[Acoustic Chef]

Quote:

Originally Posted by amanieux /img/forum/go_quote.gif 1/ do people that say that burn-in improved their headphones, made measures ( like putting a microphone before and after and compare waves on their computer ? 2/ do people that say that that burn-in improved their headphones, made a comparison with older headphones as a reference ? - my experience showed no improvements after 100 hours of burn in when comparing before and after with my olders headphones as references so from my 2 experiences , (unless my new headphones had already been burned in at the factory (audio technica, grado)), my conclusion is : burn-in is busted . - good sens makes me also think that if burn-in did really improve sound it would be made by manufacturers themselves. don't you think so ? - what are your experiences on the subject ? can we collect informations and draw a final conclusion on this controversial question ?

Are you really questioning burn-in..?

I recommend a new hobby if you are.

 

[fordgtlover]

What about the effects of variation in humidity and temperature - do people think they effect the sound?

If burn-in is caused by changes in compliance of the speaker materials, wouldn't heat and humidity cause changes to the material as well.

That would result in climate sensitive headphones, and comments like - don't buy the K701, they sound terrible when it's humid

 

[Acoustic Chef]

Quote:

Originally Posted by fordgtlover /img/forum/go_quote.gif What about the effects of variation in humidity and temperature - do people think they effect the sound? If burn-in is caused by changes in compliance used in the speaker materials, wouldn't heat and humidity cause changes to the material as well. That would result in climate sensitive headphones, and comments like - don't buy the K701, they sound terrible when it's humid

I <3 k701 and hot stickyness.

 

[fordgtlover]

It is often said that we only have an audio memory of several seconds. How then can someone say with any certainty that their headphones (not a set they compared) improved over 100 - 400 (or 1500) hours?

Man, I can't remember where I was 400 hours ago let alone what relatively small changes my headphones have undergone since then.

 

[JaZZ]

Quote:

Originally Posted by fordgtlover /img/forum/go_quote.gif It is often said that we only have an audio memory of several seconds.

Yes, it is often said, but not true. Note that the mental break-in (getting accustomed to a sonic characteristic) claimed by break-in skeptics -- a valid argument BTW -- wouldn't be possible without longer-term audio memory as well.

Quote:

How then can someone say with any certainty that their headphones (not a set they compared) improved over 100 - 400 (or 1500) hours?

There can be no absolute certainty, but most people have a sonic reference in the form of another headphone, which makes the effect somewhat controllable. Moreover, some people break their new headphones in with just occasional control auditions during the process, so mental break-in should only play a minor part.
.

 

[Donnyhifi]

When I picked up my first pair of new Grados, the SR80, I thought they sounded horrible. The highs were tinny, the mids were recessed and lifeless and the low end was seriously lacking. I brought it to my friend Joseph's house who also is a critical audio freak and he told me they sounded OK but he didn't have the heart to say they sucked because I spent so much on them ($180cdn dollars). Disappointed, I read up on these forums and decided to "Burn Em In"

After leaving them running non-stop on my HK AVR-130 HT Receiver, they started opening up. By the third day, the bass had impact, the mids opened up and the trebles sparkled.

Then a couple months later, Joseph came to my house and tried them on and he was really impressed with the SQ, now Joseph owns my ex SR80 and loves them.

Donny

 

[stevenkelby]

What a thread! If I had the cash I would buy everyone 2 pairs of ED9s. One to burn in for 300 hours and one to keep new so you can hear for yourself. Unless you're, literally, deaf. Which maybe some people are.

Some headphones have very subtle changes which some people notice, others don't. Other cans do not burn in at all.

Head-burn in happens too, but that's not what happens to ED9!

 

[Quaddy]

Quote:

Originally Posted by amanieux /img/forum/go_quote.gif - what are your experiences on the subject ? can we collect informations and draw a final conclusion on this controversial question ?

well you already concluded there wasnt burn in.

so how come you are still eager for others opinions? - wavering?

for me in my own little world, burn-in exists, because i have heard the transition for the good with my own ears and own kit.

i am not the slightest bit interested in trying to prove it, as i dont have to, the burden, as always is with non-believers.

in fact i couldnt care less if burn in was a figment of my imagination and didnt tangibly exist, i like what it does for me

 

[WiseOx]

I'll admit I was a bit of a skeptic about burn-in....until I ran 100hrs of pink noise thru my new DT770's....turned them into a whole different can. I burn in everything now.

 

[Kees]

Quote:

Originally Posted by ClieOS /img/forum/go_quote.gif As my old professor once told me, 'Fact' is only a convenient way of saying 'here is what most of us believe in.' Things are constantly being proved and unproved all the time. Even scientific proven 'fact' can turn out to be fake but still attracts millions of believers. You can record the before and after sound of a K701, but there will be those who do hear the difference, and there will be those who don't. You can probably measure the smallest fraction of the difference b/w the before and after sound on a machine, but it certainly doesn't mean you ear will hear the difference, nor does it mean others will/can hear any difference. After all, how can anyone objectively measure the sound quality* of an headphone, which basically is a subjective construct to begin with? We all have different sensitivity of hearing, and we all hear our world slightly different from another person. While you might be able to pickup a -0.5dB over 16Khz and claims that burn in exists, I probably won't hear any change on that range. While you can claims the effect is real as showed on measurement, I could just as well argue that the small change mean nothing to me and burn in is a fake. In the end, there is no absolute 'fact' even in the world of science. In fact, a good scientist should always question the fact, as this has happened more than you can imagine: the same data can be interpreted differently by two schools of scientists. The same professor also once said, data don't tell us the fact, we are the one that interpreted the 'fact' based on what we believe those data has shown us. *as the goal of burn in is basically trying to change the SQ of headphone.

