I personally cannot hear the differences between the HA and radians. The cone materials do look a little different though. I don't know if it effects the crossover point. Hemp cone (from banana plants btw) supposedly have less breakup, so maybe the crossover point may change. On the same radian crossover, open baffle, there is no audible difference that I can tell. Can't speak for my friend, but I probably don't think I'd pay double for the driver.