Learn • Measurement Literacy
Read the graphs like the hobby's veterans do.
These are the same explainers behind every "?" tip on our graphs, scores, and calculators: short, sourced, and free of both marketing and gatekeeping. Ten minutes here makes every measurement on this site (and on squig.link) legible.
Reading measurements
What a frequency-response graph shows (and what it doesn't)
A frequency-response graph shows tonal balance (how loud each frequency plays), which drives most of how a headphone sounds. It does not directly show soundstage, imaging, or 'detail'.
Why 711 and B&K 5128 measurements can't be compared
Different measurement rigs (IEC 60318-4 '711' couplers vs the B&K 5128 head) have different ear geometries and resonances, so the same product graphs differently on each. Comparing curves across rigs is invalid.
What a 3 kHz peak (and other FR features) actually sounds like
Extra energy near 3 kHz sounds shouty and fatiguing on vocals; a dip there sounds distant or veiled. Learning a handful of these landmarks lets you 'hear' a graph before you buy.
The Harman target: what it is and what it isn't
The Harman target is a research-derived preference curve that most trained and untrained listeners rate highly, but it is a statistical average, not a law. Sizeable listener segments prefer more bass or less.
How to read qfiAudio's product scores
Our 0-10 scores are synthesized per listening axis from labeled, incentive-disclosed sources, and always published alongside the component axes, the sources, and any reviewer disagreement. There is no single blended 'overall' number.
Amps, sources & EQ
Sensitivity vs impedance: what actually makes headphones hard to drive
Sensitivity (dB per mW or per volt) sets how loud a headphone gets from a given output; impedance sets how much voltage vs current that takes. High impedance alone doesn't mean 'hard to drive'. Low sensitivity does.
Output impedance and damping: the Zout/8 rule
A source's output impedance should be at most 1/8 of the headphone's impedance. Above that, it audibly reshapes frequency response on multi-driver IEMs and loosens bass on low-impedance headphones.
Parametric EQ basics: filters, preamp, and clipping
Parametric EQ reshapes a headphone's frequency response with a handful of precise filters, the cheapest genuine sound upgrade in the hobby. Always apply negative preamp to offset boosts, or you'll clip.
Buying with clear eyes
Why aftermarket cables measure identical (and when they don't)
Competently made headphone cables of sane length measure identically and are indistinguishable in controlled listening. Buy cables for ergonomics, durability, and looks, not sound.
Unit variation and channel matching: the QC lottery
Two units of the same model can measure several dB apart, and left/right channels of one unit can mismatch audibly. A published graph describes one unit, and yours may differ.
Want to know how this site itself works (which sources we aggregate, how incentives are labeled, and how scores are computed)? That lives on the methodology page. To apply what you learn, open the graph tool or the power calculator.