Here are the GRAS measurements of the Sennheiser HD820. I’ve used a number of different targets, and I’ve tested channel matching on this unit. I’ve also added my EQ profile at the bottom for anyone who wants to get into EQ with this headphone.
L+R channel matching
HD820 Frequency Response vs my Harman Hybrid: Red = the averaged target, you can see positioning variation with the grey lines in the background
HD820 Frequency Response vs Harman 2013
HD 820 Frequency Response vs Harman 2018
HD 820 Frequency Response vs ‘Enthusiast Neutral’
Here’s my EQ profile:
I found that unfortunately the HD820 doesn’t respond quite as well to EQ as I would have liked, specifically in the upper mids around 3khz. Because of this, I ended up making my adjustment more conservative than I think I normally would on this one, just to avoid noticeable 2nd and 3rd harmonic issues creeping in.
Here’s the video of how and why I EQ the HD820 the way I did:
