Jim,
Disturbing the wavefront was my concern as well. Without an array wavefront simulator of some kind it's hard to imagine all the wave interactions in my head. I plan to get some drivers in the near future and play with some cabinet mockups and we'll see what happens. I'm sure you're right, but I have this curiosity inside me to try out a stepped baffle and see what it sounds like. Maybe I'll get ambitious enough to do that someday. By the way, do you have any thoughts on how the new CSS WR125ST would work in an array? I'd like to build using high-quality components to get a very high performing speaker, and have my eye on the 16-ohm version of this driver, to be paired up with an array of either BG Neo3 or Fountek JP-2 tweeters. The link for the CSS driver is:
http://www.diycable.com/main/product_info.php?products_id=533
Thanks,
Dave