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My theory as to why headphones appear to 'burn in'. - Page 11

post #151 of 261


 

Quote:
Originally Posted by Prog Rock Man View Post

So this thread turned out to be a bit of a car crash. I am sorry about calling burn in 'nonsense' in the original post and anything else that made it appear I was laying down the law for others to follow. That was counterproductive and clearly got peoples backs up. It was also unintentional.

 

With my limited knowledge I have read through the various tests and the article I have linked to and would, IMHO conclude

 

- manufacturers themselves do not agree whether burn in exists or not with their own speakers (HifiMatrix article)

 

- there are mechanical changes with speakers (all of the tests linked to)

 

- those mechanical changes do reverse to one degree or another after use.

 

- it is not clear how long the reversal takes. Audioholics and one of Tom Nouaine's tests left the speakers for much longer after use than they were left in other tests. It is clear that the less time between the end of the test and the measurements, the more likely it is to find changes still present in the speaker.

 

 - we need more tests, particularly to confirm whether or not, given sufficient time all speakers will return to their original state after use and with headphone speakers.

 

- if all speakers do return to their original state after use, there is no burn in as commonly described by the audiophile. But, depending on how often you use a speaker, if it takes a day or so to return to its original state, your use of of it may mean that it never has a chance to return to the original state. So, in that case there is burn in.

 

- in any case, to what extent are the changes audible, particularly in terms of improving sound quality?


As a mechanic by trade, I definitely lean towards burn-in as a matter of friction, wear and tear.  Like an engine, at 50,000km it is smoother and more efficient than when new.  Engines also perform differently when in hot weather, cold weather - whether it is warmed up or still cold from morning start.  I do believe on a purely physical and scientific sense - all those factors with car engines - are also legitimate in sound "engines" or technically air pumps in general. 

 

Whether or not this is audible is an entirely different debate.

post #152 of 261

Oh gawd, we had that analogy on page 8 already.

post #153 of 261
Quote:
Originally Posted by xnor View Post

Oh gawd, we had that analogy on page 8 already.


Analogies rock!

post #154 of 261
Quote:
Originally Posted by xnor View Post

Oh gawd, we had that analogy on page 8 already.


Probably, but so does every argument ever presented from both sides in every one of these threads. 

 

When I am re-building modern engines, with variable cam timing and cam lifts - I had to measure bore sizes, selected rings and pistons sizes, main bearing shell sized etc - in knowing the expansion properties of metal and future wear factor.  In doing these things I have wear and tear focus on mechanical items and this influences my stance on burn-in.  Just adding my 2 cents, that's all.

post #155 of 261
Thread Starter 

I understand the analogy, but since speakers have limited movement, especially small ones in headphones and they do not have any contact and so no friction, I don't think it is an equivalent.

 

How much memory do you think speakers have? Are they made of materials that will, after a period of non use return to their original state? Or once changed, does the material stay changed?

post #156 of 261


 

Quote:
Originally Posted by Prog Rock Man View Post

I understand the analogy, but since speakers have limited movement, especially small ones in headphones and they do not have any contact and so no friction, I don't think it is an equivalent.

 

How much memory do you think speakers have? Are they made of materials that will, after a period of non use return to their original state? Or once changed, does the material stay changed?


Anything that moves is subject to friction and heat - in the case of speakers, the rubber surrounds, the voice coil motor - no matter how minute.  Just look at microwaves, it heats things up by vibration - but nothing moves as far as my monkey brain is concerned.  The vibration in a headphone driver must produce heat that affects the suppleness of the suspension in the motor coils in some way, no matter how minute.

 

On a purely scientific point of view, in regards to speaker memory - once any amount of movement is applied, there is wear and tear and this is not reversible.  But the heating up from movement, then the cooling off after wards must affect the material somehow.

 

I'm not entirely convinced I can hear a difference though, but that's my hearing.  Can't speak for others.  My 2 cents.

 

But I do believe I hear the biggest differences in sound between summer and winter - all else being equal - far more than any cable differences or burn-in, I may or may not have placeboed myself into believing.


Edited by SP Wild - 8/24/10 at 10:11am
post #157 of 261
Quote:
Originally Posted by SP Wild View Post

 

But I do believe I hear the biggest differences in sound between summer and winter - all else being equal - far more than any cable differences or burn-in, I may or may not have placeboed myself into believing.


The winter destroyed the cables on Shure E2c.  Thermal shock on the cheap insulation from moving between -10F outdoors and 75-80F buildings.  I don't remember any difference in the sound though.

post #158 of 261
Quote:
Originally Posted by maverickronin View Post


The winter destroyed the cables on Shure E2c.  Thermal shock on the cheap insulation from moving between -10F outdoors and 75-80F buildings.  I don't remember any difference in the sound though.


A little off-topic, but I was thinking more of human tissue suppleness in cold and warm states - in the hearing drum tissues perhaps.  very evident in other orgainic matters - such as when working in a cold morning vs a summer day, when I scrape the flesh from my knuckles how much pain is produced.

post #159 of 261
Thread Starter 

When a speaker cone moves is it not kinetic energy producing largely sound and some heat? IMO the evidence is split as to whether the cones do or do not return to their original state. It may be a case that with certain speakers and certain manufacturers there is burn in.

post #160 of 261

The only thing that is really heating up is the voice coil if you play music extremely loud, or if you feed your cans deadly DC. (for example to discharge your batteries, which doesn't make any sense, but whatever!)

 

If you don't abuse your headphones like described above, the cone movement actually has a cooling effect - and everything is in "balance", ideally to all eternity.

post #161 of 261

Well the surround is heated to some degree by absorbing the vibrations of the diaphragm.  I doubt its anything significant though.  I'd be shocked if it was more than a degree or two on anything but the most ferocious subs of PA speakers.

 

As for headphones, you'd probably have to spend more on the thermometer than the headphones to get that kind of resolution.

post #162 of 261
Quote:
Originally Posted by Prog Rock Man View Post

I understand the analogy, but since speakers have limited movement, especially small ones in headphones and they do not have any contact and so no friction, I don't think it is an equivalent.

 

How much memory do you think speakers have? Are they made of materials that will, after a period of non use return to their original state? Or once changed, does the material stay changed?


There is indeed friction.  Let's be honest about this, people.  SP Wild's analogy is very apropos.

post #163 of 261
Quote:
Originally Posted by xnor View Post

The only thing that is really heating up is the voice coil if you play music extremely loud, or if you feed your cans deadly DC. (for example to discharge your batteries, which doesn't make any sense, but whatever!)

 

If you don't abuse your headphones like described above, the cone movement actually has a cooling effect - and everything is in "balance", ideally to all eternity.


Your supposition is not entirely correct, but, then, of course, you realize that already.

post #164 of 261

Couldn't keep on the sidelines Kevin?    

 

"Every time I think I'm out, they pull me back in."  Godfather III

post #165 of 261
Quote:
Originally Posted by Anaxilus View Post

Couldn't keep on the sidelines Kevin?    

 

"Every time I think I'm out, they pull me back in."  Godfather III


Mea culpa.  Guilty as charged.  

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