The mix-up that sits on every fretboard
432 Hz on the guitar
In the forums both sentences stand side by side as if they meant the same thing: “tune down a half step” and “tune to 432”. They do not mean the same thing. A good two thirds of a semitone lie between them — more than enough to pull any ensemble apart.
432 instead of 440
−31,8 ct
Roughly an eighth of a semitone. You hear it in a direct comparison, but no fingering shifts and no string goes slack.
A half step down (E♭)
−100 ct
A whole semitone. E becomes E♭, and every chord name becomes another one. The strings get noticeably softer.
Both sound lower. One is a good three times as low as the other.
The six strings in numbers
| String | at 440 Hz | at 432 Hz | E♭, at 440 Hz |
|---|---|---|---|
| E (low) | 82,41 Hz | 80,91 Hz | 77,78 Hz |
| A | 110,00 Hz | 108,00 Hz | 103,83 Hz |
| D | 146,83 Hz | 144,16 Hz | 138,59 Hz |
| G | 195,99 Hz | 192,43 Hz | 185,00 Hz |
| B | 246,94 Hz | 242,45 Hz | 233,08 Hz |
| E (high) | 329,63 Hz | 323,63 Hz | 311,13 Hz |
The middle column is the first one times 432 divided by 440 — the same factor everywhere, 0.9818. The right-hand one is the first times the twelfth root of a semitone. Two different calculations, two different results, and that is why the two columns do not match.
How you actually tune to 432
Look for the reference pitch in your tuner. Almost every clip-on has it, usually labelled Calibration, A4 or Pitch. It comes set to 440.
Set it to 432. Usually with the same button you otherwise use to switch modes, held down. Eight steps down.
Now tune as usual. E, A, D, G, B, E — the device does the arithmetic for you. You only need the numbers above if your tuner has no reference pitch; then you type them into a tuning app.
You do not have to worry about the neck. 1.8 per cent less tension is a fraction of what one gauge lighter would do. With E♭ or lower it looks different.
And what about Hendrix?
The argument turns up in every other thread: Hendrix played at 432, that is why it sounds like that. The recordings really do sit lower than concert pitch — but by roughly a half step, which is about 100 cents. That is the left-hand column above, not the middle one.
Why he did it is no mystery: a half step less tension makes bending easier, and it suits the voice. It was common among guitarists of those years and has stayed common.
That he had 432 in mind while doing so — for that we know of no source, and the numbers argue against it. Between 432 and a half step down lie 68 cents. That is more than two thirds of a semitone; hear them side by side and you will not confuse them.
The real problem comes afterwards
Your guitar now sits at 432. The recording you want to play along with sits at 440 — and so things sound together that do not belong together. Either you tune back, or the recording comes to you.
That is exactly what the IYAMBAE Tuner is for: it shifts the sound on its way to the speaker without touching the tempo. What comes out of the computer then sits where your instrument sits.
One question remains worth asking: does the recording sit at 440 at all? Many do not — tape machines ran imprecisely, and whoever found a piano in the studio took its tuning. Drag the file into the measuring tool and you will know instead of assuming.