[441879]

One of these days, someone with an extra pair of headphones and a lot of spare time is going to put their phones into the freezer to see if there's a change in sound. My phones are too important to me to try. 
 

I live in Alaska and walk my dog a lot wearing over ear closed headphones. As far as I can tell, bass does diminish when it gets cold (and the headphones creak). The most likely reason for the diminished bass is the ear pads getting stiffer rather than the drivers being affected. I have also noticed when I listen to the radio in my car when it's really cold the bass is attenuated. In this case it's probably because the driver surround is just a lot more stiff.

 

[ponyhearts]

I'm experiencing a negative burn-in effect on some of my earphones. I have a pair that has been used for over 7 years and I didn't notice it until I bought a new pair but the bass and mids had dropped out, which made the vocals sound more sharper. As a result, in my old pair, I don't have to turn up the volume as much because the vocals aren't drowned out by the drums, guitar in particular.
 
This gave me a false sense that the new pair were somehow inferior and ultimately confused me for a few days. First is first, I bought the new model and then I bought the old model which happened to still be available (thank god I thought at the time), thinking the new model had some problems, but in fact they were the same once I got home...
 
In particular, I noticed that in my old pair, the guitar strums are missing warmth which is present in my newer pair. I managed to fetch the old model in a clearance sale of a now soon to be non-existent retailer.
 
It turns out my brain tricking me and both new pairs sound identical, which can only mean my old earphones have now degraded.

 

[desik]

My 2 cents.
I have an 8 years old pair of HD485 which I absolutely love. Recently I ordered another used pair on ebay, since the old one has flattened cushions and other cosmetic degradation. Tried the new pair today for the first time. Although the newer one is used, I heard somewhere on this forum that a headset unused for a long time will gradually lose its "burn-in" and will act more like a new one. This was the best opportunity to test the burn-in theory.
 
Below are my freshly made notes. Song: a bass-guitar heavy beginning of a doom metal song.
 
Old HD485:
- bass is more articulate, more detailed
- drums are more punchy
- at some point in the song, when bass guitar chord is stopped, I clearly hear it briefly producing a different tone before stopping.
 
New HD485:
- bass guitar just mixes up with some other instrument, I cannot hear clearly how it stops.
- sound is less textured, more boring
- treble is a tad more annoying, although that's at the limits of my perception.
 
Possible explanations:
- regular burn-in after a couple hundred hours
- continuous burn-in in 8 years of usage
- Flattened cushions on the old 485. Unlikely. If that would be the cause, I would expect a different tonal balance as well. But I mostly hear a difference in detail and instrument separation.
 
Hearing is believing!

 

[Montecristo]

Can't you test to see if burn in actually works? Wouldn't that put the whole debate to rest?

 

[desik]

Unfortunately I had to pack the new HD485 for return, because it doesn't make sound out of one ear. I tested both headphones with one ear only. If I'll get a replacement, I'll definitely do this test. So far seller didn't respond.

 

[castleofargh]

  Can't you test to see if burn in actually works? Wouldn't that put the whole debate to rest?

it's harder to test accurately than we often think. I've tried with my amateurish gears, the pads of a headphone getting compressed and changing the sound a lot, that is real. (but what can we do about it?).
with IEMs I tried with silicon tips, the damn things would slip out after a day(or after 10mn sometimes), so the measurement changes I get may just be the IEM moving a little from it's position(which also can yield very very significant and audible changes). so I tried mc gyver style to fix an IEM and seal it without using tips, stuck between books... and the differences I got were like 0.1db at some frequencies... I could take the IEM out and put it back in the coupler, and get more difference every single time than those variations. so it makes it hard to believe that people, within all the changes from placement, the long time passing, and how unreliable memories are, could still remember the first sounds accurately(they also most likely changed the volume output a few times...) enough to notice some "0,something" difference.
it makes me believe that people dream the changes, like we all do when we look for some. and sometimes it happens that there really are some changes, but the correlation between actual change and reports is yet to be confirmed IMO ^_^.
 
but yeah at least the pads make burn in real for headphones. but I wish I had some better measurement gears to test things "for real".

 

[desik]

 
but yeah at least the pads make burn in real for headphones. but I wish I had some better measurement gears to test things "for real".

The difference was way too obvious to be caused by pads. Still I listed pads explanation for completeness. I might take them out and test in parallel with the same pair of pads, if you nag me enough.

 

[castleofargh]

 

 
but yeah at least the pads make burn in real for headphones. but I wish I had some better measurement gears to test things "for real".

