We are now wading into scientific territory because the psychoacoustics, or the study of how people respond to sound signatures, that gave rise to the Harman Curve, is what makes it possible. Have you ever wondered why there isn’t a signature that everyone finds appealing? Why does each speaker have a distinctive voice?

The mystery of what tuning appeals to human ears the best was investigated in 2010 by Sean Olive (Harman International) and his colleagues. They put hundreds of headphones on the test on thousands of listeners from around the world. They finally develop the Harman Curve.

HOW DOES IT SOUND?

The Harman curve is a theoretical target sound signature said to produce the best sound quality that most but all listeners would prefer.

The Harman Curve is essentially a specific target frequency response that produces the “best possible sound” for headphones.

Frequency response refers to the range of bass, mids, and treble that headphones can reproduce. The ideal frequency range covers the audible sound range of 20Hz–20kHz.

Harman target curve usually has a boosted sub-bass, neutral to "slightly above neutral" mid-bass, flat mids, slight above flat upper mids and extended treble response.

Harman target curve was developed to mimic the speakers-like sound quality in a headphones form factor.