Very informative write-up, Rob. [QUOTE]I'm also firmly of the view that some of that 57 magic is directly related to the treble dispersion which is extremely tight. You really do have to shuffle around and 'lock-in' to the speaker and I think that this enhances the feeling that you're coupled to the music. The 63 doesn't do this to anything like the same degree but is no worse for it IMO.[/QUOTE] That's one of the most attractive "flaws" with the best horns and electrostatics I've heard. Oddly, my SBLs exhibit this same trait not due to beaming I would think but more of a rise in the upper mids or lower treble I suppose. regards, dave