As an example, these $50 headphones just released, co-designed by respected headphone reviewer Crinacle - he measures headphones on an expensive rig simulating the human ear, which can then be used to EQ the headphones to comply with a standard target response (typically, the "Harman curve").
These new headphones seem to comply stunningly well with that target curve. https://www.audiosciencereview.com/forum/index.php?threads/t...