Bought the AGV k3 the other day and above 30mph the wind noise is absolutely unbearable. I'm on a sport touring bike (xj6-f diversion) with an aftermarket windshield, I even tried taking off the windshield in case that was the issue but it's the same.
The sun visor can be heard rattling around inside the helmet when wearing it and the wind noise is absolutely deafening when you're going 50+, even with earplugs in.
My friends were all connected on cardos and i couldn't hear anything unless I full tucked in below the windshield. I tried various combinations of vent settings, visor locked or cracked, everything. This is the new ECE2206 version too so you'd think they would have sorted the noise issues out.
I had an AGV K1 before this, which people always complain about wind noise for but that helmet is a million times quieter than this at any speed. I'm going to try and return the helmet if I can, but stay away if you are considering it - genuinely the worst riding experience on a motorway I've ever had.