I made this account just to say THANK YOU!! to 01890jp and Robbo - this low shelf +3db at 75 freq with -3 preamp is the greatest thing for this HD600. I admit I haven't tried a lot of EQ's with these headphones, but I like this so much more than Oratory. Even Oratory I think on a YouTube video I saw mentioned he wouldn't add an EQ to these headphones because it ruins the sound basically. But this low shelf just makes the bass better, and keeps the headphones sounding amazing. I totally agree with 01890jp that this basically makes the headphones incredible. I want to thank 01890jp for having the idea to begin with and Robbo for putting in the extra effort to get it perfect. You two are legends to me. This is awesome! I feel like everyone that has these headphones needs to try this. To the point where Oratory should add this as an optional set up as this is the perfect conservative fix.