[swmtnbiker]

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Originally Posted by tomb Why not accept for a moment that there are things not so easily measured?

Oh I do, believe me. Burn-in isn't one of them. As I said in a previous post, if these changes can be perceived by the human ear then they can EASILY be measured by common acoustic analysis equipment that is many times more sensitive. Easily. There's nothing here to make a leap of faith about.

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Originally Posted by tomb Frankly, the anectodal testimony is plentiful enough to indicate a reality that is not easily dismissed.

This same logic is used to rationalize the fact that despite thousands of sightings and first-hand experiences, no concrete physical evidence yet exists to prove the existence of Bigfoot, the Loch Ness monster, or small gray aliens that supposedly abduct people on a regular basis. NONE. The big difference between these crypto-zoological and extraterrestrial things and burn-in is that burn-in can easily be proven or discredited with simple test equipment and standard, well-established scientific method.

 

[swmtnbiker]

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Originally Posted by rodbac Actually, I don't think anyone is dismissing anyone's experiences as much as maintaining an alternate (and strongly supported) explanation for them.

Exactly. I'm not discounting the claims of anyone who has experienced burn-in. Obviously something is happening. I'm just very skeptical about the argument, or should I say insistence in many cases, that it's the equipment that's changing.

 

[lmilhan]

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Originally Posted by /\w+/ Burn-in is definitely real, and I have absolute proof. The other day I received my K701s and they sounded terrible. After 5 hours of burn-in they still sounded bad. 100 hours, 200 hours, same thing. Then 299 hours I was contemplating returning them and then, glancing at the clock, I noticed I have now owned the K701s for 300 hours. All of a sudden the sound opened up, and there was so much air. Bass became full and enveloping, and the soundstage became huge!

That's funny...

oh wait a minute, no it isn't.

 

[fzaba]

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Originally Posted by lmilhan You sir, would be wrong (at least from my point of view). I would love to read any proof you may have. I am not so close minded that I would turn my brain off and discount any significant scientific studies that disprove headphone burn in. And I certainly am not above admitting I am wrong (if it can be proven) by any stretch of the imagination. It is a slow day at work, so I would really enjoy reading whatever you have to say on the topic, so post away with those links please! Fell free to enlighten me. Thanks. Edit: Oh yeah, and welcome to Head-Fi.

So sorry lmilhan but I truly do not want to get into it... I shudder just thinking about the days when I would debate with others online over amplifiers and sound quality. =(

Rodbac is doing a damn fine job of it though!

 

[rodbac]

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I think burn-in is hideously overrated, but is much less suspicious than recabling, and probably easier to test for.

Agreed.

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I know, rodbac, that you haven't heard any tests that showed a conclusively identifiable case of burning in, but I've never seen anybody do a real test of this with headphones that disproved it either.

Not surprising- no test will prove it doesn't exist.

If you're looking for cases where the listener simply couldn't tell the difference, I already related one to you, as have many others, and if there is no difference heard, the test doesn't have to be done double-blind or otherwise made valid.

Think about it for a sec and you'll see what I mean. Seriously.

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Why should we assume they couldn't be audible? Is there any evidence for that?

Of course you shouldn't assume it couldn't be audible, but if you assume they ARE audible, there should be ample evidence for it beyond what could easily be considered placebo.

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Why should we refuse the theoretical possibility that this is a material phenomenon when there seems to be at least some reason to accept that it might be one?

First, I'm not saying there is no possibility, and I've clarified that many times (maybe you were directing that quote at someone else).

However, what you're calling "some reason to accept" burn-in as real already has an extremely long-standing explanation for it. We simply don't have to invoke the conclusion of "burn in" as the cause for these reports, especially when they seem to disappear under controlled conditions.

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It's taken to ridiculous extremes here on Head-fi, but now it seems like some people are becoming just as dogmatic against it, with just as many unproven claims, like your "these changes can't possibly be audible" line, rodbac. For shame, to start spouting dogma when you're supposed to be the one talking sense!

Oh for pete's sake. Cut back on the melodrama. I implied that that stance is how the argument goes from the critic's POV, and it was to point out that it's just as reasonable to assume any changes wouldn't be audible (considering the tolerances) as it is to assume they must be.

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good point in itself, but then again, do shoes, say, get less comfortable as they get broken in? Not entirely a spurious comparison, as it's the standard case of stiff new materials getting flexible with use. But perhaps rodbac's shoes have never had a scientifically provable difference after being broken in.

Your reasoning is what keeps this from being a slam-dunk. However, as with many "audiophile" claims, you're assuming that because the behavior occurs in one realm, that it's automatically reasonable to assume it happens in another.

The fact that a 12"x6" piece of leather loosens significantly with constant bending has nothing to do with whether the material in a headphone's driver will experience similar changes with the minute movements it undergoes.

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Except for the smell.

Understatement of the year...

 

[tomb]

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Originally Posted by dpippel Oh I do, believe me. Burn-in isn't one of them. As I said in a previous post, if these changes can be perceived by the human ear then they can EASILY be measured by common acoustic analysis equipment that is many times more sensitive. Easily. There's nothing here to make a leap of faith about. ... snip ...

Your opinion of the human ear is pretty dismissive, considering the culture in which this discussion is taking place. At any rate, measure what? Frequency response - dB - efficiency? Most likely the changes that take place are improvements in transient response and a better fit, neither of which are easily measured or quantified.

