Here's an interesting question - how do you solve the problem of every pair of headphones and speakers in the world essentially sounding different? Sonarworks have been tackling this problem with their Reference sound calibation software, and at NAMM 2018 they gave us a demo of the latest version 4.
With more headphone models being added all the time, various pricing tiers are available depending on whether you need the software to run only in your DAW or system-wide for coping with things like Spotify listening.
Best suited for sound creation on headphones
Full package to work on headphones and speakers in your studio
Reference 4 Studio Edition and amazing pre-calibrated Sennheiser HD650 headphones