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Is burn in real or placebo? - Page 24  

post #346 of 520
Quote:
Originally Posted by Sweden View Post
 

FR can be a very limited type of measurement. I can show you graphs of headphones measuring almost the same and sounding completely different.

That's because they interact with the ears they're on. On a dummy head two completely different headphones can measure similarly, but on different persons with differently shaped ears they will produce a different FR.

 

Quote:
Can you see on a FR graph if the bass is tight, the mids silky, the highs harsh and the soundstage huge? You can see if the bass is tight looking at other measurements though, or at least to some degree.

We have to know what to measure and how to best measure it in the first place if we want to figure out burn in on a scientific level. Or a lack of burn in.

Perceived qualities of bass/highs can be read from FR and harmonic distortion plots. "Silky" mids doesn't mean anything to me, and probably doesn't do to most people.

 

"Soundstage" (I prefer to call it headstage because it's not a soundstage in the speaker sense) is a function of FR difference between channels. Again, a perfectly symmetrical average dummy head will tell you something different than your own head.

 

Many break-in claims are in fact about the FR: bass increased/decreased, piercing peaks in the highs decreased, initially veiled treble increased ... none of which have been shown in any of the measurements taken, but all of which can be explained by the brain getting used to a new reference.


Edited by xnor - 11/26/13 at 6:09pm
post #347 of 520
Quote:
Originally Posted by upstateguy View Post
 

I agree. 

 

While the older listener may not be able to hear the same detail as an 18 year old, the younger listener hasn't been listening long enough to be able to fully appreciate what he is hearing.

This is not a put down either.  :beerchug:

 

Absolutely agree my friend.

 

I conducted a quick experiment some weeks ago. A local electronic shop had Sennheiser HD 598's on sale for $150, so I thought I'd buy a pair and see if I liked them. I was a bit hesitant, because my research indicated that I might not like these particular cans. But, I decided to try anyway, because it was such a good price.

 

I brought them home and hooked them up to my Schiit Magni. Caveat: I am currently running my Magni directly out of a laptop headphone output (I know, I cringe when I think of it), because that's my 3rd setup and I still haven't bought a proper DAC for it. Other bills have had to come first, but I digress...

 

The first thing I did was to run through some audio test tones that I'd generated with Passmark SoundCheck. The other set of cans in use on this setup at present are my old ATH M40fs, which I honestly consider my "worst" set. The HD 598's sounded like crap compared to the Audio Technica cans, much to my surprise. Could that be attributed to more "break in?" Perhaps so.

 

My daughter, who is 18, had come into the room whilst I was doing this, and I was testing high frequency tones. So I handed her the headphones, hit the 15 kHz tone, and asked her if she could hear it. She could. To me, it was dead silent. Then I hit the 16 kHz tone. She could also hear that, which I could not. I didn't try further, but I would expect she could have heard some higher tones, if I'd had them handy.

 

I then played the low frequency tones, which could be heard by both of us, down to somewhere around 20 Hz. I'm happy that I can still hear low frequencies :tongue:

 

Overall, the Senn HD 598's sounded better to my 18 year old daughter, than they did to me - by virtue of her being able to hear high frequency notes that I could not. On the other hand, I preferred the inferior ATH M40fs cans (that are 1/4 the price), but were better broken in than the brand new cans. This reinforces the observation that younger people who haven't damaged their hearing, can quite easily hear higher frequency tones, that us Old Farts (TM) can't hear any more. What each of us considered "better" was different.

 

I can hear some of you thinking: "But those HD 598's weren't broken in! You should have broken them in for a couple weeks then tried them!"

 

Perhaps. Perhaps not. But in the space of two weeks, I might not have been able to return those cans for a full refund :biggrin: To me it was more important to get my money back, than to futz with them for a couple weeks in the hopes that I'd like them later on. So I took them back, and was happy I got my money back. It's an Old Fart thing, lol.

