I run a pair of tweeters with my dual FR, Wonderfullll, Never would go back to a single tweeter.
About to experiment with a trio of tweeters, But I think 1 will be edge out by the 2 superior tweeters.
I note someone mentioned Seas tweeters, Seas are too low senstivitity,
Even their Crescendo rated 92db, I found in actual tests to be like 84db, IF THAT.
A single tweeter in classical music just is too thin. Dual tweeters are a winner