My theory as to why headphones appear to 'burn in'. - Page 17

I'm not arguing whether break-in exists or not. I just thought that his slightly provoking post needs a 'soothing' reply.


The thing is that burn-in, like in the case of the K701, usually is described as a drastic change and people speak of day/night differences. Sure it's nice to see how excited people are about their purchase but at some point there should be a reality check.
The differences you measured are small and were influenced by a number of variables - it might have been the pads, or gravity, or really a change of the diaphragm/driver, or because of temperature changes of the voice coil etc... nothing new if we look at the great article, but simply posting a random graph with a sentence or two is misleading.
So it's already very unlikely that one could even hear a fraction of a dB difference in the lowest octaves in an ABX test where you can easily switch between A and B. But with burn-in you have like on chance to listen to A and after a couple of hours you can listen to B. It's virtually impossible to do a before/after comparison, unless there were really huge changes. But even then I wouldn't bet to be able to correctly identify changes that occurred over a couple of hours.
Edited by xnor - 4/26/11 at 1:27pm

That's to be expected from you.  Non topical, personal sensitivity.

 

As I said earlier I've only experienced 'break-in' in about 20% of cases if even that.  The PRO2500 is my prime example.  I still believe that it is better to approach science w/ an open mind rather than a epistemological dogma like some do here.  Throwing about snide remarks cloaked in the banner of 'objectivism' is anything but scientific but religious hypocrisy.  Regardless, the OP wanted data and there it is.  One more set of data points to consider.  Ignore it, believe it, your call.  I don't care.  I don't even know why you are choosing to engage me personally rather than the data.  As I know you are a fan of the 'report' button I'm surprised you haven't figured out 'Ignore' yet.  So if you don't mind keeping your personal issues w/ me out of the forums.  I'm pretty tired of it frankly.    

 

I don't care if you see it like that, but I care about misleading posts.


btw, I added an explanatory paragraph to my previous post while you posted this

Self-irony?

When I wrote that 'soothing' reply I didn't mean to engage you. I wanted to change the direction from 'Ohhhh look a graph that shows something, I'm sure it's BURN-IN' to well, see above.
Edited by xnor - 4/26/11 at 1:42pm

I don't see what's misleading about posting a link to the entire article.  It seems to me I even predicted your response so you didn't even have to chime in.  Did the work for you.

 

Anyway, have nice day.

Then what did you mean to say with "Here's some colored squiggles for the 'objectivists'. All inaudible by the standards of those who know better of course."?
And not everyone is going to read the whole article.

G'day!
Edited by xnor - 4/26/11 at 1:49pm

 

 

Let’s take an imaginary trip back to the AKG factory.  The new flagships, the 701s are coming down the conveyor on route to packaging.  The chief engineer grabs one of them off the assembly line to randomly check quality control.  He plugs it in to a special amp that’s designed to swing the large amounts of current the 701 needs.  He flips on his source, powers up the amp and listens to what every new AKG 701 owner is going to hear.  Then he exclaims:

 

"Heilige Scheiße, das klingt lausig. Dies ist nicht wie der Kopfhörer, haben wir in Wien. Holen Sie sich jetzt hier runter, Hans, ich möchte wissen, was passiert ist .....

.... Was sagen Sie? Sie werden schließlich gut klingen, aber sie haben zu laute Musik für zwei Wochen zu spielen. Hans, das ist eine schreckliche Sache. Ich möchte Sie in diesem in der Anleitung zu erklären, so dass die neuen Eigentümer verstehen, dass es einige Zeit dauern kann, bevor die Kopfhörer klingen gut. "

 

 

 

 

 

Google tells my you're saying naughty words in German....

EDIT: And yes, that would be pure win if it ever happened.
Edited by maverickronin - 4/26/11 at 11:05pm

One would think, wouldn't one, that if AKG was aware, and how couldn't they be if it was true, that their flagship headphone needed a 300+ hr. burn in period to reach it's potential, it would have been stated somewhere in their literature.
 

The fact that nothing was ever said, leads me to believe that when AKG checked the assembly line for quality control, they found that the headphones coming off the line sounded just like they were supposed to sound.... like the originals in Vienna with thousands of hours.

 

OTOH, The more I think about it, the more I think burn in is really a form of deterioration.  Everything deteriorates from it's new pristine condition.  Tubes deteriorate.  SS devices heat up, deteriorate and burn out.  The LCD screen on my old computer is a shadow of its former brightness. Why should headphone diaphragms be any different?  My speakers deteriorated over the years.  Tweeters burned out, woofers had to be re-foamed and cross overs had to be replaced.  I have an old Sherwood tube receiver that has deteriorated to the point where it needs a complete overhaul.....

 

So maybe, just maybe, if it can be shown that there really is an audible change after 300 or so hours, that the 701s have deteriorated enough from their pristine full frequency response to one that is more tolerable..... nah, there's no such thing as burn in.  Tull's numbers were too small to be audible and apparently there were too many variables to draw conclusions.

You're saying that burn-in as such does not exist because it's just a process of deterioration meaning that over time the headphone diverges from its ideal (fresh out of the factory) properties, right?
Makes sense. Basically it's a matter of definiton.

If we look at the original use of burn-in, for example for electronic components, we can see that it's used to detect components that would fail due to a high initial failure rate before they are being placed in service.

Burn-in of headphones on the other hand is for example defined as (from the burn-in faq):
There are at least two problematic points here,
1) that the definition implies that the pristine state of the headphones is not their intended state, and
2) that the process of burn-in slows down or stops at some point when the state doesn't really change anymore and could be considered final

In my opinion 'burn-in' is a misnomer here and 'break-in' would probably be a better term for what is described above.
Break-in of engines is usually done in production and not by the customers themselves.
I don't know of manufacturers that do the same with headphones - the big question is why.