 

[lmilhan]

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Originally Posted by fzaba So sorry lmilhan but I truly do not want to get into it... I shudder just thinking about the days when I would debate with others online over amplifiers and sound quality. =( Rodbac is doing a damn fine job of it though!

Uh-huh.

I just wanted you to share your knowledge with me, that is all. Oh well, thanks... umm anyway I guess.

I am not trying to argue with anyone, I was just trying to get to the bottom of if burn in was real or not. I figured your numerous links and knowledge could help me out. Apparently I was wrong.

 

[tomb]

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Originally Posted by lmilhan Uh-huh. I just wanted you to share your knowledge with me, that is all. Oh well, thanks... umm anyway I guess. I am not trying to argue with anyone, I was just trying to get to the bottom of if burn in was real or not. I figured your numerous links and knowledge could help me out. Apparently I was wrong.

Not so. Ultimately, you might turn to the "Sticky" at the top of this forum section - all on PROPER BURN-IN for headphones. That says something about the consensus on certain arguments in this thread.

 

[swmtnbiker]

Quote:

Originally Posted by tomb Your opinion of the human ear is pretty dismissive, considering the culture in which this discussion is taking place. At any rate, measure what? Frequency response - dB - efficiency? Most likely the changes that take place are improvements in transient response and a better fit, neither of which are easily measured or quantified.

Culture has no bearing at all on whether or not something is quantifiable. All of the audio properties you mention can be measured without much trouble. This information is routinely used to market audio products to an unsuspecting public.

By the way, I'm not being dismissive of the human ear. It's a wonderful organ, but it's really nothing more than the equivilant of a microphone. We hear with our BRAINS - this is our sound processor. Why are the proponents of burn-in so dismissive of the role this organ plays in our perception of sound? As I said, some phenomenon is obviously being experienced by people reporting the effects of burn-in. It would be great to get to the bottom of it, whether it's a real physical change in materials or a psycho-acoustic experience makes no difference to me. I've got no personal stake in this argument either way.

 

[ComfyCan]

This question could be answered using the scientific method, but it would take a bunch of headphones and a bunch of people doing blind a/b testing of a brand of headphone generally believed to benefit from a minimum number of hours of burn in.

For example, take the AKG 701; 300 hours seems to be the magic number based on the majority of anectdotal reports.

At a Headfi meet, get AKG to supply 300 or so pairs of new phones. You then get anybody who is willing to particiapte to sit down and listen to a reference track on a pair of new phones, and then to the same track on "burned in" phones supplied by the company or loaned by a few owners (used at least 300 hours).

A few insiders should first screen all phones once to quickly weed out any "Lemons" that are obviously defective, or believed to have sound signatures so different from the rest that they would be likely to skew the results if included in the experiment.

Listening order (new vs. used) should be randomized, so that approximately half listen to the new phones first, and v/v. The volunteers then answer 2 questions: Did one pair sound better than the other? If so, which?

AKG (or whoever) might be persuaded to actually do this for the promotional value; the new phones used in the testing could then be raffled off, sold at cost, or sold with proceeds donated to charity, etc. A magazine might co-sponser the study in order to publish the results.

At the end of the meet, the raw data could be submitted to a statistician to see if there is a statistically significant difference in the subjective impressions of the volunteers. The larger the test group, the greater the reliability of the results.

Such a simplistic study design would not be perfect by any means, but it would be stronger evidence than anonymous, anecdotal impressions of various headphones posted on an internet forum. Such a design would also be relatively inexpensive, and therefore possible.

It probably won't happen, but it would be interesting if it did.

Just imagine the months of fun we'd have poking holes in the results, no matter what they were.

 

[/\w+/]

Quote:

Originally Posted by tomb Your opinion of the human ear is pretty dismissive, considering the culture in which this discussion is taking place. At any rate, measure what? Frequency response - dB - efficiency? Most likely the changes that take place are improvements in transient response and a better fit, neither of which are easily measured or quantified.

Dismissive or not, it's the truth. The human ear is not the last word in sensitivity; especially when compared to electronic measurement tools.

 

[Samgotit]

I'm stealing this from a sane minded observer who once posted about "burn in" (I can't remember who it was). He said something similar to the following:

If "burn in" exist to such a observable degree then why does no one ever claim that after 300 hours their cans sound like s**t and toss them out the window, yet they were spectacular out of the box.

It's interesting "burn in" claims are always on the blossoming side.

 

[sxr71]

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Originally Posted by catscratch Of course burn-in isn't real, how can it be? It's purely psychoacoustics. I mean, how can a constantly flexing membrane possibly change it's physichal characteristics over time? It's really easy to demonstrate. Take a piece of wire and start bending it, over and over, and... oh wait... hmmm...

LMAO!

 

[/\w+/]

Quote:

Originally Posted by catscratch Of course burn-in isn't real, how can it be? It's purely psychoacoustics. I mean, how can a constantly flexing membrane possibly change it's physichal characteristics over time? It's really easy to demonstrate. Take a piece of wire and start bending it, over and over, and... oh wait... hmmm...

It's disingenuous to compare or draw parallels between a headphone driver to a piece of wire. The two have different ductility and material properties and thus the constant flex affects each differently.

 

[swmtnbiker]

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Originally Posted by Samgotit It's interesting "burn in" claims are always on the blossoming side.

One of things that's so interesting about the phenomenon. It's rarely if ever a negative change.