Headphones

Every headphone error is either stable or unstable#

Conclusion first: it's better not to use corrective EQ on headphones. Here's why.

Every error a headphone makes at your ear is either stable or unstable. Stable means it's the same, within what you can hear, every time you put it on. Unstable means it audibly changes with the seating and with the seal of the cups. Even opening your mouth might change it slightly. If you shove a mic in the cup, play white noise, move it about and watch an analyser, you'll see the peaks and troughs move.

EQ cannot track an error that moves#

So you measure your headphones and cut the peaks. Then you move them on your head. The EQ stays put and the peaks shift. In the worst case it now boosts a peak and cuts a trough, making things worse. You can't EQ something that moves about.

Correction targets an average ear that does not exist#

EQ can't fully fix stable errors either. Whose ear are you correcting for? Your outer ear changes how headphones sound to you, by quite a lot. The measurements come from a dummy head with rubber ears that aren't yours, placed in an average position and averaged over a few seatings. The target curves are averages of many listeners' preferences. Averages on top of averages.

No living pair of ears matches it. Correcting to it treats an abstraction as if it were a real member of the group, which is what Gilbert Ryle would call a category mistake. A perfectly accurate headphone is impossible for the same reason: the driver sits right next to your eardrum, and everyone's ears are shaped differently.

You have to learn your headphones either way#

If you EQ towards the target, there's still a gap between that average ear and yours, which your brain has to learn. And if you just EQ in a bit more bass, now you have to learn the headphones with the EQ. With or without EQ, you learn.

The point of accuracy is better decisions. Once you've minimised the unstable errors and learned the stable ones, your decisions are already right and there's nothing left for EQ to correct. The trade-off with headphones that minimise the unstable errors is that they're often bass-shy. I just learn that, the same way professionals learn to mix on NS10s.

Every addition to the monitoring chain has a cost#

Nothing in a monitoring chain has zero chance of failing, of not being there when you need it, or of user error.

My reference headphones#

The Sennheiser HD600/650/660S family was my reference for over a decade and is still top tier. The HEDD D1 is now my daily main pair, and it's only slightly better: a bit clearer in the highs, with deeper bass extension and lower bass distortion, which is not the same as more bass. The D1 has low enough bass distortion to take a bit of bass EQ, where the HD600s start to distort. I don't EQ my headphones. If you already own HD600s, I wouldn't go and buy D1s.

Disclosure: I asked HEDD for a review pair on the condition that I'd send them back if I didn't like them. I kept them in exchange for the review. No money changed hands.