I have been using a pair of Alpha 15 woofers in 7" deep U-frames with Fostex 166en fullranges on top for a while now, after experimenting with other drivers. The boxes look a little funky and were always intended to be temporary until I decided on the WAW combination and crossover that worked for me. I would like to build the same drivers into a better looking system, and maybe try a different load on the woofers. Has anyone tried the same 15" woofers in both an H-frame and a Nelson Pass style SLOB configuration? I heard the SLOB, with different woofers and Lowthers on top, at a Burning Amp festival and liked what I heard. They looked good, too, to my eyes. Given that the drivers in the Pass SLOB were completely different than what I have, I am not sure I can generalize about the merits of slot loading. I have not had the pleasure of hearing an H-frame system. Anyone have an opinion about which style I should try next?