QFT.
Great post.

 

[amanieux]

Quote:

Originally Posted by ClieOS /img/forum/go_quote.gif As my old professor once told me, 'Fact' is only a convenient way of saying 'here is what most of us believe in.' Things are constantly being proved and unproved all the time. Even scientific proven 'fact' can turn out to be fake but still attracts millions of believers.

this is totally false, of course scientific interpretations of FACTS (FACTS=experimental results and not the interpretation you make of it) are changing in time with the constantly evolving threories but numbers measured in an experiment are FACTS that remains valid. if you measure the sound from headphones using a microphones you interpret it as you like but these numbers will not change depending on what most of us believe in.

example :
* fact is : we measure a difference of 0.1dB over 16Khz before and after burn in.

* interpretation is : the best human ear cannot identify a difference under 0.3db over 16khz so we conclude burn in is busted.

so if you want to put in question the interpreation it is up to you but you will have to bring evidence that you can hear a sound difference under 0.3db over 16khz.

note : the number of 0.1 db and 0.3 db is pure invention, i don't have the real numbers, it is just to ilustrate my point. i am a computer scientist not an audio specialist so you guy must have these numbers and draw the conclusion by yourself if your a minimum honest. i have no interest of proving that burn in exist or not, i am just curious (as every scientist should be).

 

[dgbiker1]

Quote:

Originally Posted by DoomzDayz /img/forum/go_quote.gif dgbiker1, your understanding of waveforms is flawed so I don't know if I can take your argument seriously. a 20Khz square wave has tons of harmonics of the 20Khz fundamental. A perfect square wave is thus of course impossible to capture perfectly digitally at all. any harmonics above 20Khz won't be heard by the human ear, but all the harmonics below 20Khz will. so all recordings have less than 20Khz including harmonics. even if an analog recording of a perfect square wave on vinyl existed (i dont know exactly how vinyl works), because our hearing only goes up to 20Khz, that square wave sampled at 44.1Khz will sound exactly the same. I don't believe there are any actual waveforms (not theoretical) that can't be produced without sine waves. My understanding that the nyquist rate will infact reproduce anything perfectly has not been tainted by your argument. From my understanding, the only reason there exist sampling rates above 44.1Khz is because of the heavy processing done on those signals in mixing, mastering, and the like to avoid artifacts/aliasing/etc, none of which happen when we actually listen to it. p.s. the audio critic says burn in is real...

You're absolutely right about the square wave being composed of a fundamental 20Hz wave. But to get a sampling rate that's 10X the frequency of the source means we are reliably sampling up to 4.41kHz. That leaves a large portion of the audible spectrum with some aliasing, and therefore extra harmonics that weren't in the original recording- though many likely won't be audible due to low relative amplitudes. I always go for 10X since that's what we sample biological signals at (where any tiny bump could be an abnormality), but I can imagine audio could be lower, but the "subconscious" (bad word, I mean hardly audible, amplitude << fundamental frequencies) harmonics could be what color the sound, either through us hearing them or even their effects on the dynamics of the headphone driver that may affect the real signal (purely theoretical now). Those higher frequency harmonics could be why digital recordings are seen as cold by vinyl junkies.

This doesn't change the fact that a 2X sample out of phase with the original signal will be completely off though. Plot a sine wave and take two samples; one at pi and one at 2pi. This is 2X sampling and you get a flat line from your "recording" even though the wave has a magnitude of 1. With 44.1kHz you might get a little bump, but it won't be representative of the full wave. Every 10-ish periods you would catch a peak, but 1/10 isn't great sampling.

I'm not saying digital recordings are bad (I prefer CD over vinyl), I just questioned the validity of his argument even though I agree with his conclusions. I'm saying sampling at ~2X will not get you a perfect representation (as I interpreted in the article) of the original source as a perfect analog recording would. In practice 44.1kHz is a perfect compromise of what we can hear (I doubt most people here can really hear a 20kHz signal very well) and data storage requirements. You're probably right about higher bitrates being for signal processing, trying to filter a square wave is a PITA!

 

[amanieux]

Quote:

Originally Posted by Quaddy /img/forum/go_quote.gif well you already concluded there wasnt burn in. so how come you are still eager for others opinions? - wavering?

because my 2experiments are not significant , a valid experiment must be done mutiple time and in multiple configurations to bring enough material in order to start doing interpretations and conclusions. i was just asking people to put here all their experiences to collect data. if your read me carefully i wrote " from my 2 experiences , (unless my new headphones had already been burned in at the factory (audio technica, grado)), my conclusion is : burn-in is busted ". and it is because i am aware that 2 experiences is not significant that i proposed us to regoup all our experiences so we can draw a FINAL CONCLUSION.

a final conclusion which i have not made yet because i read evidences from people that had positive experiences of burn-in. ( especially interested by the post that said that more than one person noted differences from a headphone to headphone comparison beteween an old and a new headphone of the same model but again this is not conclusive because the difference could have pre-existed out of the factory, this experiment must be done with more than 2 headphones like 10 people doing blind test from 10 new headphones and 10 burned-in headphones of the same model).

 

[dgbiker1]

Has anyone ever done a legitimate study of burn-in or tubes vs. transistors or any other audio controversy? Seems like there is so much cash in this industry that some Universities could easily have funded programs researching these phenomena, and we could definitely benefit from some legitimate science behind all these claims.

 

[FrederikS|TPU]

I really noticed the effects of burn in when comparing some new HD 595s I got for a friend compared to my own with like +500 hours on them. The difference was not night and day, but a lot of small things had changed a bit not to say that the brand new HD 595s sounded bad or anything like that. My HD 595s are mint condition so there was a good basis to compare to.