On any of the DIY sites such as Solen or Parts Express, you can see a number of tweeters and midranges with tapered tubes or cones attached to them to combat standing waves. This is also why you see some rather odd looking cabinet designs such as pyramids, aside from tapered, curved or ellyptical designs. Others use an angular shape within the cabinet, unseen from outside.

Half of communication is listening. You can't listen with your mouth.