Hi Guys, I would appreciate some advice on building a similar dipole speaker to the Dali skyline. I want to use the same trapezoid design with a 40" ribbon the same as the Apogee Centaur. The driver I can get this side of the world that has potential is a Fane 15" model 15_250 it has a q's of 0.7 and Xmas of 4.5mm which is not perfect but I think it will work. The crossover point will be 250 h Z. I would imagine I would need to be at least 3 to 4 foot from the back wall minimum. I was going to be sloped wings from top to bottom tapered.