EQ

From geeksandgod.com Audio processing II Podcast.

Always better to pull EQ's down rather than boost up.

20-20,000 hertz - human hearing

60 - Electrical cycle

Under 80, more can be felt than heard

100-500 (usually 200-250) is the "muddy" range - take this down to get rid of muddy

1k-5k - annoying guitar sounds

5k - magic number for human voice ("Presence")

7k - syballance - "ssss"

10k - "shimmer" - adds "pretty" but can get harsh

above 12k - not much there