Frequency Response Graphs

The frequency response graph is the most important visual in audio. Everything else is secondary.

[VISUAL PLACEHOLDER: FrequencyResponseReading_Guide.png] Description: Annotated frequency response graph with: X-axis labels at 20 Hz, 100 Hz, 1 kHz, 10 kHz, 20 kHz; Y-axis labels at -20, -10, 0, +10, +20 dB; callouts pointing to a peak at 80 Hz labeled "cabin resonance +8 dB", a dip at 250 Hz labeled "crossover transition -6 dB", and a broad rolloff above 12 kHz labeled "tweeter natural rolloff"

X-axis (horizontal): Frequency

Always logarithmic — each decade (10× increase) takes the same horizontal space. This matches human hearing, which is logarithmic: we hear equal steps between octaves, not equal steps between Hz values.

Left edge = 20 Hz (lowest audible bass) Right edge = 20,000 Hz (highest audible treble) Middle of graph ≈ 1,000 Hz (midrange)

Y-axis (vertical): Level in dB

0 dB = reference (usually the average level of the curve) Positive dB = louder than reference Negative dB = quieter than reference

Scale matters: A graph with ±30 dB scale looks very different from the same data on a ±10 dB scale. Always check the scale before judging how flat or uneven a response looks.

[VISUAL PLACEHOLDER: SameResponseDifferent_Scales.png] Description: Same frequency response curve plotted on three different Y-axis scales: ±30 dB (looks flat), ±10 dB (looks moderate), ±5 dB (looks extreme) — illustrating why scale matters

Common features to identify: