And that may be why I haven't heard a dynamic EQ system that doesn't have a sweet spot on the volume scale. Audyssey XT32 in my current Marantz pre/pro seems to work well for very low volume/late night listening, but it exaggerates the bass at the 70-75 dB level where my family and I spend most of our time. YMMV.
In my stereo system, I spend nearly all my time listening at average volume levels between 75 dB and 85 dB and want my speakers to sound best within that window.
HT: Dynaudio C2, Contour S CX, 2x BM14S, Aperion surrounds, Simaudio Titan, Marantz AV8801, Oppo 103, Linn Majik DS, and a Pioneer Kuro
Stereo: Dynaudio Focus 160, Simaudio W-5 LE or Luxman M-600A, Linn Akurate DSM, 2x Rythmik F12G
Other interests: motorcycling, skiing, being active