Need idea! Extreme horn stand

[rendoman]

Hi all!
My last project is a conical horn for a big compression driver, the unit Nt1003L from Hiwell. Neodymium magnet, titanium large diaphragm 4", exit 2", according to measurements perfect for Hi-end use from 450 to 5000 hz, out of the box, with some mods it's possible to extend the lower end.

The turret has a flat bar, the angle has to be adjustable in order to match the axis of the listener, according to speaker height. A threaded rod would be the fast solution, the micrometric steps would be very nice, above all with a knob (spring plus ball).
I'm thinking about bulding a sort of mechanical piston, I'm searching for something nice to see also.
Any advice welcome!
Thanks!

[awright]

Very nice looking woodwork, rendoman, but I don't think you will get an acoustically pleasing result. The purpose of a horn is to smoothly transform the acoustical impedance of the (relatively) small throat of the driver to the acoustical impedance of the free air at the mouth of the horn. For this to be accomplished smoothly the horn must have an exponential flare, not a conical flare. This is why you see most, not all, brass and woodwind instruments having an exponential flare. I am not near my library right now but, as I recall, the classic book, "Elements Of Acoustics" by Harry f. Olsen discussed the properties of horns many decades ago. The rate of flare is also critical to smooth transition from the impedance of the driver to the impedance of the throat of the horn. The flare rate of your conical horns looks much too great in the photos. Obviously, making exponential horns is far more difficult than making conical horns, especially in wood.
awright

[rendoman]

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