when i was still using klipsch speakers i used 2 centers on either side of 5 foot wide entertainment center with great results, & did not notice any sound problems from having 2 centers, but both were set up equidistant from the listening position. i did not ever do any serious listening outside of the "sweet spot" listening position, so can't say if it can cause a problem or not. what i can say is that if you have the ability to use 2 floor standers as a dual center channel it makes a significant difference for both music & movies.