Well, after nearly 5 years of having these "loaner" horns from my buddy Ashley, I finally got around to testing the 20-something year old USD Audio A-6.0 horns and even had a word or two of input from the designer himself: Eric Holdaway.
I put in roughly 8 hours total in testing and posting these results. I tested these horns to the degree (no pun intended) I've never tested before: full 180 degree sweeps at 15 degree intervals in both the horizontal and vertical axes. This was necessary to show how the shape of the waveguide, at least in the horizontal axes, alter the response. From this, you can tell a lot about why and what the purpose was (ie; 2-seat cars).
The owner said he thinks he has the original EQ parts somewhere, so maybe I'll revisit this later. But for now, I'm donezo! Enjoy!
http://medleysmusings.com/blast-from...a-6-0-testing/