 

I'm applying the adage, that first impressions are usually correct. Not always, but usually. Maybe the Senn 598's would have opened up after a couple weeks of white noise. Or maybe they would have sounded better, if I'd been using a proper DAC, the list of variables could go on. On the other hand, maybe I'm really a Beyerdynamic kind of guy, and I should stick with what I know sounds good to me. My DT 770's sound so much better. And even the ATH M40's were more tolerable under the circumstances. Or maybe my evaluation of the 598's was correct, and I just confirmed it.

 

I'm just glad my daughter didn't say, "Dad, can I have these?"

post #348 of 520
Quote:
Originally Posted by xnor View Post
 

That's because they interact with the ears they're on. On a dummy head two completely different headphones can measure similarly, but on different persons with differently shaped ears they will produce a different FR.

 

Perceived qualities of bass/highs can be read from FR and harmonic distortion plots. "Silky" mids doesn't mean anything to me, and probably doesn't do to most people.

 

"Soundstage" (I prefer to call it headstage because it's not a soundstage in the speaker sense) is a function of FR difference between channels. Again, a perfectly symmetrical average dummy head will tell you something different than your own head.

 

Many break-in claims are in fact about the FR: bass increased/decreased, piercing peaks in the highs decreased, initially veiled treble increased ... none of which have been shown in any of the measurements taken, but all of which can be explained by the brain getting used to a new reference.

I sounds like you contradict yourself with the two first paragraphs. First you say FR from dummies is irrelevant as the real FR is only in place with the sound interacting with the listeners ears, but than you lay all this importance on FR plots being paramount to perceived qualities.

Maybe I'm just confused by how you write things.

 

Don't make a hang up on silky. You can put any quality of the mids like clear, detailed, warm, harsh, thick, thin etc.

You still can't tell from a headphones that basically measures like a straight line from 1 khz to 20 hz like LCD-3 and any TWFK driver in-ear.

To say that all the difference in quality in these frequency span can be checked for by simply looking at FR and distortion figures is false.

Even if you also have cumulative spectral decay plots and 30 and 300 hz square waves to look at you can only say so much. Those are at least better than only looking at FR.

 

Can you elaborate on the section I bolded. I have not heard anything like this before. Maybe point me to a scientifically done test.

Do you also explain imaging in this way as well?  I heard imaging explained in other ways.

 

 

I've started a small experiment on my own.

I have a 18 month old JVC FXD70 that have been reported to demand long burn in time and change for the better. Speculation have been about the stiffer nano tube drivers damanding longer time to loosen up. I let that be a side note I don't comment on.

 As it was a favorite of mine and cheap I ordered a spare one in case the model was discontinued.

 

The new one is clearly more trebly and harsh as the biggest difference, but also not as open and dynamic sounding.

I can clearly tell when doing a side by side comparison which ones is which, and in a room with mood lighting it's impossible to tell them apart physically.

Of course individual production differences could be the only cause of difference in sound. 

Let's see when the newer one have 300 hours of play time if I can tell a difference at all.

post #349 of 520
Quote:
Originally Posted by Sweden View Post
 

I sounds like you contradict yourself with the two first paragraphs. First you say FR from dummies is irrelevant as the real FR is only in place with the sound interacting with the listeners ears, but than you lay all this importance on FR plots being paramount to perceived qualities.

Maybe I'm just confused by how you write things.

I am not saying FR measurements from dummy heads are irrelevant, but that the FR will look slightly different on any person's head. This point was made as reply to: "two headphones measure similar but sound different". A simple lack of seal can easily mean a difference of 20 dB at low bass frequencies.

 

This doesn't change the second point that FR is very (I'd argue the most) important measurement.

 

 

Quote:

Don't make a hang up on silky. You can put any quality of the mids like clear, detailed, warm, harsh, thick, thin etc.

You still can't tell from a headphones that basically measures like a straight line from 1 khz to 20 hz like LCD-3 and any TWFK driver in-ear.

