The problem is that no matter how well you understand the technical aspects of a headphone and general sound, when you tell someone about a set of cans, you are giving your opinion. Whether your opinion is based on actually hearing the 'phones, or reading about them, it is still your opinion. "Objective" data cannot give a realistic understanding of how something actually sounds.
For example: the infamous ath-m50
according to it's frequency response graph (taken from both innerfidelity and headroom) it should be a fairly mid centric headphone.
However, anyone that has heard one could tell you that it's not.
Oh, and on a bit of a side note:
Here is a list of "facts" that I have garnered from several years of lurking around headfi.
1. Beats brand headphones are the worst thing ever made, anyone that says otherwise is an idiot and should probably be shot.
2. Bose headphones sound terrible. the only reason anyone buys them is because they have tricked into giving their money away based solely on name brand recognition. Bose is a
conspiracy crafted by the same guys that killed J.F.K.
3. On the eighth day, God made the ath-m50.
4. Bass is bad, you don't want it. If your head phones have any bass in them, you're probably just a "basshead" and don't have any appreciation for real music.
Unless you listen to dubstep,
then it's okay.
5. Skullcandy headphones are for children. Partially deaf children with no fashion sense.
6. If you own headphones manufactured by either Sennheiser, Grado or Audeze and you spent more than $600 on them, Guess what? You're better than everyone else!
7. If you haven't yet spent at least $20,000 on your set up,
(dac, tube amp, mahogany headphone stand, acoustically tiled listening room, and of course handmade planar magnetic headphones crafted out of agarwood cups with amur leopard skin
pads recabled with platinum coated oxygen free silver cables.)
Then you should consider upgrading immediately.