The difference was way too obvious to be caused by pads. Still I listed pads explanation for completeness. I might take them out and test in parallel with the same pair of pads, if you nag me enough.

you're bringing a special case, you could try with little time passing which is a huge improvement and makes me trust that you really heard a difference. not something I believe for too many people when hey talk about stuff changing  withing months. memory is just not that good. 
but the problem with 2 pairs is that it adds one new  variable. they could sound different simply because they're different pairs and manufacturing precision isn't great enough to give the exact same result all the time. I usually get somewhere about 2db variation between left and right ear, and looking at this http://www.innerfidelity.com/headphone-data-sheet-downloads , I'm not alone. so if they fail to do both ears, imagine that they must at least fail as much from pair to pair.
or you can just take all the models where Tyll measured 2 different copies, the differences are there and in magnitude that clearly can be audible. the real question is to know if it comes from burn in, manufacturing precision, the way the headphones were put on the dummy head, the calibration of the dummy head maybe changing a little with time, the temperature and humidity for all I know. it matters, I doubt that it matters audibly, but it's measurable.
 
and it's probably a mix of all those stuff. I'm not saying burn in doesn't exist(even if I would rather call it wear), there are mechanical parts, so they will change with time that is for sure. what I find weird is how people can claim they heard burn in specifically, when there are so many variables, + time, + how we have extra focus and perception when we just got our new toy, +the time to get used to put it in place, and how much the frequency response changes with placement...  how can anybody be confident enough to make burn in claims when it could be so many other things causing the change?
again your example is special, I believe the way you tested is much better, but it's hard to go with the hypothesis that the 2 pairs sounded the same the first day they were used. from my still small experience with measurements, I would bet the  pairs of headphone are audibly different from the start more time than not.

 

[serman005]

Fascinating thread. I've only read two-thirds of it, so forgive me if this has been covered, but, if burin-in is an extant phenomenon, is it different for open vs. closed cans?

 

[Giogio]

Hmmm.
So it is real.
I had read somebody saying that burnin is bulls..., so I have never believed in it. I have just taken for granted that the only real burnin is the one happening in the brain, which gets used (actually very quickly) to almost any given pair of headphones.
But it makes sense that (some) headphones have a burnin, maybe not all of them, maybe depending on which kind of material are used. I believe that some components, the more rigid ones, like plastic, cannot change performance over time. But the softer parts, like paper, rubber etc, those could need burnin.
It may be like with shoes. NEVER go trekking one day long with a brand new pair of high (semi-boot) trekking shoes.
 
Ok then. So, what should I do if I get a Test Unit to review (like I get more often, lately)? How can I force a faster burnin? I remember having read pink noise, I have no idea what that is, can somebody give some tips before I get lost in uncle google?

 

[castleofargh]

anything filtering will get dirty, anything moving will one day break. so of course some things will change over time, else headphones would be eternal, even better than a diamond ^_^.
between the differences in ears, size of the head, and variations from driver to driver, all those variations will most likely have more impact from one guy to the next than "burn in"(beside the pads maybe). the pads being the clear main element of change over time, I would suggest using something to keep the pads pressured even when you don't use the headphone if you short on time. you can also play music to it the first night to rassure the burn in fans(first night in a new home, the headphone may feel lonely

), but I wouldn't bother any further than this.

 

[desik]

It's a sound that has the same energy distribution across the whole frequency spectrum, or something along these lines. Widely considered the most efficient burn-in technique. Audeze LCD-2 have 24 hr factory burn-in with pink noise, by the way. At 95 db, whatever that means. Recommendation is to put the volume at slightly above your comfortable listening level, assuming you're listening at medium volume.

 

[Giogio]

all those variations will most likely have more impact from one guy to the next than "burn in"

the pads being the clear main element of change over time, I would suggest using something to keep the pads pressured even when you don't use the headphone

But within the same guy, the burn in can be more significant, given that it is the factor that supposedly changes faster, right?
I did not get what you mean about the pads...
Anyway I like the idea of pink noise. I want to try it. It sounds exotic.
 
Quote:

  It's a sound that has the same energy distribution across the whole frequency spectrum
Recommendation is to put the volume at slightly above your comfortable listening level, assuming you're listening at medium volume.

Where can I download a reliable pink noise (I do not want to find some homemade thing by some crazy guy).
I tend to listen to music at quite max volume (after all I use Bluetooth Headphones, which are not as powerful as Wired Headphones and cannot be amped analogically).
Should I burn in at let's say 75% vol?
More than 24 hrs is, I suppose, "useless but not harmful"?

 

[desik]

Just google for pink noise, should be ok. I also used the tracks on youtube with no issues. Regarding the volume: if you think the volume you are listening to is rather loud, just keep that volume. Regarding burn-in duration: you better google for it for your particular headphone model. Chances are someone else reported about it. Recommendations range anywhere between 50-300 hrs. Audeze guys know what's the maximum safe volume for their cans, that's why they do the burn-in for just 24 hrs.
 
About the earpad deformation: I recently replaced the earpads on the HD485. The sound really changed. Now they're even more bass-heavy. I actually like them more with old flattened earpads - voices are less recessed. That's so silly

 

[castleofargh]

yeah as desik said, with time the shape of the pads will tend to change(because the foam won't get back to it's original shape indefinitely, or if it's not leather, the surface might become dirty or worn out). in effect, the driver comes closer to the ear as time passes, the inside volume and shape could change, the quality of the seal may change too...  so the signature can change. I don't think anybody is challenging that old pads vs new pads usually don't sound the same.
so if you have little time to test the headphone, I suggested to keep the headphone placed over books or whatever to keep some pressure on the pads and badly pretend like it had been used longer. but I don't know how effective or significant this could be, after all I'd expect at least new foam to behave very well for some time.  
 
about pink noise, audacity. generate -> noise -> pink... and you create the file you need.