I'm going minimalist / vintage with it's foundation the old vintage KLH 4.5 inch full range drivers found in the models 14, 19, etc. paper cone, cloth surround, BIG alnico magnet & motor structure. I'm mounting them open baffle on a fairly narrow baffle (12.5 X 48 inches). eight per side.

For the low-end, I'm staying with vintage KLH: a single 60's vintage Model 6 per side, stuffed in the corners of the room to (somewhat) match the efficiency of the array. For the high-end, I'm using a NOS pair of Radio Shack dual radial horn tweeters. Crossover is VERY minimal; seated listening posiition is only about 6 - 8 feet away, so comb filtering isn't too big of a deal. I'm running off tubes: either a vintage magnavox EL84 PP amp, or Sherwood S-8000 (7868 PP). If I REALLY want to shake the house (movie night) I run them off my Marantz 1152DC (125 wpc @ 4 ohms).

The sound has impressed anyone who has listened to them; very revealing. I feel the OB design really helps with the transparency. They sound best about 2 feet from the back wall. I eventually want to implement an active crossover w/ digital EQ for full flexibility and optimization. The klh FR drivers should start comb filtering around 1200-2400 Hz, although I havent measured them. . . they sound very good to my ears. Will try and do a full ribbon tweeter array eventually also, as I know the little Ratshack tweeter is a compromise . . .