Ron, welcome. The center channel information is "maintained" just as discretely when it's played by the mains; speakers always have to play a multitude of different sounds and the center info is just another category.

Your proposed arrangement would have one of the two benefits that a separate center speaker can have: the ability to adjust the level of the center channel independently of the mains, to try to make low-level dialog more understandable. The second benefit, anchoring dialog to the center of screen, wouldn't be realized; the center image would shift to the side along with the position of the listener, but not farther out than the center channel speaker on that side. This is the same result that occurs when the mains are playing the center channel.

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Enjoy the music, not the equipment.