My first impression of HD820:
I was really curious about HD820, especially since I was not a big fan of HD800S, meaning that I was expecting much more from 800S than it delivered.
With HD820, this was an entirely different story. These headphones are the best closed headphones I ever heard...by far, and actually among the best of any type of headphones.
I compared to LCD-4Z, Sony MDR-Z1R, HD800, HD800S, ATH-ADX5000 and the only ones that managed to be in the same ball park was LCD-4Z.
When compared to HD800 but also with HD800S, they have better sub bass, better bass impact, the midrange is more present and *no harshness*. 820 has a better and more natural tonality. While HD800 still has a bigger soundstage and a little more details, I prefer HD820 by far. I think these are the HD800 done right.... just lovely...
Sennheiser did a great job with HD820!
Hopefully, I will be taking them for a full review soon. Can't stop thinking about them.
I listened to them from Hugo2 and ifi idsd pro.