How accurate is Hornresp for simulating a point source horn. When I mentioned it to David Mcbean, his comment was that it's pushing the envelope.
Red: measured near field
As you can see, hornresp did a fair job. The dip around 1.6k is shown higher and above that there are probably some complex behaviours you can't expect hornresp to predict, but overall it's not bad. The overall trend is correct.
Now here is the midrange response, shown raw (grey with the hump at 320 Hz), after EQ (red) and with filters in place (blue).