You can search measurements of your headphones by serial number here.
To open the file you'll need a freeware software REW that you can get here.
All measurements use a compensation curve to better represent human ear sensitivity.
HUR ÄR DE I JÄMFÖRELSE
OLLO vs. Sennheiser vs. Audeze vs. AKG vs. Beyerdynamics vs. Audio Technica
We measured and compare the frequency responses of the main mixing headphones on the market. Measurements were made using G.R.A.S 45CC using IEC 60318-1 ear simulator and Dewesoft AD conversion Sirius system.