Jeff, Ivica, Barry, et al
I'm thinking my first approach will look something like this: 1. Position them as in Post 38, with the 2405s rotated and at the top outer edge of each unit. 2. I'm no Clair audio expert (That's for sure!), but I think they used the four 2123Hs to get maximum mid-range SPL from an efficient set of drivers. Ivica, horizontal dispersion wouldn't seem to matter much when you have a dozen, or so of the S4s side-by-side in a concert.
3. However, I intend on using only the 1st and 3rd 2123Hs (from the outer edge) on first try. Ivica, I'd like to know what your analysis would indicate, in terms of wider dispersion, with that scenario. 4. Then I will attempt to use two 434X crossovers for each cabinet. 5. Connect four 250 watt amps and see if the music 'goes round-and-round, and comes out here'. Then report my failures to the LH forum for all to enjoy!
A plan? Obviously subject to your comments and a thousand changes of mind by me.
Greg