Okay I don't know what the ever loving hell is going on here. Set 1 Set 2 First set of measurements I took in May of this year, latter set earlier today. Both are averages of multiple positions on the EARS rig, and both use the same MiniDSP stock HEQ curve— I junked the custom one I was working on because I was losing the forest for the trees and spending too much time fixating on individual frequencies, felt it'd be more beneficial to practise taking consistent measurements for the meantime. Results in latter case are repeatable. I know I've said before that I've seldom thought the DT880s fatiguing, but I was perfectly happy to accept the notion that my ears might have gotten royally bjork-ed; the first set of measurements would support that theory with its broad, 7dB over 1kHz ~8.5kHz spike. On the other hand the latter set looks closer to what I'd have guessed if I didn't know offhand that Beyer had a reputation for treble spikes— subjective impressions listening now are bloomy bass and nice, level midrange with crappy extension on either extremity, actually kinda dull at the uppermost octave, no notable sibilance, at least relative to the HP-3 or TH-X00EB. I do believe that burn in could explain this, but if that's the case then y'all better be running your DT880s 24/7 for at least a full year before expecting any changes because I'm the fourth owner of this particular set and these might have been around since before I even got into audio. Notable is the fact that Set 2 has the weird 4kHz dip that definitely looks like a measurement artifact. P.S. Yes this is my second thread today, sorry, just figured it'd make more sense than packaging both sets of measurements together.