01
A note name needs an octave and a reference
The label D is incomplete for tuning because D3 and D4 are an octave apart. D4 has twice the target frequency of D3. A complete handpan note list should therefore include octave numbers as well as accidentals such as Bb or F#.
The reference pitch defines one anchor for the system. With A4 set to 440Hz, equal temperament calculates every semitone using a frequency ratio of 2 raised to the power of 1/12. With A4 set to 432Hz, the note names remain the same but all target frequencies move lower.
02
A tone field is not a pure sine wave
A tuned handpan field normally contains a fundamental plus prominent upper resonances associated with the octave and compound fifth. The shell, air cavity and neighboring fields also contribute energy, so a microphone receives a changing mixture rather than one isolated frequency.
Strike position and force affect which components are strongest. During the initial attack, a detector may follow an upper resonance; after the sound settles, the fundamental may become clearer. This is one reason a stable reading is more useful than the first number shown.
Fundamental
The main pitch used to name the tone field.
Octave
A strong mode near twice the fundamental frequency.
Fifth component
A tuned upper mode near three times the fundamental, heard as a compound fifth relationship.
03
Use frequency as one part of the check
Confirm the intended note list and A4 reference before measuring. Keep the microphone close enough for a clean signal without clipping, damp other ringing fields when practical, and compare several gentle strikes.
Frequency can show whether a stable component is above or below a target, but it does not describe the entire quality of the note. Sustain, beating, balance between partials and coupling with the shell still require careful listening and, when problems persist, professional assessment.
Try a measured check
Open the handpan tuner
Play one note at a time and wait for a stable reading.