Burning in Headphones ? WTF ?

[Lightages]

-I agree that some speakers change over time-

So, you think there exist speakers that don't change over time? Are those some immortal speakers or what?

The only thing constant in life are death, taxes, and now, some speakers!

Those are SOME speakers, I have to say.

I meant that there are some speakers that change very quickly over a short period of time to the point where they can be easily measured and or heard. Everything changes over time of course but I was referring to, of course, the effects claimed for burn in.

[n45048]

I'd like to think that due to the mechanism and make up of a speaker, there are probably some changes which occur over time. I'm of the firm belief that any changes ideally should not affect the audio (or at least do so as little as possible).

If I bought a speaker which experiences a rapid or significant change, I'd be inclined to consider that speaker either defective, poorly designed or made which cheap materials.

I'd expect high quality speakers to undergo very little change and if any such change was indeed desirable, then manufacturers would be putting speakers through a "burn-in" process before being sold to the end-user. Surely any given speaker should perform the same way as decribed in the product literature. If it performed outside of the stated specifications, then could you not argue that there was something wrong with it and have it replaced under warranty? On the flip-side, if "burn-in" was required to enable the speaker to perform according to specs, then would disregarding such a process void the warranty?

If an audiophool told me that a speaker required burn-in to sound "better", I simply can't bring myself to belive it. They'd have to show me clear, quantifiable evidence and explain why any change is in fact better (but that's not going to happen is it?)

[dannyf]

there are some speakers that change very quickly over a short period of time

That's quite different from

some speakers change over time

Either way, as long as you agree that all speakers change over time, burning in is a possibility.

The only remaining question is whether such changes are audible.

I have not heard of any evidence that they are; Nor have I heard any evidence that they are not.

So from the absence of evidence one cannot conclude the evidence of absence.

That's why the audiophools are as stupid as the audiodicks.

[janengelbrecht]

It rather depends on what you are listening to. Classical music in general are not overproduced

I'll take your word for that, it's not something I'd know about.

Most people would be shocked if they knew how much editing and post-production was carried out in classical recordings. However, the end result does have decent dynamic range (though nothing like the original performance - for good reason).

The loudness wars have been around for a lot longer than people realise. They exist because historically audio levels had to be peak-normalised to avoid overloading record cutting lathes, radio transmitters, tape, etc.

By compressing the music, the average level rises, and the audio sounds subjectively louder, even though it is reaching the same peak levels that more dynamic music reaches. The ultimate endgame is where we are now, where tracks have single-figure dynamic range, and are often heavily clipped.

It arguably started back in the days of juke boxes, where in addition to the limitation of vinyl, the reply level was fixed. Motown recordings - the (in)famous "wall of sound" - started the ball rolling. Things stepped up a gear when people started (ab)using Optimod boxes on their radio stations - the '80s was when all that got silly (in the UK at least).

Today, we are much less concerned about running everything up against the maximum level possible, as we have much more dynamic range available to us. It is ironic that when delivery media was limited (vinyl, cassette tape, AM radio), we did have some really quite nice recordings. Today, we have nearly 96dB of dynamic range available to us via 16 bit audio (far in excess of what anyone actually needs for delivery), and a large percentage of "popular" recordings occupy the top 10 dB. Crazy.

The way to end the loudness way is to normalise for average level rather than peak level. This simply means turning down the level of the whole track to the RMS value matches the reference level. Having done this, you find that modern hyper-compressed recordings sound flat and uninteresting, while older recordings with natural dynamics are the ones that stand out. As soon as record producers realise this, recorded music will start to get better again.

Loudness normalisation is something that is being introduced to broadcast environments, and services like iTunes and Spotify are implementing their versions. Let's see what happens...

http://www.soundonsound.com/sos/feb14/articles/loudness-war.htm

http://thequietus.com/articles/13821-loudness-wars-apple-itunes-bob-katz

http://www.digitalmusicnews.com/permalink/2013/10/28/itunesloudness

http://www.soundstudieslab.org/apple-spotify-to-end-the-loudness-war/

It seems: War Is Over

[suicidaleggroll]

The only remaining question is whether such changes are audible.

I have not heard of any evidence that they are; Nor have I heard any evidence that they are not.

Depending on the speaker and material (and above all, the listener's familiarity with the material), it can certainly be audible.  I mentioned earlier about making RTA measurements of my speakers in order to flatten the response multiple times over the first couple of years of ownership, and noticed huge differences in their response after just a couple of months.  What I neglected to mention was that the difference was also easily audible.  These were not .1 dB changes, these were 6+ dB resonances in the midrange that disappeared after several weeks/months, and the low end came up 3+ dB.  The reason I re-ran the RTA after a couple of months was because I could tell that they sounded very different than when they were new.