Maybe because
- a headphone's pristine condition is the ideal one and everything else that follows just causes deterioration from that
- or the process simply does not slow down
- or the changes are to small to be audible anyway
- or bigger changes are for the most part only temporary (for example due to heat build-up inside the driver)
- or ...
Edited by xnor - 4/27/11 at 5:02am

Most mechanical things have that sort of slow decline you're taking about.  Especially if they are simple.  More complicated mechanical systems like car engines or something generally stay on an almost flat performance curve until the very end of their lives until some critical part breaks or wanders out of spec and causes the whole system to fail.  Most electronics are the same way though there are some exceptions like the slowly fading backlight in your LCD screen.  I'd imagine that headphone transducers would could as simple enough (since they don't depend much on other parts) that they'd have that sort of slow gradual decline.  Its undoubtedly much slower in a headphones than something like a large woofer which may need some maintenance 10 or 20 years down the line.

Wrong, wrong, wrong.  Even Jack Woo will tell you not to run his amps for more than 8 hrs at time so they have time to cool off.  And when heat is not the enemy, there is still is failure......  I have a Zhaolu dac that never even got warm, but one day just stopped working. I have a barely used Yamaha CD player that also stopped working, and my favorite SS vintage amp abruptly quit producing bass one day.  I had a new HD fail in one month.  I could go on but you get the idea.  Most electronics  begin deteriorating from the minute you turn them on and mechanical stuff deteriorates faster.  There are exceptions, of course.  Cars have improved over the years but still need maintenance.  Some of the newer electronic devices and components have a pretty long MTBF, if you get a good one.

 

Deterioration and burn out can be argued but I'm not married to either concept.  The decline can slow, the decline can be fast, and the decline can be abrupt, and some of the stuff, like the Mars Rovers, works well past their expected life times under the harshest conditions.

I don't believe in burn in to be honest.  Sure I haven't heard too many headphones, but the sound and perception of my headphones changes very often-  I attribute this to something mental than real physical changes going on.  If I was told by an "expert" something was wrong with my headphones I would start hearing differences that aren't really there.  I think same thing goes for burn in.  If people aren't satisfied with their headphones on first listen, and they discover they may need to "burn in" their mind will trick them into hearing a differences, which is really them just being content with their headphones.  Burn in can't create a new pair of headphones.  The differences can't be stronger( frequency wise) than something I can do with my EQ.  When I firstgot my Grados I thought they were too dark at first( compared to how they should sound going by this board).  Eventually they became just right and they were no where near dark.  As I started smoking weed and listening to to them over a series of weeks they suddently started becoming too bright.  I would think thats an issue of contentment- just feelling a need to overanalyze.  Eventually the brightness got so annoying I poked some holes in the foam covering the driver which caused it to be too dark to me.  It lost all the detail, and was much too bassy.  I got them sent for repairs; brand new drivers.  Once I got them back, they were right at that perfect level of brightness and, they didn't sound dark in the least.  Something that totally contradicted my first impression of them. 

 

I think the fact that so many members on this board( as well as the subject of burn in being so subjective)  who have heard so many headphones( and have much more experience than me, being able to pick up on subtler diffrences between headphones)  dispute these big, leaping differences in sound due to some underlying, physical reason, then its really not creating much of a sonic change to begin with

 

I suppose it could be real; I'm not saying its not, but in the end the headphone is still 99.9999 percent the same headphone it was.  Getting an amp with "wrong" "synergy" could seemingly completely counteract the effects of burn in

 

Edited by DivergeUnify - 4/27/11 at 11:18pm

^ Didn't read the thread.  

 

Could you also point out a single post where someone claimed burn/break-in was > than the effect of EQ?  Or where a DBI700 turns into a Grado RS1?  Thx.

Edited by Anaxilus - 4/27/11 at 11:42pm

I skipped between pages, and read a decent amount

 

My point isn't that someone made the claim that burn in> EQ; its that burn in, if it exists, is negligible

 

If one's brain can make them forget they have an EQ on, and if EQing produces a greater effect than burn in; I would have to say that its pretty negligible and wouldn't cause a "drastic" change in sound

 

You seem to be making a logical leap that if Psychoacoustics > Burn/Break-in then Psychoacoustics = Burn/Break-in.  This distinction has been discussed earlier.  I think we are in the data interpretation phase atm.  Also using 99.9999% is not only a random hypothetical figure but irrelevant.  If I buy a car which is a 2001 zzw30 chassis w/ a 1zz-fe engine and compare it to a 2003 zzw30 chassis w/a 1zz-fe will they drive exactly the same from 0 miles to 50k miles?  They are 99.9999% the same over that period of time and 99.9999% the same vehicle off the assembly line.  Whether it's product variation or use over time, measurements would vary between the two in MPG, Output power, Compression testing , etc, etc.  You would likely notice differences just from driving both of them at either stage of the experiment.  How do I know?  My friend and I have two 2005 zzw30's bought and received at the same time and are factory certified to work on automobiles and track our cars.  The point is not to say a car = a headphone.  The point is to say that your perceived sameness in content and construction does not guarantee or translate into sameness in audio reproduction.  I think you might be misunderstanding the concept of Burn/Break-in as it's being used here and making a lot of intuitive leaps of faith along the way.

Edited by Anaxilus - 4/28/11 at 12:49am