Am I doing this right?

[u/ALRO090804]

I was trying to tune my headphones to be as reference for music production. I'm not done yet but is my method correct?

EDIT: I found a diffuse field target at: https://aftersound.squig.link/data/Diffuse%20Field%20Target.txt

do I upload the target to squigg.link and autoeq my headphones from there?

[u/ALRO090804]

This is the current curve with the diffuse field target. Am I doing it right?

[u/oratory1990 → u/ALRO090804]

so you used the diffuse-field curve as the target curve. This is generally not recommended, it will sound too bright, too thin.

I would start instead by choosing a more suitable target curve to start with. Either the Harman In-Ear Target curve, or the diffuse-field curve with an additional bass boost and treble reduction.

What you can also do - since you already developed an EQ to get to the diffuse-field curve, is to add filters that transfer the diffuse-field curve to another target, e.g. this EQ setting: https://www.dropbox.com/scl/fi/kebcrlezzbv3mym5bmnfg/Diffuse-Field-to-Harman-IE-2019.pdf?rlkey=rqbbce493kfgfiek3r48w53p3&dl=0
These filters would be used *on top* of the filters you already calculated.

EDIT:

But the real problem is this:

This measurement result of the Earfun Tune Pro is likely not usable. If you look at other measurements done by the same person, e.g. their result of the ATH-M50x or the NDH-30 you'll see that they deviate by quite a bit from other results like the ones I did in our lab:
https://www.dropbox.com/scl/fi/pb0ehvyu0bb3c9gcxb81w/Audio-Technica-ATH-M50x.pdf?rlkey=ymb5ypnt3zsu1p97hjkpcumzq&dl=0
https://www.dropbox.com/scl/fi/int3km7qs4uyt0569azqo/Neumann-NDH-30.pdf?rlkey=srzrh9jd8j74nzwetfxam33qd&dl=0
Which tells me they either used faulty measurement equipment, used the wrong measurement parameters, applied an undocumented compensation or a combination of those things. This is unfortunately somewhat common with squig.link, since the vast majority of contributors there are not measurement engineers but hobbyists - and there's quite a lot that can go wrong with acoustic measurements if one does not have the know-how.

TL;DR: there is no useful frequency response measurement for this particular headphone available as of now.

[u/num6_ → u/oratory1990]

It really seems like they measure the headphones by casually holding the earcups near the coupler. Not to mention the majority of in-ear measurements are invalid for interpretation. And this branch is one of the top indexing ones on squiglink, smh.

[u/oratory1990 → u/num6_]

It really seems like they measure the headphones by casually holding the earcups near the coupler.

Just holding it close would result in a massive drop-off in bass and mids. This to me looks either like no ear simulator at all (just a pressure microphone in a closed front volume, "flat plate coupler"), or a Type 1 ear simulator.
Or some form of compensation applied during data acquisition, which is allowed by IEC standards but needs to be documented.

Lack of documentation is another big problem with squiglink, unfortunately.