To say that all the difference in quality in these frequency span can be checked for by simply looking at FR and distortion figures is false.

Even if you also have cumulative spectral decay plots and 30 and 300 hz square waves to look at you can only say so much. Those are at least better than only looking at FR.

I don't know what you're saying, and I'm no in-ear guy at all. FR technically includes phase so is just a visualization of the impulse response. CSD is just a visualization of the impulse response as well.

Sure, both have their pros and cons.

 

Why can a difference in quality not be determined by those and distortion measurements? Are there magical hidden properties?

 

 

Quote:
Can you elaborate on the section I bolded. I have not heard anything like this before. Maybe point me to a scientifically done test.

Do you also explain imaging in this way as well?  I heard imaging explained in other ways.

I was talking about the reproduction side. The headphones primarily change the FR both overall and between channels.

 

Headstage vs. soundstage is a more complex matter, but basically what you lack with headphones is sound from the right speaker reaching your left ear with a slight delay and vice versa - hence crossfeed and such.

Sound sources are localized heavily using per-ear frequency response and of course also time delays between them at lower frequencies. (Google: HRTF)

 

 

Quote:

I've started a small experiment on my own.

I have a 18 month old JVC FXD70 that have been reported to demand long burn in time and change for the better. Speculation have been about the stiffer nano tube drivers damanding longer time to loosen up. I let that be a side note I don't comment on.

 As it was a favorite of mine and cheap I ordered a spare one in case the model was discontinued.

 

The new one is clearly more trebly and harsh as the biggest difference, but also not as open and dynamic sounding.

I can clearly tell when doing a side by side comparison which ones is which, and in a room with mood lighting it's impossible to tell them apart physically.

Of course individual production differences could be the only cause of difference in sound. 

Let's see when the newer one have 300 hours of play time if I can tell a difference at all.

The speculation doesn't make (common) sense / to me at all.

It's the diaphragm that is made out of "nanotubes", and diaphragms are supposed to be rigid. If you loosened up the diaphragm you would get strong break-up, drastic rise in distortion, nulls in the FR etc.


Edited by xnor - 12/10/13 at 11:14am
post #350 of 520

I think that a large part of what changes on new headphones as they break in is about the seal around the ears. Like an old comfy pair of shoes, after many hours on your head your headphones slowly mold themselves to you. This would also explain why some headphones seem to need breaking in and others don't. If they fit really well right out of the box and don't change much over time then there would be no change during the initial usage. OTOH, if small changes over time in the seal might have large effects on the sound.

post #351 of 520
Quote:
Originally Posted by Sxooter View Post
 

I think that a large part of what changes on new headphones as they break in is about the seal around the ears. Like an old comfy pair of shoes, after many hours on your head your headphones slowly mold themselves to you. This would also explain why some headphones seem to need breaking in and others don't. If they fit really well right out of the box and don't change much over time then there would be no change during the initial usage. OTOH, if small changes over time in the seal might have large effects on the sound.


You are correct that the seal changes. That also changes the distance between the transducer and your ears, and the volume of air inside the cup. That continues to change as the pads wear in. Whether that's a "large part" of what you're hearing, is a matter of some debate.

 

As that seal changes, the amount of air (if any) passing between the pads and your head can change. That also has an affect.

 

Other things that can change on headphones: the material that the transducer is made from is going to wear in a bit also. That material is connected around the outside diameter to the body of the headphone, and in the middle to the voice coils that make the whole contraption vibrate. The stiffness of the material itself will change over time as it spends time vibrating at all sorts of frequencies, and that will affect the character of the sound.

 

The voice coil at the center of the headphone hopefully isn't touching anything (otherwise you'd hear an annoying buzzing sound as they play). If headphones are over-driven to the point where the voice coil is over-heated, it can cause the assembly to warp. If that happens, the character of sound reproduction will also change. Worst case, the voice coil can start rubbing on the magnet assembly, and at that point your cans are blown. I've blown out full size speakers before - have torn them apart just to see what happened.

