> 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?
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.
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.
> 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.
"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."
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.
"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.
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?
> 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%...