it's great project. No idea why some people do not want to eq their headphones at least a little bit. It can make a huge difference. Also frequency response is IMHO at least partially a matter of taste.
Taste, yes; and individual circumstances. My hearing is so good it might count as a disability, but I know where I have peaks and valleys in my sensitivity and a good EQ can help with the spikes taken by tinnitus ringing from youthful big boom car stereo work and explosives.
I checked their suggestions for my headphones against my EQ profile and theirs is pretty good. I like more lowfreq and much less high freq than the "flat" they're correcting for.
They're offering a great resource for skipping the "what does this set of cans sound like" stage. I probably spent 60hr or more dialing these in when i got them.
I don't hear "notes" and "chords", I hear frequencies. My range (at near 50) still goes up to where i can hear the bats talking. In a room with people, i cannot not hear their pulse, breathing, and other biological proceedings...
Oh WOW, that is ...... wild and interesting
As far as I know it's more of a brain thing and not like a super-ear thing.
some professional audio engineers have some special recordings they listen to on everything and use a faith based or at least difficult to quantify internal process to come up with the "right" sound. I'm more in that end of the spectrum.
Edit: I stand corrected, as the poster below mention (I can't reply), I'd want an audiogram from a professional. Thanks!
There's also no way to apply a system wide eq to an iPhone, so you'll need an external device.
Granted my home speakers might have something to do with it, and headphones/earbuds do tend to have a high-pass filter built in just from their construction, so it probably doesn't affect everyone the same way.
I've been using equalizerAPO for desktop for years. I can only think of a handful of content creators that don't pull that bass-boosting garbage anymore, so the high-pass filter pretty much always stays on unless I'm playing music.