Wayne Parham Messages: 18755 Registered: January 2001
Illuminati (33rd Degree)
In my experience, baffle step is not a problem for speakers that are boundary loaded anyway. There is only a small frequency interval between where the baffle acts as a boundary and the rear wall acts as a boundary. Since this range isn't sharply marked but rather a transitional area, it is essentially never realized. Besides, once you get down into the room's modal region, any effect of baffle step becomes swamped by room modes.
About the Delta 12LFA and tube amps, please understand that this is something that doesn't concern everyone, as impedance fluctuation isn't troublesome for every amp. Those that are considered "tube friendly" will work on even amps with very poor damping ability. But you'll find lots of tube amps that work just fine with practically every good-quality high-efficiency speaker. I was running Stage sevens and Bill was running his Arrezo's with tube amps throughout the show. Both sounded great, and produced nice deep bass with no audible artifacts or response anomalies.