Sound
Harman target
Also called Harman curve, Harman tuning
The Harman target is a headphone frequency response curve derived from listener preference research at Harman International, with a moderate bass shelf and slightly less treble than the diffuse-field curve. Many headphones and IEMs are tuned toward it, and many measurement sites compare against it.
Sean Olive and colleagues started from the response a good loudspeaker produces at a listener’s ears in a good room, then ran preference tests in which trained and untrained listeners adjusted bass and treble levels. Separate curves exist for over-ear headphones and for in-ear monitors, and both have been revised since the first versions.
The research found that most listeners preferred a response resembling a good loudspeaker in a good room, which is where the bass lift comes from. It also found a minority who preferred more or less bass, so the target is an average, not a rule, and listeners disagree about it.
On audiophila., reviewers sometimes describe a tuning as "Harman-ish" when it follows the curve loosely. A product can match the target and still differ in Resolution, Dynamics or Soundstage, which the curve does not describe.