My dealer suggested using the same mid and tweeter as the rest of the front stage, said they have tried using a Morel Center channel with Dyn door speakers and found that the difference in sound quality of the 2 different brands of speaker would over power one or the other. Maybe the Helix DSP Ultra “RealCenter” overcomes this? Didn't really want to add a 3rd Dynaudio mid and tweeter set to my X6 build but am now leaning that way.