I like DI matched two-way speakers because they provide good performance in a relatively small package. But I also like the idea of using room corners, which constrains the radiation angle. The speakers need only be designed to sit snug in the apex so radiation is done within 1/4λ from the wall. This is one way to get directional control at lower frequencies from a relatively small horn. DI is set at 9dB, and is that at 500Hz and below. The only requirement is that the horns be designed with a 90° flare angle and be set within 1/4λ from the wall so that the lower frequencies use the wall angle as flare extensions, effectively forming a very large CD horn.