As a speaker designer, I strive to make my loudspeakers as flat as possible. No response tailoring, only conjugate filters. And for amplifiers, preamps, whatever, the same rules apply. On a personal level, I also usually disable tone controls. I don't like to use them.But then again, I agree that our ears are more sensitive to midrange, especially at low levels. The Fletcher-Munson curves are equal loudness contours, and they essentially represent a response curve of our ears. It's a representation of what our hearing does at different frequencies and different volume levels. So preferences in voicing, EQ, etc. may be related to the frequency-energy distribution of whatever is being played and the volume level it is being played at.