Hyperbolic Horn - parametric

Hyperbolic Horn defined by Salmon equation. Horn can be parametrized - you can change horn throat radius, cut-off frequency, T parameter, length, wall thickness, etc.
You can find more details here:
https://www.grc.com/acoustics/an-introduction-to-horn-theory.pdf

OpenSCAD does not allow to create parametric curves so I have designed it using Autodesk Inventor. Inventor file is attached.

A project using this horn:
http://www.thingiverse.com/thing:1925707

You can also check my parametric Folded Horn design:
https://www.thingiverse.com/thing:3133987

UPDATE 12th Jul 2019
The original ipt file does not work in Inventor 2019 - probably issue with cosh function.
Attached is a new file modified for Inventor 2019.