Originally Posted by luisdent
I used the pfe232 for months straight with no discernible difference in sound except that the silicon or foam tips would soften a bit after a while and the sound would get a little less bright. Once I used new tips again it was back to its original brightness. Plus, the signature is so different from the pfe112 that it would take a completely new earphone to bring it anywhere near the sound of the pfe112. I'm not saying you're not hearing a difference, and you may prefer it, but you would have to flatten the bass and treble by such a large amount you wouldn't get much close to flat no matter how much it might burn in. In other words, an earphone can't magically morph into another earphone with burn in. You can't buy a westone 4 and have it burn in until it sounds like the er4s. :-P There's about the same difference between the two. :-P
I personally don't believe in "driver" burn in. Tips, yes. But it is generally accepted that even if something did have "driver" burn in, it wouldn't be a large difference in sound. So at most, I'm guessing it is soothing the treble for you and maybe tightening the bass? Even if that's the case, the levels are still way to boosted for me personally. I prefer flat neutral sound.
Then again - you couldn't measure burn in as you were using it whilst it was burning in. With the exact same fit, exact same tips, same songs, same source (all invariant) I tested the 112 against the 232 and the treble was definitely sharper on the latter. After a long burn in of three weeks for the 232, the duration of which I used neither of these headphones at all, I put both on the exact same setup and the treble had swung. The 112 were definitely sharper than the 232.
I have seen thousands of posts on headfi on burn in, thousands of claims of 'brain based' burn in/no burn in, yet very very few measure it like me. Maybe I'm doing it wrong, but as far as I can tell it's the only way to get close to saying something objective about this phenomenon; compare it to something that is invariant.
I'm just talking about the treble here - there were plenty of other differences.
The pfe112 with grey filters is not flat in my opinion. It definitely has weaker than neutral bass, but that's not a bad thing. Music that has plenty of bass, even pristine live recordings where I've been in the audience, can't be reproduced faithfully in the bass regions by the 112. Impact, extension, weight, magnitude and decay are often lacking though not by much. Go to a headphone like the ultrasone sig pro / mad dog alpha / beyer t1 / phonak 232 and this bass line comes alive. I find the 112 perfectly enjoyable all round and this 'weakness' in bass is not a general weakness of the headphone. It's not something like the fischer dba02 which is outright flawed because of the lack of bass.