....you could take the cut-out you made when you drilled/routed the hole, or make a new one out of the same material, and epoxy it into the hole with 'slow-set epoxy for wood'. Wait 24 hours and drill/rout the hole all over again. Cut discs of felt to surround both tweeters which they could use anyway, and the whole affair is your little secret. My fixes are better than Bmars because I have much more practice fixing mistakes:)