Jls3, HEA acknowledges that the tweeter looks similar, but insists that that the basic operating principle is quite different, hence their patent in the area. They also have a patent on the manufacturing process. I have spoken to the designer- the tweeter is about 97 db on its own. There are actually two of them integrated into the tweeter module- one front firing and one to the rear.
It is very fast, faster than any conventional dome tweeter, yet fails to draw attention to itself. Frankly, after living with this speaker, its hard to take other monitor-sized speakers seriously, price no object. It really is one of the best ones out there.