Welcome! I'm building a center channel speaker for my home theater I'm using the Peerless 830-344 "Carver replacement woofers" that were given to me by Hong. I got real lucky when Shawn Adams volunteered to design a crossover.
After messing up the first baffle I found a piece of 3/4 birch and flush mounted the woofers. At HT guide forum they seem to think birch is ok, but prefer the pricey stuff...
Shawn is designing the crossover for a Seas tweet, I just set this Dayton tweet there for this picture...