 

I do believe in physical break in (though I don't call it burn-in, because it isn't). Mechanical devices wear. Proof of that is the fact that they eventually wear out and need to be replaced (your car for example). I don't know and don't care to speculate how much any of the items above individually contribute to whatever changes in sound we might hear. But clearly, enough people hear them to make me a believer.

 

I do however also believe our ears change, in ways that no one has sufficiently explained (to my knowledge). I've heard my own gear change, just by switching components around (using equipment that ought to be well past break in). Personally, I think our ears are the biggest variable in this deal.

post #352 of 520

Placebo is a bit poor word choice in my opinion. 'Adaptation' is the key word here. ALL human senses adapt to stimuli. This is a biological and physiological well studied fact, and it explains the 'burn-in sensation' we experience.

post #353 of 520
Quote:
Originally Posted by Soundwave76 View Post
 

Placebo is a bit poor word choice in my opinion. 'Adaptation' is the key word here. ALL human senses adapt to stimuli. This is a biological and physiological well studied fact, and it explains the 'burn-in sensation' we experience.

 

Well, yes and no. It's just a bit too easy to button it up like that and chalk it all up to sensory adaptation.

 

Burn-in is an electronic phenomenon most properly used to describe something that happens during and after the manufacture of vacuum tubes. It is not a physical sensation. I've explained it in prior posts in this thread and will not repeat it here.

 

Break-in is a physical phenomenon that is most properly used to describe how mechanical devices change over time as they are used. Headphones are both electrical and mechanical devices.

 

Solid state devices (e.g. transistors and IC chips) do not burn in. They are made from silicon, and are quite stable in use.

 

All that being said, our perceptions do also change. But they are not the only things that change. Hence the great difficulty at coming to some consensus as to all of these effects going on.

post #354 of 520
What about the 30 year old capacitors in classic amps that are replaced to reinvigorate the amp, have these 'burnt in' or 'burnt out'? My point is that does burn in (or wear in) always improve things as seems to be considered likely by most?... Do manufacturers design and tune audio equipment to sound great out the box or does the design and development process actually mean that we are likely to experience an improvement?
For example I have 2 pairs of Sony nc-020 (dynamic driver iems), one set with probably 3-4 hundred hours while the other pair have less than 70 hours..
I prefer the newer, slightly tighter ones, so 'wear in' should not be expected to necessarily be a good thing.
Edited by Ari33 - 12/24/13 at 9:57am
post #355 of 520

Has anybody ever heard anyone report that the sound changed to WORSE after burn-in / break-in?

 

Indeed. ;) If we would search ALL burn-in and break-in strories here from Head-fi, I bet you the results would be 99% positive. In my opinion this hints again to human sense adaptation quite strongly.

post #356 of 520
Quote:
Originally Posted by Soundwave76 View Post
 

Has anybody ever heard anyone report that the sound changed to WORSE after burn-in / break-in?

 

Indeed. ;) If we would search ALL burn-in and break-in strories here from Head-fi, I bet you the results would be 99% positive. In my opinion this hints again to human sense adaptation quite strongly.

+1. that is what I believe as well.

 

when I was first starting out on my headphone journey, I actually did think that I gotten sonic improvements with a pair of m100s due to burn-in. I actually ended up w/ x2 pairs of the headphones d/t retailer error, so I was able to do a blind direct A/B test. I found that the effects that I thought I felt was most psychological as I do not accurate pick out which pair of headphones is which. personal experience of course, so ymmv

post #357 of 520

http://en.wikipedia.org/wiki/The_Practice_Effect

 

Not burn in, this is just a artifact of space and time control.  In the above (fictional) book, the more things are used the better they become.  Only saving things deteriorates them.  Rich people employ the poor to use items until they improve enough to befit the high class folks in society. 

