTW, I erred in calling the Mirages dipoles - they are bipolar design, with drivers on the front and rear.

In my experience, it is most critical that the left-center-right speakers of a home theater system be all of the same type of driver/crossover. Otherwise, you will definitely get a sense of disconnectedness in the sound as well as weird transitioning sonics as sounds move from left to right. The surround speakers are less important to match, but they do influence things. As far as the Mirage dipoles, I couldn’t comment as speakers are very much a personal taste thing.  If you liked the Mirage, I would recommend you replace the center with a matching Mirage as well.