You already know that A4 sits at 440 Hz. But when a snare is ringing somewhere around 300 Hz and you're not sure if that's a D4 harmonic or just mud, do you actually know which note you're chasing? Most producers sweep a parametric EQ band back and forth by ear, hoping to stumble onto the offending frequency. That works eventually, but it's slow, and it trains your ear on frustration instead of precision.
There's a faster path. Musical notes and Hz values have a fixed mathematical relationship under equal temperament tuning, the system nearly every DAW, synth, and mixing plugin defaults to. Once you have that relationship mapped out, you stop guessing and start targeting. This is the chart that makes that possible, plus the workflow for actually using it inside FabFilter Pro-Q, Melodyne, or whatever analyzer you've got open right now.
The note-to-frequency chart (C1 through C7, A4 = 440 Hz)
Equal temperament tuning divides every octave into 12 equal semitone steps, and the whole system is anchored to A4 at 440 Hz, the reference pitch MusicTech's own explainer on pitch and frequency uses to demonstrate the formula (musictech.com). From that anchor point, every other note's frequency is derived mathematically: each semitone up multiplies the frequency by the twelfth root of 2, and each octave doubles it. That's why A3 sits at exactly half of A4's frequency, 220 Hz, and A5 sits at exactly double, 880 Hz, a relationship the source article confirms directly.
Here's the natural-note reference table across seven octaves, rounded to two decimal places:
| Octave | C | D | E | F | G | A | B | |---|---|---|---|---|---|---|---| | 1 | 32.70 | 36.71 | 41.20 | 43.65 | 49.00 | 55.00 | 61.74 | | 2 | 65.41 | 73.42 | 82.41 | 87.31 | 98.00 | 110.00 | 123.47 | | 3 | 130.81 | 146.83 | 164.81 | 174.61 | 196.00 | 220.00 | 246.94 | | 4 | 261.63 | 293.66 | 329.63 | 349.23 | 392.00 | 440.00 | 493.88 | | 5 | 523.25 | 587.33 | 659.25 | 698.46 | 783.99 | 880.00 | 987.77 | | 6 | 1046.50 | 1174.66 | 1318.51 | 1396.91 | 1567.98 | 1760.00 | 1975.53 | | 7 | 2093.00 | 2349.32 | 2637.02 | 2793.83 | 3135.96 | 3520.00 | 3951.07 |
Bookmark this table or screenshot it into your DAW project folder. It covers the practical range of almost everything you'll mix: sub bass sits around C1-C2, kick fundamentals usually land in the C2-G2 range, vocal fundamentals for most adult voices cluster around C3-C5, and cymbal shimmer and air extend well past C7. If you need sharps and flats, split the difference between adjacent columns; a C#/Db always falls between its C and D neighbors.
Using the chart with your EQ's frequency analyzer
Having the numbers is only half the job. The real speed gain comes from cross-referencing the chart against what your EQ is already showing you. FabFilter's Pro-Q line, including Pro-Q 4, displays the frequency under your cursor along with its distance from the nearest semitone in cents, which is exactly the bridge you need between "Hz value" and "musical note" (musictech.com). See related: vari-mu compressor buying guide: herchild 670n vs rivals for additional background.
Here's a repeatable workflow for hunting a resonance instead of sweeping blind:
- Identify the note that's causing the problem, either by ear, from a keyboard reference, or by checking the track's key in your DAW.
- Look up that note's fundamental frequency in the chart above.
- Place a narrow bell filter in Pro-Q directly at that Hz value and nudge the gain down a few dB.
- Check the cents readout Pro-Q gives you; if the ringing sits slightly sharp or flat of the chart value, that's real-world drift, not a chart error, so follow the analyzer's live reading over the printed number.
- Widen the Q slightly and listen in context with the full mix, not soloed, before committing to the cut.
That last step matters more than it sounds. MusicTech's source piece makes a sharp point about EQ fatigue: every cut you make shifts the balance of frequencies around it, so bypassing the EQ periodically to reality-check your ears is part of the process, not an optional extra (musictech.com).
Cross-checking with Melodyne for pitched material
If the problem sound is monophonic, like a bass line, a lead vocal, or a synth lead, Melodyne gives you a second confirmation layer the chart alone can't. Melodyne displays each note's pitch deviation in cents, so you can see, for instance, that a bass note is landing at +11 cents sharp of its chart frequency, a specific example the MusicTech piece uses to illustrate how tuning plugins quantify drift (musictech.com). That's useful because a resonance ringing at 224 Hz instead of the tabbed 220 Hz for A3 isn't a chart mistake. It's the actual pitch of that specific performance, and your EQ needs to follow the real note, not the theoretical one.
This two-tool combination, chart plus Melodyne, turns an approximate target into a confirmed one before you touch a single dB of gain.
Fundamental cuts versus harmonic cuts: know which one you're making
Here's where the chart alone can mislead you if you don't understand what you're actually removing. Every real-world sound, other than a pure sine wave, is built from a fundamental frequency plus a stack of harmonics above it. MusicTech's breakdown of a vocal sample singing C4 lays this out clearly: the fundamental sits at roughly 261 Hz, the second harmonic lands at C5 (523 Hz), the third harmonic lands at G5 (785 Hz), and the fourth harmonic lands at C6 (1046 Hz) (musictech.com). See a closer look at davinci resolve first tab freeze: how to fix it fast for additional background.
That has direct consequences for how you use the chart:
Cutting the fundamental frequency of a note changes the perceived pitch and body of the sound. Isolating just the fundamental, as the source article demonstrates by brickwall-filtering a vocal down to near-sine-wave purity, strips away nearly all of the instrument's identifiable character (musictech.com). Do this too aggressively on a lead vocal or bass and you'll thin it out badly.
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Cutting a harmonic, on the other hand, shapes tone and reduces harshness or muddiness without erasing the note's identity. If a vocal's third harmonic at G5 is clashing with a synth pad in a different key, a moderate cut there tames the clash while leaving the fundamental, and the singer's core tone, intact.
The chart tells you where each harmonic should theoretically sit relative to a known fundamental. It does not tell you which one is actually causing your problem. That's a judgment call you make with your ears, in context, track by track.
When the tuning standard and your mix disagree
Everything in the chart above assumes standard concert pitch, A4 at 440 Hz, and strict equal temperament math. That's documented, reproducible, and true for the vast majority of modern productions, DAWs, and virtual instruments. It is not, however, a guarantee that cutting the exact chart frequency will fix your problem.
A few reasons the chart and your fix can diverge: a live instrument or vocal performance drifts naturally around the pitch center, as the MusicTech piece notes happens with upright bass in jazz contexts (musictech.com); a track was recorded or produced at a different reference tuning entirely; or the "resonance" you're hearing is actually an inharmonic buildup from multiple layered instruments rather than a single note's overtone. In every one of these cases, the chart gives you a starting coordinate, not a final answer. Treat it as the fastest route to the neighborhood of the problem, then let your analyzer's live cents readout and your own ears settle on the exact address.
Once you internalize that split, between the math you can look up and the mixing judgment you have to make in the room, the chart stops being a crutch and starts being what it should be: a shortcut past the boring part of EQ so you can spend your attention on the decisions that actually require it.
