Prominence 0
Fletcher-Munson curves 0
The Fletcher–Munson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by Harvey Fletcher and W A Munson, and reported in a paper entitled “Loudness, its definition, measurement and calculation” in J.Acoust. Soc Am.5, 82-108 (1933).
from Wikipedia
Moral of the story, mix at low volumes.
