Headphones AutoEq
Headphones aren’t a frequent visitor to my skull, when mixing or producing (other than to check things like stereo width, low frequency response..) but some folks don’t have the space/funds to set up decent monitors to mix or produce with, and have no choice but to use headphones. And that’s fine! We can only use what we have access to. And we learn to make the best of it.
But headphones, like speakers/monitors, have a sonic signature developed by the manufacturers, and until you have learned to ‘hear around it’, it will be colouring the sound, and possibly affecting the decisions you’re making to improve the sound.
The problem has already been identified by a number of companies including SonarWorks (also for monitors and rooms), ToneBoosters Morphit, dSONIQ (also adds “Virtual acoustic spaces” to mix in) and Waves have their one too but I choose to openly recommend them.
On the other hand there is an open source project currently running which is gathering the frequency signatures of as many headphones as possible, and providing this data for people to put in their own EQ to reshape the headphone sound.
It is called AutoEQ, and if you are restricted to headphones, or regularly require them, this is a lot cheaper than the products listed above; it is free.