I thought this topic had run its course, but curiosity got the best of me and I completed another pair of Art Arrays last week. I also built both the original first order crossover and Pete's higher order version, which are mounted externally for easy comparison. I've auditioned the speakers with both crossovers, and they sound different, but at this point neither emerges as the clear winner. I've ordered some extra binding posts and bananna plugs to permit quick change-out of the crossovers, and next week after these have arrived (and the speakers have had some break in time with both crossovers) I'll do some comparisons with both the Krell and a low power SET tube amp, and will post my observations.
Thanks Fred. I'll be looking forward to your observations. I for one prefer the first order so far.