Adrian, I agree with most of your post, it is common "knowledge" and established theory. The problem is, I have built speakers for 30 years and was a subscriber to Speaker Builder for 20. The reality for me is that "my favorite speaker" simply sounds better than anything I ever designed and built.....regardless of how they measured or the "theory" behind them, or the cost. I hate it when that happens. And believe me I have built a few nice ones in that time using the best drivers available.......I have even built ribbon drivers and magnetic planar drivers from scratch ( I have plenty of ribbon material if anyone needs some). And no, I did not get it "right" the very first time......I started building single driver speakers 10 years ago......and never looked back. Not going to either. 20-20k is overrated. My .02 Ed