Did anyone noticed a change in SQ after many Hours of listening ?
The truth about changes in sound in a headphone after some days/weeks/months is that, when is a real change that is proof with authentic measurements, this change is so, so, so small that your ears will not hearing the difference.
Why people often saying they hearing a difference in sound (always better, by the way!!) after days, weeks or months? This differences are principally psychological. Here I putting different variables that making people thinking the sound is better after some days/weeks/months:
1. Confirmation bias. People reading many times about (not proof!) positive effects of burn-in and they thinking this is true, so they saying now "Yes, now the sound is better than before!"
2. We don't always listening to music the same, this is identical with food, paintings, films, sex, etc. Sometimes we are more open / ready for listening to music, and others times we aren't. When we are 'desperate' for listening to music (maybe because is many hours or days of not doing this) even a cheap earphone or headphone is sounding great. We are hungry for music.
3. We don't always listening to music with the same volume --similar like we don't always eating so much or so little--, and usually when the music is more loud, we enjoying this music more. The difference in volume is affecting the frequency response too.
4. The time of the day when we are listening to music. If we hearing a lot of noise in the day, usually we are hearing the sounds of music differently more late in the day. Our ears maybe have 'enough' of loud sounds and music always isn't great after a busy day with loud sounds in our life around all day.
5. Something that is apparently silly but isn't. We don't responding the same always even to music that we know and like very much. The motivation for enjoying some music is depending in different factors, but this is other topic. For example, if we listening to something that we don't hearing for a long time, and we like this music, and we are in this mood, the music will sounding great. But, is more complex than this.
More variables are happening (like different positioning of a headphone in the head or small differences in earphone insertion or size and type of tips the person is using), but this is sufficient now. This variables not only explaining why we thinking the sound is better sometimes (always better, of course!), but more importantly, why we even saying / thinking that we are hearing more details in the music, better bass, more controlled bass/treble, better soundstage, etc.
Our auditory memory is really very, very poor, even from only few minutes when comparing one headphone/earphone to other.
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