[prone2phone]

there are apps for smartphones that measure noise in decibels, for example SoundMeter , (i also had similar for symbian phones).

and when you have new headphones, just put them close to iphone's microphone and play some test tones (for example 30hz,40hz,1khz...), write down db figures from your app. then repeat precisely the same thing after some time (for examlpe 100 hours).

if there is significant difference between db scores - physical burn in exists.

 

[Postal_Blue]

The concept is sound, I would not however consider doing the "experiment" with anything short of a dedicated SPL meter.

 

[revolink24]

Agreed. That microphone isn't exactly quality.

I've done some tests with a standard LDC microphone, and didn't find much of anything conclusive.If there are changes, I doubt they're really in the frequency response curve.

 

[El_Doug]

unless youre doing this in a sound proof environment, and also with EXTREME precision have the headphones the same distance/position from the mic, you will always get different results, even with a professional meter

 

[MASantos]

Burn in of speakers and headphones is real and pretty much accepted as such by the majority of people. The characteristics of physical components of the drivers (voice coil, rubber, etc) change with movement and "adjust" to each other and make small or big changes in sound.

The big discussion about burn in is about passive components like resistors or capacitors and the like.

I also agree that your test methodology is to say the least, very simple and can't yield consistent results to be accepted as "proof" of burn in.

 

[Uncle Erik]

Quote:

Originally Posted by MASantos /img/forum/go_quote.gif Burn in of speakers and headphones is real and pretty much accepted as such by the majority of people. The characteristics of physical components of the drivers (voice coil, rubber, etc) change with movement and "adjust" to each other and make small or big changes in sound. The big discussion about burn in is about passive components like resistors or capacitors and the like.

Do you know of any test measurements or scientific papers that support this opinion? This is one of those things that sounds plausible but has never, to my knowledge, been demonstrated with audio equipment. If actual, physical, changes take place, they should be demonstrable, measureable and repeatable.

Actually, capacitors do break in, or "form up." This happens in under a second when power is first applied to them.

 

[nikongod]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Do you know of any test measurements or scientific papers that support this opinion? This is one of those things that sounds plausible but has never, to my knowledge, been demonstrated with audio equipment. If actual, physical, changes take place, they should be demonstrable, measureable and repeatable.

Here are 2 posts from an older thread that have VERY useful links to evidence demonstrating burn in in large woofer drivers.

link

second link

Before the whole "but those are woofers" argument comes out, measuring TS parameters on smaller drivers is beyond the abilities of many people.

Would anyone be willing to go halves with me on a burn-in experiment on KSC-75 (or some other decent but cheap headphones)? Id keep 1 as control to be tested for as little time as possible, and burn one in, testing as frequently as I could be bothered (every 2 days or so) posting my findings in graphs from a VERY cheap measurement system (the RTA on my behringer DEQ playing noise...) in a blog.

 

[luvdunhill]

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif measuring TS parameters on smaller drivers is beyond the abilities of many people

depends how small, but I'm assuming you mean headphone drivers.

delta mass method would be difficult, agreed. delta compliance method, probably easier, but again, headphone drivers aren't usually mounted in a box. Ari, have you ever used Speaker Workshop?

 

[nikongod]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif depends how small, but I'm assuming you mean headphone drivers.

yes, I meant sub 2" drivers.
Quote:

delta mass method would be difficult, agreed. delta compliance method, probably easier, but again, headphone drivers aren't usually mounted in a box. Ari, have you ever used Speaker Workshop?

No, I have not.

 

[prone2phone]

maybe for measuring cables' burn in one needs NASA equipment, but for dynamic headphones iphone should be enough - many respectable reviewers hear the change even by their ears...

 

[chesterqw]

Quote:

Originally Posted by prone2phone /img/forum/go_quote.gif maybe for measuring cables' burn in one needs NASA equipment, but for dynamic headphones iphone should be enough - many respectable reviewers hear the change even by their ears...

do you know how powerful human ears are?