Originally Posted by M-13
I hate to stir the pot, but wanted to add one more data point for people.
As a matter of personal opinion the HE-500 does have burn in. And 150 hours is just about right. I always said 120 minimum and after 200 no change ("stable")
This coming from someone who has his 4th pair of HE-500 and burning them in for the 4th time. I'm a big believer of the scientific method and a proud skeptic. But not everything shows up in Frequency Response Cuves/CSD/Impulse Response/Square Waves.
I think we need more sophisticated measuring tools and then we'll be able to measure small differences. Like being able to measure the diaphram with laser precision while real music is playing, instead of sending impulses to make measurements.
Now... saying all that can it just be a placebo psuedo effect and my brain is being fooled for the 4th time? Of course. Humans are faulty in general so why not.
I hope in the future we'll develope more sophisticated measuring tools to really flesh this issue out.
Well, to an extent headphones are a unique problem. In another thread, a recent test by Harmon international showed very different response curves by listener, some of which relating, for example, to the 'seal' between the phone and the head. So there can be variation in user to user experience, and also issues experianced by some but not all listeners. Or, in other words, finely crafted headphones are still likely to make very different impressions on every person that try them. For me, sound quality has been something 'learned', not necessarily known before hand. Yet I have always known that I like a more balanced presentation better than an un-balanced one, because the performance is usually more consistent across genres.
While I think burn-in is ultimately a major farce, I do think attitudes and preferences can adjust to new products. The "sporty" car you purchased on Monday may, after some months, seem quite tame compared to your memory of the initial driving experience. Some of this may be attributable to wear and tear, but not enough, IMHO, to really change the choice you made / would make now. Headphone diaphrams may break in somewhat, but are still working within certain mechanical tolerances.
Impressions and memory are not reliable sources of knowledge.