I’ll post some of our measurements tomorrow (I left one of my measurement laptops at home).
As Paul mentioned, the dips you see in the response are because of a broken/malfunctioning tweeter (where the diaphragm is pinned against the magnets from air shipping). Again, we found the cause and fix and this affected a rather small number of units and can be corrected by placing a small pinhole in the rear chamber of the tweeter (or simply replacing the tweeter).
I did some Klippel NFS testing on a previous prototype but the NFS system has some significant errors at lower frequency (though that issue hadn’t been acknowledged by the lab). I understand that Andrew Jones and Laurie Fincham (who used to head the AES committee on loudspeaker measurement standards for many years) may be doing an AES paper comparing various measured results versus the Klippel NFS. I still think it’s a cool tool and want one but it left me scratching my head versus careful ground plane and close mic / summed measurements below a couple hundred Hz.
HiFiNews’ response below 1 kHz is correct and unaffected by the tweeter issue.
Here is a gated measurement of an aspen FR20 at 0, 10, 20, 30 degrees horizontally.
Here is a contour plot of the horizontal directivity and a directivity index measurement showing that things are pretty smooth and constant through the mid-treble crossover region (without a narrowing in the midrange and flare at the bottom end of the tweeter.
Directivity index and ERDI
Bass Extension (2 pi ground plane measurement)
