Meredith brought a single PS220, in the upfiring gray "pawn" you see there. Waveguided with BSC to sound the same via one speaker anywhere in the room. He used a mixer to combine left and right before the amp.
It sounded quite good, considering its foam and cardboard construction. He never fails to surprise me, and never disappoints.
The next one in, in case you didn't know that above was a speaker, was Dan Neubecker's new waveguide-omni design. He's been working on the scope of that design for on/off 12 years. I first saw conical waveguides. Then he was using compression driver waveguides from PE, and then they discontinued them. He eventually found enough to finish the project. As it sits, it has AE TD12H woofers upfiring from the bottom cab into the back of a 12" waveguide. The waveguide entrance is left open, and the front inside stuffed. This eliminated the cone breakup very well. The next section has a prosound B&C 6.5" as the midrange, firing at a convex cone in the same stuffed manner. The top was also rather novel. It had 2 tweeters, both variants of SB 29mm textile, with the front conventionally waveguided and the rear out of phase firing into the back of a waveguide. This yielded a cardioidal lobing pattern to give better imaging to the design. He did this as most omnis don't image very well.
While Dan says they were meant for smaller rooms to allow the tweeters to work properly, with a slight resistor tweak they sounded very good!