I always thought it has some other benefits like providing a high powered sub with cooler air to its VCs. Look at a sub especially a flat piston type more common nowadays it seems that inverting it would cause a much quicker compression of air withing a given enclosure space? The back of the cone is indeed "cone shaped" like a point of an arrow so to speak, which means it would displace or compress the air within the chamber but wouldn't it be more subtle of a way of doing it instead of using the blunt end (face)? You would think the flat face would move more air than the back, isn't that the reason for flat faced subs? Just curious myself... Polo..