PE is supposed to come out with a very low distortion RS series 3 inch midrange with high Xmax which might raise the bar on my current design, and then I could go with them. I've not seen a dome tweeter of higher quality that can be made with a center to center distance of closer than about .8 inch that fits the parameters of the current design. Using thirty of them per side drops the distortion down to pretty low levels. Using thirty tends to flatten the FR over an average.

If I changed the design to a larger midrange then I could buy a more expensive one, but then that would require that I go to B&G Ribbons which are not part of my design since I prefer the tweeter sound of domes, and to get a similar low distortion I would need to have a double row of the ribbon tweeters which I'm not sure is possible. I would have to lower the crossover, and the domes would no longer work. I would need larger diameter tubes or would have to go with Sono-tubes.

I could upgrade the amplification equipment, but I would only do an ultimate system if I could hear a difference. I've no evidence that I could.

I'm not sure this answers your question. My design was very carefully worked out initially based on very specific parameters which I designed at the beginning. I spent a lot of time in the design phase before I even began building.

For me, the current design is at the ultimate level. Another design might be better, but I've not looked into modifying the design since I continue the be extremely happy with the sound I have now.

I'm one of those people who when I reach the 96% level, I don't spend all my time trying to inch up to the 96.5% level, but just spend my time buying music and listening to it.

Marlboro