Yes it happened to me once, that's why I asked, is it wrong to ask such question when you doubt something at first sight? I'd rather double check. Now that I personally own NDH 20, that distortion peak just surprises me, ehm. It's even more funny because even the studio pros I know and Neumann guys say praises about these headphones, with regards to resonances, extremely low distortion, etc. At least in my experience, the drivers in these headphones are fast settling and bass distortion sounds mostly even-harmonic to me, which can be a normal thing at proper SPLs. But I would definitely want to hear Neumann's take on these ASR measurements.