@Brooko The issue I have with brain burn-in is that we will get used to essentially any headphone, no matter the flaws, over enough time. Does it mean the headphone is good? Maybe not, but our brains got used to the sound signature all the same. So then it seems that a review is unnecessary altogether - since at the end of the day a customer will be fine with it in the long run. I'd say that the newest gear is not the one we know the least, but the most - since our brains haven't compensated yet for the flaws it may have.
But I agree completely with the Dunu comment. Although I kept the review the same for build quality, comfort, isolation (that varied a bit for me, actually), etc., when it came to sound they could have been from two different companies, for all I know. Th worst type of review (and the one that actually applied to a DUNU review), is reviewing a headphone and not covering a sound section. Like... that's the most important part of the headphone...
I'm not brooko but I thought I would chime in.
In regards to the brain burn in, I think, the "getting" use to part of it maybe misleading.
from my perspective I find the "getting use to part" is more so giving it a chance so to speak, because for example and bear with me here
if I was say using my hifiman re400 (which could be considered as very balanced with a hint of warmth), which caters to a different kind of sound and audience compare to lets say I review the Nuforce NE800M (which is much bassier and much warmer in comparison).
then I jump to say the Dunu Titan 5 (which is a bit more on the bassier side> re400, but brighter sounding then the ne800M)
in all three scenarios you have three earphones that have different sound signatures and if you were to enjoy the hifiman re400 (which I really do),
then jump toward the nuforce ne800M, you could immediately tell there is a such a thick lower mids area that would impact its speed and clarity for bass notes compared to the leaner re400.
and then jumping immediately to the dunu titan 5, you would find the titan 5 overly bright compared to the very smooth, chocolately ne800M.
if you were to base your reviews on those initial impressions alone then I feel it might not be as indicative of the overall presentation of its sound.
why is that?
because its unlikely that someone were to come from the same direction in terms of "earphone-jumping" as you.
I think those interested in a more bassier sound, the ne800M would appeal to them more so, and they may never even consider the hifiman re400 for example. and if they were to see that I said that the ne800M sounds slower RELATIVE to the hifiman 400 (that would be accurate). but evaluating the ne800M based on what it is,
a bassy, smooth sound, that would require a bit more adjustment for the brain (at least for me) and then I can properly evaluate it based on its merits for its "target sound" and "target audience".
similarly, the dunu titan 5 is a on the brighter end and some users may not even look at the nuforce ne800M (because its a lot smoother overall), maybe too smooth for some, maybe to the point of being muffled to some.
I feel like its a period that helps "reset your brain" and ears so to speak.
and I don't think if something say sounds terrible at first listen, and after many weeks. (it still sounds terrible, and you may get use to it in a sense (because you spend $X amount of money on it, but that doesn't change the fact that your not satisfied.