Oh, nothing special. Just a sort of prototype I made, 15mm pine and/or spruce and 12mm birch plywood, two Eminence Kappa 15A 8 Ohm speakers, 220-230 liters net volume, triangle ports 14cmx14cm length somewhere around 100 mm, flared one end. Tuned somewhere near 50 Hz so it handles 220-250W nicely I think. I was about the get rid of it and make few 1x12" cabs with "premium" speakers but other members of our trio wants the cabinet back so I have to take it back. Have to finish it first, actually working on it at the moment. More or less "Kappa15A Larger Vented Cab, Full Range PA or Bass Guitar" cabinet design from Eminence. Two 1x15" cabs would be better, this cab is ok as long as I don't have to take it anywhere with me!