Until recently, I was not aware that a S12X-D was once made (12" with the tweeter). I now have an opportunity to buy one. This interests me because I need a horn somewhere in my cab stack, and I previously thought this would prevent me from stacking a pair of Bag End 12's. Has anyone ever paired up Bag End 12's? I'm wondering what a S12X-D plus a S12-D would sound like. How different would it sound from a pair of 15's or a 12 plus a 15?