https://www.head-fi.org/threads/sennheiser-...7#post-13937885

And there ya go for those who kept droning on about the 800S “distortion”.
Have mentioned before, but I’ve never heard the distortion, and neither did others until they read Tyll’s review.
And just like Head-fi, many did not even hear the 800S before jumping the gun fanning the distortion rumour instead of using their own ears to listen.

Yep I did. Mostly it’s those who insist there is hardly any distortion heard and those who say they hear it. In the end I’d still say it’s listen with your own ears instead of jumping the gun believing reviews or measurements even if it’s from Tyll or Jude lol.
The only measurement I actually look at is the FR chart just to roughly get an idea of the sound signature. But even then I only give the chart a 50% serious attention.
But Axel did confirm that they did not intentionally do anything to add any distortion.