☀ Eye Heru 369 · Studio Reference Tool
Key / Frequency Mixing Tool
Every musical note in every key with its exact frequency in Hz, from octave 0 (16 Hz) all the way to octave 12 (126 kHz). Two sections: 12 keys to boost showing every in-scale note you can safely lift, and 12 keys to cut showing the out-of-key notes to watch when something clashes in your mix. All frequencies use equal temperament, A4 = 440 Hz.
Step 1: Select Your KeyPick your song’s key from the selector below. The chart will highlight your key’s block so you can find it instantly.
Step 2: Use Your EarSweep your EQ until you find the problem frequency. Note the Hz reading on your plugin.
Step 3: Type It InEnter that Hz in the finder. With your key selected, it tells you exactly whether that frequency is in key or out of key for your song.
Step 4: Cut or BoostIn key and sounds good? Lift it. Out of key and clashing? Try a narrow Q cut at the exact Hz shown.
Select Your Key
Select your key above first, then type a frequency here to see if it is in key or out of key.
Select your key above, then sweep your EQ and type the Hz here.
BOOST 12 Keys – In Key every in-scale note, all octaves · safe to boost
CUT 12 Keys – Out of Key notes outside the scale · check these first when something clashes
Muddy 200-500 Hz
Boxy 300-600 Hz
Harsh 2-4 kHz
Sibilance 5-8 kHz
Brilliance 8-12 kHz
Air 12-30 kHz
Ultrasonic 30 kHz and up
Ear first, chart second. Octaves = double or halve the Hz. Cut with narrow Q (2 to 6), boost with wide. Out-of-key frequencies are not automatically wrong. Only cut if something clashes. Ultrasonic air-band moves shape harmonics and presence in the audible range. Moves above 22 kHz require 88.2/96 kHz sessions or an EQ with oversampling.