Quote Originally Posted by bowtie427ss View Post
I made mine with the same 30-31/32 inch radius as the 828 and 817 flares. I've never seen a drawing that was fully dimensioned for the 816, so i don't know if this is right or wrong, but it worked for me.
I've never seriously considered building any, so I never paid much attention to that aspect of the plans..... from what I've read on horns they're conical, parabolic, hyperbolic, or quadratic. I didn't know Altec used a simple radius, which I assume approximates a section of a parabola. I just looked at the plans for the 825, and sure enough it's 30& 31/32..... seems like kind of an odd measurement to me. The sheet for the 211 doesn't specify at all, and the 815 plans don't give a radius, but rather a width every 4 inches. Unfortunetly, I don't seem to have 816 plans...... lost them during a hard drive mishap about 2 months ago :-(