Hi! Thank you!
About the choice of the horn type, I decided to try conical because it was the last profile to try in my system. I built (or tried in the past) tractrix, exponential, Iwata, Smith and Fostex radial for home use.
Conical is not well seen in commercial field, I could be wrong but I think the only one commercial brand left is Oswalds Mill Audio. Surely expensive to build, lot of parts to glue and put in place with good tolerances, other round horns are easier to build with lathe or cnc. Furthermore they are heavier, larger and less efficient than exp or tractrix for same cut off frequency, also not suited for bass.
A good thing is the expansion rate is constant, the wavefront is not not modified as in a curved profile. The dispersion is also increased (withing the limits). This horn in particular will be used as pure midrange, so no big problem about high frequencies.

https://oswaldsmillaudio.com/imperia

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