ATH-M20x
headphones
$59
Used market: $45*
Specifications
2 of 7 values have a recorded sourceExpert Audio Engineering Commentary
Tonal Profile
The cheapest headphone in this catalogue and the one whose numbers are hardest to pin down, because Audio-Technica publishes them with the unit in Japan and without it in the United States. 96 dB/mW at 47 Ohms works out to roughly 110 dB from 0.55 V — comfortably within a laptop jack. Fixed cable, no folding, no adapter thread: built to be replaced, not serviced.
What the datasheet actually says
Quoted verbatim from the manufacturer’s own page, with the date we checked it. We state what is printed, not what anyone intended by it.
«Sensitivity 96 dB»
Audio-Technica's US page for the ATH-M20x and ATH-M30x prints the sensitivity without a unit, while the same company's pages for the ATH-M60x («102 dB/mW»), ATH-AD500X («100dB/mW») and ATH-AD700X («100 dB/mW») name it, and Audio-Technica's own Japanese site prints «96dB/mW» for these very models. So the number is per milliwatt. Read as dB/V instead, a 47 Ohm headphone would appear 13 dB more sensitive than it is, and the M-series would look like it needs almost no amplifier at all.
checked 8/5/2026* Estimated with the depreciation fallback (~76% retained value). · checked on 8/5/2026