 

But, yeah, why doesn't anything burn in and get worse?  Things that make you go HMMMM!

post #358 of 520
Quote:
Originally Posted by Ari33 View Post

What about the 30 year old capacitors in classic amps that are replaced to reinvigorate the amp, have these 'burnt in' or 'burnt out'? My point is that does burn in (or wear in) always improve things as seems to be considered likely by most?... Do manufacturers design and tune audio equipment to sound great out the box or does the design and development process actually mean that we are likely to experience an improvement?
For example I have 2 pairs of Sony nc-020 (dynamic driver iems), one set with probably 3-4 hundred hours while the other pair have less than 70 hours..
I prefer the newer, slightly tighter ones, so 'wear in' should not be expected to necessarily be a good thing.

 

Your point has been brought up before. It is a very curious observation that, more often than not, people experience improvements in SQ over time, as opposed to degradations in sound quality. However, that is not always true. A few people have reported degradations. In my own case, as I was writing this particular review, I noticed that the re-combination of two different amps and DACs had the unintended side effect of making one pairing sound better, and another sound worse. Even stranger, the mixing up of what I was "used to" seems to have forever altered my perceptions of my own gear. Now, one of my favorite combinations is my Modi Dac driving a Bravo amp (where previously I would never have considered swapping my Magni out).

 

Now, has this belief in a break-in period for damn near everything become so entrenched in our hobby as to create a perception of improvement, whether it actually exists or not? That really is the point of this thread. If a manufacturer tells you to expect a break in of X hours, and your gear will sound "better" after that, then that is what you expect to happen (whether it really happens or not). Psychologists might call this a "conditioned response." Hence, one might reasonably wonder if "burn in" or "break in" is real.

 

As I pointed out in a few earlier posts, I spent nearly 15 years of my life working for a company that made some really hi-tech vacuum tubes. A part of the manufacturing cycle was something we variously called "aging" or "burn in". That process helped stabilize the output of the device, and it also told us whether it was going to last for its intended lifetime or not. These were not audio tubes, but they were similar in concept, enough so that I think I can speak with at least a little bit of confidence in what I'm saying. Our tubes were expected to last at least 15 years in service 24/7, so we had to make sure they were going to work long-term. So for vacuum tubes, burn in is a very real phenomenon.

 

As to your question regarding classic (e.g. OLD) amplifiers, stuff does wear out. Over time, some components do change - which I would think is especially true of capacitors, simply because of the way they are made. Electrolytic capacitors are basically two conductors immersed in a liquid media separated by a dielectric medium. 30 years of heating that up every time the amp is run is going to make some physical changes occur, and those physical changes probably alter the original specs of the device. If the capacitance changes significantly, then you have altered the design of the circuit (which may result in better - or worse - performance). Replacing them will bring the circuit back to its original design, and probably make things sound better. There's nothing particularly phenomenal about that. The brakes on your car wear out too ;)

 

Do manufacturers design obsolescence into their products? I am sure that is true in some cases. After all, if you only need to sell someone a car once in their lifetime, then there sure won't be too many auto makers around. It is an absolute certainty that a manufacturer who makes products that never wear out, will only be able to stay in business for so long.


Edited by UmustBKidn - 12/25/13 at 1:11am
post #359 of 520
Quote:
Originally Posted by Ari33 View Post

Do manufacturers design and tune audio equipment to sound great out the box or does the design and development process actually mean that we are likely to experience an improvement?
I may be wrong on this but I don't think any manufacturer specifies in their literature that their headphones should be burnt in.
I suspect that this is a user construct. Born from equal parts buyers remorse and wishful thinking.
post #360 of 520
100% right. This is a nonsens discussion and total headphone voodoo BS. Where are the experts that can in a blind test proof that burn in exists? There are none! Same is true for a correct build amplifier for a portable hp. At the same volume level none of the so called experts can proof in a scientific blind test that they can hear a difference. (Of course u can hear much louder!) Some people just "want to believe" aka "the mulder syndrom"
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