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Comment by falcolas | Hacker News Reader

"What I do know is that during the course of these measurements some things changed. While the data showed only very small differences, the data was clearly above the noise, and a general trend observable. The data also showed a discontinuity around the 20 hour mark in both the FR and THD data. While, it seems to me, much of the change observed could easily be due to movement, especially in the frequencies above 5kHz, some changes seem more likely due to break-in. In particular, the changes in frequency response around the fundamental resonance of the driver at 80Hz, and in %THD+noise at the same frequency and at around 40Hz."

http://www.innerfidelity.com/content/evidence-headphone-brea...

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You missed the paragraph right before that:

> Did I show break-in exists? No. There are too many variables still. Was it simply movement? I don't know. If I did it again to another brand new pair would I get the same results? I don't know. If I did it to an already broken in pair would I get the same results? I don't know.

Testing one pair of headphones one time doesn't show anything.

The author seems to be suffering from a "there's no such thing as headphone break-in" bias. Their results show changes, but they deny it (while subsequently accepting it: "some changes seem more likely due to break-in"). Broader tests would be certainly be useful, but that test certainly doesn't prove that break-in is a myth, either.

Given that people accept break-in is required for, and changes the sound qualities of, larger speakers, it would seem that the benefit of doubt should go to the "headphones do break-in over time". After all, headphones are speakers, just smaller.

To quote John Grado: "All mechanical things need break-in."

Also,

> To quote John Grado: "All mechanical things need break-in."

Really? How many slices of bread should I go through to make sure the pop-up mechanism in my toaster is solid before making my bespoke artisanal toast? How long should I run my oscillating fan before allowing moving air to touch my delicate skin? Should I limit myself to only stapling two pages until my stapler is properly adjusted?

Sarcasm aside, even very complicated pieces of equipment like combustion engines don't require break-in: https://en.wikipedia.org/wiki/Break-in_%28mechanical_run-in%...

Amusing that you bring up engines which do require break in. A brand new motor operates less efficiently producing both less horsepower and less fuel efficent than a broken in motor.

"In general, people no longer break in the engines of their own vehicles after purchasing a car or motorcycle, because the process is done in production." http://en.wikipedia.org/wiki/Break-in_(mechanical_run-in)#En...

Anyways there is very little dispute that headphones sound different off the shelf compared to having been used for a significant amount of time. People dispute if those changes are noticeable or not, but few dispute that the sound signature changes.

Anyways you have brought forth no evidence to support your claim, while dismissing evidence against you opinion as non-conclusive. At the least you might want to be less dismissive and silly with your analogies.

I did in a separate comment:

https://news.ycombinator.com/item?id=7686552

> Shure has tested some thoroughly used pairs of its E1 earphones, which first launched in 1997. And guess what? They measure the same now as when they came off the line. In fact, during the 15 years Shure has been actively selling earphones, its engineers have reached the same conclusion again and again: The sound produced by these tiny transducers during final testing is the same sound you’ll get in a day, in a year, and in five years… unless something goes wrong.

I would agree that IEMs (the E1 is an IEM which is different than headphones) don't require burn in and the signiture change is not noticable. But even your evidence against burn in doesn't dispute headphones with large drivers (traditionally audiphile grade headphones) have sound signiture that alter with use.

Thank you for providing more evidence for my point and against yours. I would reccomend reading past the title next time.

The full paragraph is:

"Matt Engstrom, director of monitoring products at Shure, admits there is evidence that suggests transducers in larger headphones can experience burn-in, and that this could, in theory, produce different sound over time. Again, no one has shown this conclusively, largely because a) companies aren’t rushing to tell audiophiles they’ve been wrong all these years and b) there’s no single industry standard for testing headphones."

Matt Engstrom is not very sure is he? His evidence "suggests" burn-in which "could, in theory" (sounds like the colloquial meaning of 'theory' too, not the scientific meaning) change the sound.

So really no one knows.

> even very complicated pieces of equipment like combustion engines don't require break-in: https://en.wikipedia.org/wiki/Break-in_%28mechanical_run-in%....

As pointed out by modoc below, your link identifies exactly why break-in is still required for motors. That section lays out that break-in procedures have changed over time, but break-in is still required.

The Gamecube controller I bought recently required break-in. I was used to my old, nicely worn one where the analogue control stick was easy to move small amounts from side-to-side, as the internal springs had softened. On a new one, the new springs make the stick feel slightly stuck in the central position.

My newly built Aircooled flat-4 needed running in. Lots of moving parts with fine tolerance needed bedding in. I quickly followed with an oil change to remove the anticipate swarf that resulted. Oil consumption reduced after 500 miles or so as the piston rings sealed up.

Then the vacuum diaphragm on my distributer needed to soften a little. On first use it wasn't flexible enough to move the advance arm quickly within the distributer so my spark advance curve was to low. After breaking it in it is much more responsive.

I would guess speaker diaphragm movement changes as materials wear, weaken or transform into their expected constituency.

Your toaster on the other hand.. maybe the oil will burn off the elements and your toast will taste nicer?

> but that test certainly doesn't prove that break-in is a myth, either

It's impossible to prove a negative. The test was: "is there evidence for headphone output changing over time" and there was not enough evidence to show this by the author's own admission.

Given the ocean of audiophile bullshit out there, it's not unreasonable to take the default position of assuming a claim is bullshit until there is substantial evidence to the contrary.

> The test was: "is there evidence for headphone output changing over time"

And the test was positive, given the test parameters. The author didn't want to extrapolate beyond that (I attribute that to the author's own biases against break-in: "I rarely hear break-in", "voodoo" when referring to break-in), which is their prerogative.

Not to mention that by their very criteria, "all I'm looking for here is a clear trend where the data changes smoothly from the start to the end reference", it did happen.

However, theirs is not the only test out there which shows differences over time. In my limited googling, the consensus seems to be "headphones do break in, even if the effects are limited".

My limited googling shows the opposite:

http://www.wired.com/2013/11/tnhyui-earphone-burn-in/

Since there was only one test of one pair with no control, we don't know if the difference is a manufacturing variable, a testing error, or something else.

I don't know enough about statistics, are the differences shown by the author statistically significant?

What do you think permanently changes electro-mechanically during this mythical "break in"?

The mass of coil and diaphragm? Can't.

The compliance of the surround? Won't.

The resistance, inductance or capacitance of the coil? Can't.

The shape or size of the chamber? Can't.

The magnet strength? Won't.

The coil/magnet coupling? Can't.

The relative placement of interacting parts? Won't.

The stiffness of the diaphragm? Won't.

I think that about covers all the possibilities. It is far more likely that the listener's perception changes due to expectation. Far, far more likely.

Replying to minikites here:

your link says: "For many kinds of equipment (with automotive engines being the prime example), the time it takes to complete break-in procedures has decreased significantly from a number of days to a few hours, for several reasons."

So the break-in period has gotten smaller, but certainly isn't gone. Also many/most modern car/motorcycle manufacturers still have break-in periods specified lasting hundreds or thousands of miles.

That article is a little light on the details of the test setup and measurement procedure but, if I'm reading it correctly, he played pink noise at a fairly high level for ~90 hours straight. The measured differences are likely due to voice coil heating and slight position and seal variations over time.

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