There is absolutely no objective standard test for anything in this hobby. Everything is subjective... even stuff that sounds objective is usually either taken out of context or overstating the importance of certain measurements that do not have that big of an effect in real life. You will learn soon enough that most people here form their opinions first, and then cherry-pick information to support their view. If you have come for objective-talk, this website is probably not the best place for you.
There is the frequency response curve serves as a rough guideline on how to expect headphones to sound overall. There is harmonic distortion curves, square wave response, and cumulative spectral decay (waterfall) plots/impulse response. I am not sure how valuable any of these objective measurements are. I am actually in the pro-measurements/objectivity camp, but it doesn't seem like any of those measurements really means much in real life applications except the frequency response curve. Everything else seems kinda just bragging rights that it measured well.
However, I think there is actually a lot of value in an ear test. If you have ears (no need for special ears), and just do a double blind ABx comparison between two headphones that you have done no research about in terms of price/reviewed performance... I think whatever the difference you hear would probably be pretty accurate (as after you remove expectation bias, our ears are quite good at picking random differences).
In fact, I honestly think that the lack of objective criteria is one of the reasons some people are drawn to this hobby. They like the fact that you can be a "golden ear/audiophile" and sound like a really legit expert without really saying/knowing anything beyond owning something expensive. The fact that there isn't a comprehensive sticky about common audiophile myths & what current scientific testing has found (cable difference, burn-in, decay, the real-world impact of amps/dacs) and the fact that head-fi is actually ad-sponsored... I really think that the main purpose of this website is really just to promote purchasing 'audiophile' gear and for people who enjoy the gear to socialize. Questioning sketchy manufacturer practices like charging an additional >$100+ for a small tweak for essentially the same product doesn't really get anywhere around here. Questioning price
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
erformance ratio usually just piss off owners of expensive stuff. Anytime you try to get into any objective type debate on the general forums, any random person's subjective impressions is always "more legit" due to the head-fi mentality that statements about headphones are only valid after hearing them.
Just what I've found from my experiences here. Didn't mean to sound negative about this place, but I think you have to see this website for what it is: bunch of headphone geeks that are using it as a platform to express their opinions and have people listen to them as audiophile experts.