I recently finished constructing a pair of walnut h9800 horn copies based on the drawings put together for project May. Unfortunately I don’t have the computer automated machinery they used for the prototype horn, so had to go a little less hi-tech.
Basically the method was:
• reproduce one half of the horn profile in a sweeping 40 inch arc
• cut these blanks to shape with the secondary profile
• integrate in the horn mouth
I don’t have a lot of pictures of the actual construction, but the key piece of machinery was an overhead router fashioned from a sturdy old 12 inch industrial radial arm saw. With a little extension of the travel for the overhead arm, this gave an easy way to adjust vertically, backwards and forwards, and the proper arc.