This talk about kef m500's inspired me to write this ramble that has been long coming. I don't know where to post this but I think this is as good place as any. Many people new to headphone world come to this thread to seek for advice. That is understandable because chinese headphones often offer better value for money than other stuff.
With using kef as an example I try to explain why one should be very causious about other peoples opinions. I'll leave out obvious things like liking a certain soundsignature, what music one likes, how we all hear differently and other stuff like that.
1. Buying bias.
I bought B&w P7, M&D mh40, momentum 2.0, beats solo 2 and kef m500 to find my perfect portable headphones. Sennheiser got kicked out of the competition early because those were just not good enough by any standards. Beats, well... I kind of liked those. But I accidently broke those. Hideous build quality. I have owned about 150 headphones and those were first to self demolate on my hands. Hideous build quality. Not a big deal though, because those would have been ruled out by sound quality too but just wanted to say beats solo 2 are quite good sounding headphones.
Anyway, that leaves me with p7 and mh40 and kef m500. I honestly think thank m500 is the best headphone of those three. BUT i have a bias. I'm not made of money. Maybe I like m500 better because I wan't to sell mh40 and p7 because that would be the most affordable option? I got kids to feed...
It is a known fact that people tend to rank high headphones they have bought. Nobody want's to admit they've made a bad choice. I'ts just logical for human nature. That partially explains growing to like headphones and burn in. I won't comment on burn in any further but it sometimes has this aspect. This logically brings us to second bias.
2. Audition Bias
Before my quest for best portable headphones I auditioned oppo p3, focal pro and nad viso hp50. Short impressions I liked focal and hp50 but not p3. P3 was over twice as expensive. Later I have wondered did I dislike oppo for it's performance or for it's price. I't is common knowledge that it goes other way around too. Slap a $2000 price on a heapdhone and people think it is definately better than something that costs $300. Interesting thing is that I also auditioned He400i. Those cost about $499 back then. I did not like them much. Later I bought those for about $200 and completely fell in love with hifimans. I think those would have been a decent value even at $499. Now I think like that...now that I have not invested $500 for those.
3. Thread starter, discover new headphones, new toy syndrome bias
This is an important one. New toy syndrome is self explatanory. You get new headphones like them and rave about them being the best things since sliced bread. I't has happened to most of us
Things get more difficult if you have discovered a new heapdhone not known for public and even make a thread about those. This is where things get most weird. You hear people saying that $30 on ears sound as good as stax 009 etc.
They never do. I't is just a person who for some reason takes the headphones he/she discovered so personally and seriously that he/she starts to make absurd statement. Of course how we hear is subjective and I have no doubt one could actually hear cheap headphone X to be better than a $1000 headphones.
But seriously. I doubt there is a headphone manufacturer in a world that has so "bad" quality control that it would go unnoticed if they had accidently built a $30 headphone that sounds like $1000 headphones. And if they indeed built that they would instantly raise the price or sell the design to sennheiser, beyerdynamic etc. I'm not saying there aren't some awesome bang for the buck headphones around. Sure there are. But often if the head-fi review seems too good it propably is. And if you buy the headphones and like them that much too---> check buying bias
4. Gear bias
Well... like said I love kef m500. Compared to kef P7 has recessed mids, mh40's sound veiled and mikros90 too bright with small soundstage. Momentums just sounded dull in general. Does that make $200 kef a bargain because it (imo) is better than $399 p7 and mh40's? Well...kind of, and then not.
Most of my listening is done just by plugging headphones on my oneplus 3 phone. Kef is awesome with my phone but if I compare it to my fullsize headphones when amped...well, not so great. My modded msur m550's are a better headphone than m500's. But it takes amping. Moving on to jvc dx-1000 and kef sounds like shallow one dimensional headphone. It is not that of course, atleast not for it's price. But compared to a $1000 dx1000 with $2500 amp dac system it is just that.
Gear bias. That is extremely important to know where one comes from. I personally deem ones impressions wortheless if the person in question does not have experience of headphones of particular price range.
5. Other biases
Preferred soundsignatures, preferred music etc
EDIT: I left out ecpection bias because it involves most biases mentioned. Also I'm sorry about my language. I'm not a native engilsh speaker. Also I'm quite drunk, so that should why I post this thing in the first place.