How many times a sound wave vibrates per second. Low numbers = bass you feel; high numbers = treble you hear as “sparkle.”
Hertz (Hz) is the unit for frequency — cycles per second. Humans generally hear from about 20Hz (felt more than heard) up to roughly 20,000Hz (20kHz), though that upper limit narrows with age.
Almost every spec on a measurement sheet is plotted against frequency: response curves, distortion, and impedance are all shown across the audible range. Learning to read the x-axis in Hz is the first step to reading any chart in your report.
| Context | Typical Home Audio | Typical Car Audio |
|---|---|---|
| Sub-bass | 20 – 60 Hz | 20 – 60 Hz |
| Midrange | 500 – 2,000 Hz | 500 – 2,000 Hz |
| Treble | 6,000 – 20,000 Hz | 6,000 – 20,000 Hz |
