Tine: Tuner and Metronome

Most tuners are guessing. Most metronomes are drifting. Tine does neither, and this describes exactly why. THE TUNER READS THE NOTE, NOT THE LOUDEST HARMONIC The easy way to build a tuner is to take an FFT and pick the loudest frequency. It fails twice on real instruments. A 4096-sample window has bins about 11 Hz apart, which down at the bottom of a guitar is most of a semitone - you cannot read cents off that. And on a low E string the second harmonic is routinely louder than the fundamental, so a peak-picking tuner reports the note an octave too high, confidently. Tine measures periodicity in the time domain instead. Across 222 test tones spanning B0 to C7 - pure sines, harmonically rich sawtooths, and plucked strings with a deliberately crippled fundamental - the worst error is 0.27 cents. That is roughly nineteen times finer than the 5-cent window in which it calls a note in tune.…