Here's what I notice from the plots:
1) Sag in the midrange at 1kHz when vertically off-axis by 10 degrees. Lots of speakers, if not most, have issues like this due to vertically stacked drivers interfering. It can be avoided with coincident drivers (like KEF). Its audible significance is debatable.
2) General upward trend from 2kHz to 20kHz may make them seem bright.
3) Off-axis humps ("flares") in freq resp from about 4 or 5 kHz to about 10kHz may make them seem bright and/or forward in the mid-to-high treble.
4) Large peak around 20kHz is likely the tweeter resonances frequency. I can't hear that high. You might? Very little program material energy there, so of questionable significance.
5) Glitches in the impedance plots at 150Hz and 300Hz are likely from cabinet resonances. Tough to determine whether or not these are audible. Depends on their Q factor, magnitude, surface area, and many other factors.
6) Glitch in the impedance plot just below 20kHz is the tweeter resonance frequency. Audibility in question as described above.
6) Impedance magnitude drops below 4 Ohms from about 100Hz to 200Hz. This will draw a relatively high amount of current in a region with a lot of energy (mid to upper bass). But is ameliorated by the speakers relatively high sensitivity. In a big room, playing very loud, will stress an amp, but otherwise OK.
7) Impedance phase angles are all over the place and often exceed 50 degrees. This could make them a tough load. Fortunately, phase angle is low where the magnitude is low (100Hz to 200Hz), so not as big as issue as it could be. Still, pretty high phase angles, so it will be somewhat taxing on the amp. I would get a good solid-state amp or AVR rated to 4 Ohms.
8) The waterfall/CSD plot shows big ridges of resonance at around 12kHz and 18kHz. The lower of the two might be more audible as a very high frequency ringing. Not much program energy at this high frequency, but could be audible as a sharp piercing quality to the sound if the resonance is excited. The higher one is too high for me to hear but could do the same thing as the lower one if it's excited.
Overall impressions: Meh. I've seen worse measurements from that site. I've seen better too.
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