Why a CD takes 44,100 snapshots a second: Nyquist and the tone that folds back
30seconds
A CD stores music as 44,100 numbers a second, with nothing in between. Sample more than twice as fast as the highest pitch and the wave can be rebuilt exactly. Go past half the rate and the dots fold the tone back down into a different, lower note.
Drag a tone across the line in the interactive, then see why 44.1 kHz came from video tape and why phone calls sound dull.
Deep dive · 4 min
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