The Behringers are marginally better than the Ranes. But you can use them to find a filter curve for the horns. The horns are quite nonliear.
The vented boxes will output some midrange through the ports. Limiting this midrange (throuch damping material) will improve sound. Or you could rebuild the boxes with a 8-12 inch midrange in a dogbox replacing one 15 incher, creating a 3-way system.