I'm surprised nobody has mentioned Von Schweikert speakers in this discussion of time and phase coherent speakers. Anybody have any opinion on Von Schweikert speakers as they fit into this discussion? BTW, I asked Albert Von Schweikert how he achieved time and phase coherence with a 4th order crossover. He gave me a very lengthy response to my e-mail, which was very interesting, but I am not sure he answered my question. Can anybody help ?