Wayne Parham Messages: 18786 Registered: January 2001
Illuminati (33rd Degree)
I think what you're seeing is the wide-angle off-axis curves fall off more rapidly above 2kHz. It is apparent in the 50° response curve, and while they aren't shown, this is even more noticeable in the response curves taken further off-axis, outside the flare wall angle. But up to +/-45°, the off-axis curves fall off at pretty much the same rate, which is a signature of constant directivity.
Woofer beamwidth narrows to 90° around 1.2kHz, and the waveguide is starting to gain directivity control in this region too. I'd say it has full control by 1.5kHz or so, and horizontal directivity becomes constant 90° above that point.