The shell
It all starts with two steel shells: a top shell that will hold the notes and a bottom shell.
They can be shaped using several methods, including press forming, hydroforming, metal spinning, and hammering. The aim is the same: to create a carefully shaped shell in which the different vibrating areas can then be formed.
The type of steel also affects how the instrument behaves. Nitrided steel and stainless steel respond differently to shaping, tuning, and playing.
The tone fields
The notes on a handpan are neither strings nor tongues cut into the metal. They are shaped directly into the shell.
Each tone field is given a specific shape and tension so it vibrates at the intended pitch when struck. The central dome, known as the ding, is also a tuned area.
This work on the shape and tension of the steel gradually turns a simple metal shell into an instrument.
Tuning
A handpan note generally contains more than a single frequency.
On many instruments, the main note, known as the fundamental, is accompanied by two tuned harmonics: the octave and the fifth above the octave. Together, they contribute to the richness and character of each note.
Tuning develops gradually through a series of small adjustments to the shape and tension of the metal. Listening is supported by frequency analysis tools that allow the behavior of each tone field to be checked precisely.
Because all the notes share the same shell, they are never entirely independent. Some may resonate slightly with one another. When this interaction remains harmonious and controlled, it contributes to the instrument's character. Tuning aims primarily to limit resonances that are dissonant or too prominent.
Assembly and resonance
Once the two shells are ready, they are joined at the rim. Together, they form a resonant cavity that plays an integral role in the handpan's sound.
The opening on the underside of the instrument, known as the gu, allows the air inside this cavity to resonate. Its shape, the volume of the shell, and the instrument's notes all interact to shape the final sound.
Assembly can slightly alter how the notes behave. The tuning is therefore checked again once the instrument is closed and can be adjusted further until the desired balance is achieved.
Steel and finish
The type of steel affects more than the handpan's appearance.
Nitrided steel is steel whose surface has been treated by diffusing nitrogen into it. This treatment increases its hardness and improves its resistance to corrosion compared with untreated steel. It is often associated with a more immediate response and shorter sustain.
Stainless steel naturally offers greater resistance to corrosion and often has longer sustain, with notes that continue to ring longer after being struck.
These are general tendencies, however, and do not make one type of steel better than the other. The quality of the shaping and tuning remains essential: two handpans made from the same type of steel can have very different characters.
Understanding the specifications
Specifications help you understand what an instrument offers before you even hear it.
The scale and exact list of notes give you a sense of its musical character. The note layout shows which notes are on the top and which are on the underside. The number of notes gives an indication of the available range, while the tuning reference, usually 432 or 440 Hz, tells you the standard used to tune the instrument as a whole.
The type of steel also provides clues about sustain, care, and the instrument's overall response. Dimensions and weight help you understand how it will feel to hold and carry.
These details are useful when comparing two handpans, but they do not tell the whole story about sound quality. Specifications describe the instrument; listening tells you how it sounds.