center channel problem


I have a new home theater with thiel 3.6s as my fronts, marantz preamp, and parasound 5250 amp. Center is a thiel scs3. i'm very dissappointed with the scs, boxy and muffled. Dialog is uninteligible. Any thoughts on how to improve the center channel or a good center channel to match the 3.6.

BTW I tried the 3.6 in the center and it sounded great (but covered half the screen).
datrmn8tr
make sure the tweeter is working. this exactly described a problem I had, and my center channel tweeter was blown new out of the box.
I use an scs3 and it is clear and crisp, just the opposite of what you discribe above. Either the tweeter is blown or your surround sound processor is not working correctly.