Planar center channel w/conventional speakers

Your best bet is to always use the same manufacturers speakers for the front L&R as the center. The idea here is to present a coherent sound all the way from left to right (it's even better to use the same speakers for the surrounds). Mixing brands and attempting to make it sound good is tough enough. My guess is that mixing a pannel speaker with dynamic speakers will probably be awful.
Ken G.

Try avsforum.com
They are really into A/V systems.
If I remember right, Theta includes new center channel options in their current Casablanca processor, which were created specifically to address the limited lower end response of planar & electrostatic center channel speakers....

Daniel

I've done it in a strange way. It was some time ago and I used 2 Martin Logan monoliths as a center channel (they were also the mains for my stereo listening). I then used Klipsch La Scalas as the main left / right for surround. As you can imagine this was a BIG sound. The dialog was very clear and had the benefit of full range (something I miss with my current center channel--even with crossovers set to redirect the bass--it's not quite as good). The mains for surround were very dynamic--you can imagine explosions and such--they were incredible. However, if you watch movies that are not all the explosions and car chases--the benefits stopped. There was no blending of the speakers, and there was no way to get the timbre matched. On some soundtracks this didn't matter. They were recorded in such a way that the channels worked very independently--but for those sound tracks where they tried to blend sounds through the center and to the sides--it just fell apart. Last, I should mention, my case was pretty extreme--some others may have some experience with what speakers might mate well with the Magnapan.