Burning Headphones in: pink or white?

[Slash7]

I know it simply means using them, but on the other hand there's this saying that all the frequencies should
carry the same amount of energy during the burning time...

So in this case, pink noise will be better or white noise? Don't they both have same amount of energy in all frequencies?

[Hugh Robjohns]

So in this case, pink noise will be better or white noise? Don't they both have same amount of energy in all frequencies?

No, that's the fundamental difference between them.

From Wiki: White noise...has a flat frequency spectrum when plotted as a linear function of frequency [and] has equal power in any band of a given bandwidth (power spectral density) when the bandwidth is measured in Hz. For example, with a white noise audio signal, the range of frequencies between 40 Hz and 60 Hz contains the same amount of sound power as the range between 400 Hz and 420 Hz, since both intervals are 20 Hz wide.

Pink noise...hasas equal power in bands that are proportionally wide. This means that pink noise would have equal power in the frequency range from 40 to 60 Hz as in the band from 4000 to 6000 Hz.

Since humans hear in such a proportional space, where a doubling of frequency (an octave) is perceived the same regardless of actual frequency (40–60 Hz is heard as the same interval and distance as 4000–6000 Hz), every octave contains the same amount of energy and thus pink noise is often used as a reference signal in audio engineering...

So you should use pink noise for your burn-in process.

H

[Hrodulf]

We have done some tests regarding headphone burn-in. There are some also done by Tyll Hertsens Innerfidelity

Most if not all effects attributed to burn-in can be explained by pads deforming and improving the seal to the listeners head. Also there are some cognitive effects such as getting used to the sound signature, which will also change the perception of a sound signature.

[Scramble]

Also there are some cognitive effects such as getting used to the sound signature, which will also change the perception of a sound signature.

Well, yes. That's what sceptics like me have been saying for years.

[Slash7]

So in this case, pink noise will be better or white noise? Don't they both have same amount of energy in all frequencies?

Pink noise...hasas equal power in bands that are proportionally wide. This means that pink noise would have equal power in the frequency range from 40 to 60 Hz as in the band from 4000 to 6000 Hz.

Since humans hear in such a proportional space, where a doubling of frequency (an octave) is perceived the same regardless of actual frequency (40–60 Hz is heard as the same interval and distance as 4000–6000 Hz), every octave contains the same amount of energy and thus pink noise is often used as a reference signal in audio engineering...

H

That's what I wanted to know. Thank you

[Slash7]

We have done some tests regarding headphone burn-in. There are some also done by Tyll Hertsens Innerfidelity

Most if not all effects attributed to burn-in can be explained by pads deforming and improving the seal to the listeners head. Also there are some cognitive effects such as getting used to the sound signature, which will also change the perception of a sound signature.

I also heard that Shure have done some tests and they didn't see any changes after burn in process.
Seems like a mental thing...

[Hugh Robjohns]

Most if not all effects attributed to burn-in can be explained by pads deforming and improving the seal to the listeners head.

That's an interesting claim --and which I can see could easily account for differences heard.

I have compared 'burned-in' and 'out-of-the-box' K701s, and the differences were quite noticeable, and then again the two sets after the new one had 'burned-in' which were then indistinguishable.

So for me, the effect of 'burn-in' can be significant with some headphones... but I'd never given much thought to whether it was due to the driver performance changing or the ear-pad's compliance... So that link was very interesting.

The whole burning-in concept is very polarising for people, but I don't see the point. If there is a 'burn-in' change it will happen anyway as you use the gear. If you're worried about it affecting your judgement, you'll do no harm by going through a burn-in process, but you won't get to use your new toys for a while!

Big whoop!

H

[Hrodulf]

One thing is breaking in, which occurs in the first driver excursions, other is saying that some headphones supposedly need more than hundred hours to sound at their best.

[Jeraldo]

My K702's were impossibly hard and steely obnoxious when they arrived. I couldn't grasp what anyone else had possibly seen in them, and they were headed for a return. They were left alone for about three days while connected to program sources and noise, neither relatively loud.

When trying them again after three days they had improved markedly, and since they were not worn in the mean time, I don't think pad deformation had anything to do with it.

They continued to improve with some use and now they are useful and revealing for me.

