Brubaker
New Head-Fier
I'll answer to myself. Here are the InnerFidelity (Jaako Pasanen) PEQ parameters for the Nighthawk :
https://github.com/jaakkopasanen/AutoEq/tree/master/results/innerfidelity/innerfidelity_harman_over-ear_2018/AudioQuest NightHawk
You could keep it simple and try a setting like low shelf at 800Hz, -4db, Q=1 and peak at 7000Hz, -4db, Q2.5