How to tune a handpan
A handpan is not tuned like a guitar. Each area of the shell produces several sounds at once, and it is their relationship that gives the note its character. Correcting them means understanding what you measure before knowing where to strike.
What happens inside a note
Strike a note: you hear one pitch. The steel produces several at once.
The fundamental is the pitch you perceive, the one that gives the note its name.
The octave sounds at twice that frequency. It is deliberately hammered into the area; it does not appear on its own.
The fifth sounds at three times, an octave above the just fifth. It is the third partial makers tune.
Other frequencies exist, which makers often call shoulder tones.
An ordinary chromatic tuner shows one pitch at a time. It is of little use here.
Why a handpan drifts out of tune
Steel moves over time. That is its nature, and it depends on the quality of the metal and on how carefully it was stabilised during making.
Time. The tensions introduced during forming release slowly. A well-stabilised instrument moves less than another.
Temperature and humidity. Metal reacts to its surroundings, and these variations play their part in the drift.
Knocks. A fall, a heavy object left on top: a few tenths of a millimetre of deformation in the metal are enough to move a partial.
The three partials of a note do not necessarily move together. A fundamental can stay in tune while its octave has slipped — which is why it is better to measure them separately.
What to measure before touching a hammer
Measuring costs nothing and risks nothing. It is the part anyone can do.
The three partials of each note, with their deviation in cents from the target. That is the state of things.
Stability over time. A note can show the right value at the attack and drift while it rings. What it does across the whole sound is important information.
The secondary frequencies. They are read on a spectrogram, placed by their ratio to the fundamental — ×2, ×3, ×9 and beyond.
The reference pitch. Most instruments are tuned with A at 440 Hz, some at 432. Measuring against the wrong reference throws everything off.
The gesture
This is where this text stops, deliberately.
Correcting a partial means striking the steel at a precise place, with a precise force, in a precise direction. These three things are learnt under the hand of someone who already tunes. No written description conveys them.
What makes the exercise difficult is not knowing where to strike: it is that working one area to adjust a partial can move the others. Tuning a handpan often means seeking a balance between values that are linked to each other, note after note.
Should you do it yourself?
Measuring, yes. It is useful to know where the instrument stands, to decide whether it needs servicing, or to check that a tuning has held.
Correcting, no — not without training. A misplaced blow can deform the area irreversibly. A damaged instrument costs more to repair than a tuning.
If your measurements show a drift that bothers you, contact a tuner. Your records will probably save them time: they will know a little better what to expect.
Frequently asked questions
Do you need a special microphone? A phone or computer microphone is already enough to measure. A good external microphone remains better suited to capture the widest range of frequencies.
How often should you check? There is no rule. Generally, a retuning happens every one to three years, but it depends on the instrument and the use. An occasional measurement gives an idea of how things are changing.
440 or 432 Hz? 440 Hz is the international reference, and the great majority of instruments are tuned to it. Some prefer 432 Hz, a slightly lower reference. What matters is measuring against the instrument's own reference.
How long does a full tuning take? Measuring is quick: a few seconds per note when the three partials appear together. Correcting is the work of a trained tuner and takes longer.