I ran into this thread somehow and the "junk" comments someone made bothered me looking at the graphs....
It sounds to me like Audyssey was correct in your room at the time (the room can affect the results quite a bit; I've had 55Hz speakers register as 40Hz before because of a room bump).
I drew a relative midpoint in red. The Pro Monitor (or was it Cinema) 1000 zero point is right around 87dB on the scale and the ProMonitor 2000 around 77dB. That makes the -3dB point 84 and 74 respectively or right around 45-50Hz in both cases (I think the 1000 is rated for 47Hz). The speakers in question are more or less +/- 3dB (1000) and +4/-3dB for the 2000 graph from 80-18kHz as well (+/- 3dB is typical even on many higher-end speakers). Not the best (fairly common response for a slightly above average bookshelf), but hardly looks to me like the "junk" speakers someone here proclaimed and easily corrected by Audyssey or Dirac at a typical 80Hz crossover point. I think Sound and Vision uses close-mic measurements, which aren't quite as accurate as an anechoic chamber, but should give a close approximation.
Moreover, the point where it starts dropping 24dB/octave is right around/near 45Hz down to 22.5Hz, plain as day, just as specced (I believe ProMonitor 1000 is rated 47Hz).
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If you want more innate accuracy, go PSB. They rate to +/- 1dB over most of the frequency range. That's the brand I chose.