A chart showing how loud a system plays across the audible spectrum — the single most-referenced measurement in any tuning report.
Frequency response is usually shown as a line graph: frequency (Hz) along the bottom, output level (dB) up the side. A perfectly flat line means equal output at every frequency; most real-world goals aim for a gently shaped curve rather than a ruler-flat one.
When reading a frequency response chart, focus on smoothness and the size of any peaks or dips rather than chasing perfect flatness. A single narrow dip of a few dB is rarely audible; a wide, several-dB peak across an octave usually is, and is the kind of thing room correction or EQ should target first.
| Context | Typical Home Audio | Typical Car Audio |
|---|---|---|
| Typical full-range goal | ±3 dB, 40 Hz–16 kHz | ±3 dB, 50 Hz–16 kHz |
| Subwoofer-only goal | ±3 dB, 20–80 Hz | ±3 dB, 25–80 Hz |
