Oh man, what a revelation, thanks for the tip!
. My HD650 is well burned in (10 years old, mainly used to casual listening) and I have been working with it for a while now. What strikes me most looking at the graph is how different left and right are, not to mention the drop and peak before/after 10k. This is obviously very different form their “averages”. Hence, if you get Sonarworks, you must go with their custom calibration. Who buys a sports car and saves on the engine?