IF you mix brands, I bought this Klipsch Center Channel , soundss very nice. Importantly, NO REAR PORT
It is very efficient, thus you want efficient L/R. Your AVR will adjust volume, but within limits.
Prior center channel was a Bose, little guy fit prior smaller height setup. but very successful, less efficient, works with more typical medium sensitivity
surprisingly good, very small, place to allow top vents near front to work.
................................. btw, IF you skip center channel speaker, and listen to a program with center channel content, that content will not come from just L/R unless you change your AVR to 2 channel mode.