The band anchors
100 Hz
boom, weight, kick-drum body
200 Hz
mud when excessive, warmth when right
400 Hz
boxiness - singing into cardboard
800 Hz
honk, nasal midrange
1.6 kHz
presence edge, forwardness
3.2 kHz
harshness, bite - ear sensitivity peak
6.4 kHz
sibilance, sizzle
12.8 kHz
air, sparkle, shimmer
Hear any single frequency in isolation on its landing page (100 Hz, 500 Hz, 4 kHz...) or sweep the whole spectrum with the sweep generator. The written map is in the frequency chart guide.