[Dynamic Mike]

My K702's were impossibly hard and steely obnoxious when they arrived.
When trying them again after three days they had improved markedly, and since they were not worn in the mean time, I don't think pad deformation had anything to do with it. .

I am a little dubious about pad deformation, especially in the early stages of use.

Same. I was a total sceptic with regards to burning in prior to K702's. Regarding the pads deforming, I've got the 65th anniversary edition which have memory foam pads, so I'm pretty sure that wasn't that either. But headphones are essentially mechanical so maybe a slight change initially shouldn't be totally unexpected given the tolerances they're manufactured to. I don't see why a small mechanical change couldn't produce a large audible change.

[Kayvon]

So in this case, pink noise will be better or white noise? Don't they both have same amount of energy in all frequencies?

No, that's the fundamental difference between them.

From Wiki: White noise...has a flat frequency spectrum when plotted as a linear function of frequency [and] has equal power in any band of a given bandwidth (power spectral density) when the bandwidth is measured in Hz. For example, with a white noise audio signal, the range of frequencies between 40 Hz and 60 Hz contains the same amount of sound power as the range between 400 Hz and 420 Hz, since both intervals are 20 Hz wide.

Pink noise...hasas equal power in bands that are proportionally wide. This means that pink noise would have equal power in the frequency range from 40 to 60 Hz as in the band from 4000 to 6000 Hz.

Since humans hear in such a proportional space, where a doubling of frequency (an octave) is perceived the same regardless of actual frequency (40–60 Hz is heard as the same interval and distance as 4000–6000 Hz), every octave contains the same amount of energy and thus pink noise is often used as a reference signal in audio engineering...

So you should use pink noise for your burn-in process.

H

Really? I would've thought white noise would be the one to use in this case?

I thought we use pink noise when we are undertaking a job that relates to how we perceive sound.

Whereas in this case I would have reasoned that the earphone is a piece of equipment that we are asking to respond in a more linear fashion?

I'd be grateful for some further guidance here Hugh as I'm doing some measurements on a microphone I bought and along similar lines as written above I'd used white noise.

Cheers (:

[Exalted Wombat]

My K702's were impossibly hard and steely obnoxious when they arrived.
When trying them again after three days they had improved markedly, and since they were not worn in the mean time, I don't think pad deformation had anything to do with it. .

I am a little dubious about pad deformation, especially in the early stages of use.

Same. I was a total sceptic with regards to burning in prior to K702's. Regarding the pads deforming, I've got the 65th anniversary edition which have memory foam pads, so I'm pretty sure that wasn't that either. But headphones are essentially mechanical so maybe a slight change initially shouldn't be totally unexpected given the tolerances they're manufactured to. I don't see why a small mechanical change couldn't produce a large audible change.

Try pressing the cans very slightly tighter on your ears. I suspect you'll hear a change in sound an order of magnitude greater than any burning in effect.

Which doesn't prove the burning in theory one way or another, of course.

[Hugh Robjohns]

Really? I would've thought white noise would be the one to use in this case?

Use white noise if you want to, but the pink noise spectrum is much closer to the spectrum and energy distribution of music, and thus far more appropriate as a urn-in signal than white noise which has a lot more HF energy and would therefore stress the driver more.

I'm doing some measurements on a microphone I bought and along similar lines as written above I'd used white noise.

As long as you know what the source is, you can judge the measurement results accordingly. But most audio spectrum analysis tools and 1/3octave analysers etc are balanced for pink noise.

H

[Kayvon]

Really? I would've thought white noise would be the one to use in this case?

Use white noise if you want to, but the pink noise spectrum is much closer to the spectrum and energy distribution of music, and thus far more appropriate as a urn-in signal than white noise which has a lot more HF energy and would therefore stress the driver more.

I'm doing some measurements on a microphone I bought and along similar lines as written above I'd used white noise.

As long as you know what the source is, you can judge the measurement results accordingly. But most audio spectrum analysis tools and 1/3octave analysers etc are balanced for pink noise.

H

Aha, I see. Thanks for that Hugh.

RE measuring the microphone, I can remember the BS standard for measuring microphones being pretty thin and not that in depth. Maybe there's a better ITU one? Will go searching.

