Doesn't anyone use search anymore.
Over time (years) Axiom makes/improves their products, through research, development, and testing. Some of these changes can be minor and others might be more significant, but this really is no different than any other mfg.
As far as from V1 to V2, I believe there was some modest changes to the crossover and tweeter driver material. I'm sure someone at Axiom could go into more details. In regards to sound, you most likely would be hard pressed to "hear" any difference.
