Three Pi speaker with a Fountek ribbon supertweeter. The three Pi is a great design, and ultimately I found I preferred this speaker without the supertweeter.
The "Talleray", standing 7' 4" tall, is an open back dipole line array featuring fourteen 5.25" Foster extended range midwoofers and an Eminence compression driver mounted to a Dayton waveguide. Impedance is 7 ohms, sensitivity is about 96dB. The midwoofers run full range; the tweeter crossove is a 2nd order.
All dressed up and ready to party! This turned out to be a REALLY BAD SOUNDING speaker, but it was cheap to build and could play REALLY LOUD, so I gave it to my nephew who thinks it's the best speaker he's ever heard.