Cheers again Hugh, invaluable stuff right here on the SOS forums

[CS70]

I don't see why a small mechanical change couldn't produce a large audible change.

Yeah, it would be fun to take scans of two headphones of the same model, burn-in one, scan it again and look at the physical changes beyond the production tolerances.

[The Red Bladder]

I don't see why a small mechanical change couldn't produce a large audible change.

Yeah, it would be fun to take scans of two headphones of the same model, burn-in one, scan it again and look at the physical changes beyond the production tolerances.

This has been done several times and by such reputable companies as Genelec and Sennheiser/Neumann for both headphones and speakers and they always come up with the same conclusions, but the BS brigade refuse to face simple facts.

It's a bit like directional arrows on audiophile speaker cables.

[The Red Bladder]

So in this case, pink noise will be better or white noise? Don't they both have same amount of energy in all frequencies?

And whilst I'm here, one of the definitions of pink noise is random noise of equal energy for all frequencies.

White noise is random noise of equal amplitude for all frequencies.

[Hugh Robjohns]

it would be fun to take scans of two headphones of the same model, burn-in one, scan it again and look at the physical changes beyond the production tolerances.

That's precisely what was demonstrated earlier in this thread! Keep up

This has been done several times and by such reputable companies as Genelec and Sennheiser/Neumann for both headphones and speakers and they always come up with the same conclusions...

The issue of speaker burn-in has been discussed several times before and I dont propose to go over that old ground yet again, but for balance I feel I should also mention that equally reputable companies claim, and have evidence (which we've published on the forum) to show that there is a measurable burn-in effect in some of their designs...

But as I've said before, it makes no difference whether burn-in exists or not, or whether anyone chooses to believe it or not. It's gonna happen anyway, and burning in won't damage the speaker/headphone. Burn-in if you want to, dont if you dont. End of!

[Dynamic Mike]

I don't see why a small mechanical change couldn't produce a large audible change.

Yeah, it would be fun to take scans of two headphones of the same model, burn-in one, scan it again and look at the physical changes beyond the production tolerances.

It's a bit like directional arrows on audiophile speaker cables.

No it isn't. Speaker wiring has no moving parts. If you subject any mechanical suspension system to vibration there will be a degree of fatigue, especially since we're talking about organic polymers such as a typical rubber/resin suspension model. The question is whether or not this is sufficient to produce an audible effect. If we're all pretty much agreed a small amount of damage can have a detrimental effect, it's not beyond the realms of possibility a small amount of fatigue could induce a positive effect.

[Eddy Deegan]

If there is a physical change as a result of extended use, then could the resulting effect it not be measured using a suitable mic acting as an 'electronic ear' feeding a suitable analysis system in software or hardware? This would negate the need to worry about microscopic variations in polymers and so forth as it would only be the end result that was being measured.

Plot the frequency response of a new set of cans, then do the burn in and repeat the process. Given the sensitivity of readily available equipment this would seem an obvious test to perform - though perhaps it has, and perhaps the results have been posted here in the past (as Hugh alluded to).

Alternatively, is it not possible that the headphones don't change, but the listener's brain does? The brain contains a sophisticated filtering system which maps the pressure waves to an experience we call 'sound', but in doing so it removes many things (we don't usually hear our own heartbeat for example). Maybe with repeated listening, the brain adapts to the headphones, becoming more 'familiar' with their frequency response and morphing the above-mentioned filters accordingly such that the subjective end result is genuinely different after time, but without any physical changes of note colouring the sound in the cans.

I have no qualified opinion on the matter and am certainly not asserting either of the above to be the case. Just thinking aloud. I think Hugh summed it up perfectly - it seems a bit of an academic matter as after some use it all becomes moot anyway.

[Dynamic Mike]

Plot the frequency response of a new set of cans, then do the burn in and repeat the process. Given the sensitivity of readily available equipment this would seem an obvious test to perform - though perhaps it has, and perhaps the results have been posted here in the past (as Hugh alluded to).

Yes, but there is a presumption here that the change is frequency based. Equally though it could be transient response, amplitude response, recoil/recovery time, reproduction of tone/timbre that changes. And then you'd need to benchmark the equipment used, and then benchmark the equipment used to benchmark the equipment used... That way lies madness.