Talking to Victor Sierra at VSAC, he showed me a prototype 500Hz horn with a special flare rate for the TAD TD-2001. Supposedly, a stock tractrix on the 2001 will limit HF response. BTW, this has been my impression in the past of the Edgar salad bowels, a little too down in the top for my tastes.

Anyway, I visually compared the the revised flare horn with a stock S/B 500Hz horn, and in the 2001 model, the throat appeared to be conical to about 2/3 the depth of the horn, with a faster flare at the mouth.

With the new flare, he said it was flat to 20kHz. Like to try it (as soon as I get some work!).