[suicidaleggroll]

If I bought a speaker which experiences a rapid or significant change, I'd be inclined to consider that speaker either defective, poorly designed or made which cheap materials.

And you would be very wrong.

I'd expect high quality speakers to undergo very little change

Why?  It's still a mechanical device.  Do you apply the same "quality" rules to all other mechanical devices?  More expensive cars don't need their engines broken in, more expensive connectors don't need a few cycles to loosen up, etc.?  In my experience the opposite is true, actually.  The cheaper the device, cheaper the materials, looser the tolerances, the less break-in time that's required (if any).

and if any such change was indeed desirable, then manufacturers would be putting speakers through a "burn-in" process before being sold to the end-user.

I hear the same argument from the engine break-in deniers as well.  "If engines had to be broken in, then surely the car manufacturers would do it before selling them to consumers".  The fact is the resources required to do this on a large scale are prohibitive.  It would raise the cost of the device significantly, and for what?  The break-in is not something that the consumer has to go out of their way to do, it's something that happens naturally as the device is used.  Why would the manufacturer waste thousands of dollars forcing a process that will occur all by itself as soon as the customer starts to use it?

Surely any given speaker should perform the same way as decribed in the product literature. If it performed outside of the stated specifications, then could you not argue that there was something wrong with it and have it replaced under warranty?

I am 100% positive that if a customer called the manufacturer to complain that the speaker's response was out of spec, the manufacturer would respond with three questions.  How is it installed, how is it being powered, and how many hours of play time does it have on it.  If the user responded that it was new, I guarantee you the manufacturer would tell them to put 50+ hours of listening in and then come back if they still had a complaint.  Many manufacturers state right on their site or in the product documentation that the speaker needs xx hours of listening time before the parameters/response will fall in spec.

On the flip-side, if "burn-in" was required to enable the speaker to perform according to specs, then would disregarding such a process void the warranty?

Again, the burn-in isn't something the user has to go out of their way to do, it's something that happens all by itself as the speaker is used.  Some people just like to accelerate the process.

If an audiophool told me that a speaker required burn-in to sound "better", I simply can't bring myself to belive it. They'd have to show me clear, quantifiable evidence and explain why any change is in fact better (but that's not going to happen is it?)

I do wish I had kept copies of the RTA results for my speakers at various ages...it was incredibly clear.

[n45048]

And you would be very wrong.

I don't believe so. But I encourage you to prove otherwise.

Do you apply the same "quality" rules to all other mechanical devices?

Yep, generally. Depending what we're talking about of course. I don't know about you but I'm talking about loudspeakers.

I hear the same argument from the engine break-in deniers as well.  "If engines had to be broken in, then surely the car manufacturers would do it before selling them to consumers".  The fact is the resources required to do this on a large scale are prohibitive.  It would raise the cost of the device significantly, and for what?  The break-in is not something that the consumer has to go out of their way to do, it's something that happens naturally as the device is used.  Why would the manufacturer waste thousands of dollars forcing a process that will occur all by itself as soon as the customer starts to use it?

Again, I'm talking about loudspeakers, not motor vehicles. Using your logic, why do Lithium battery manufacturers bother ageing batteries? Cut out the process altogether and save weeks!

I am 100% positive that if a customer called the manufacturer to complain that the speaker's response was out of spec, the manufacturer would respond with three questions.  How is it installed, how is it being powered, and how many hours of play time does it have on it.  If the user responded that it was new, I guarantee you the manufacturer would tell them to put 50+ hours of listening in and then come back if they still had a complaint.  Many manufacturers state right on their site or in the product documentation that the speaker needs xx hours of listening time before the parameters/response will fall in spec.

100%? Which speaker manufacturer do you work for? How many speakers have you designed and built? How many warrantly claims have you either requested or fulfilled? As for me, I do not work for any manufacturer nor have I built a loudspeaker before. I submitted 1 warranty claim years ago for a speaker and they couldn't give a toss how long it had been used for (in fact, they didn't even ask). You'll also notice if you had actually read my comments that I used an open argument rather than stating a "fact".

Also, please link in some of the speaker manufacturers who specify a burn-in time on their products. I want to make sure I'm doing it right!

Again, the burn-in isn't something the user has to go out of their way to do, it's something that happens all by itself as the speaker is used.  Some people just like to accelerate the process.

That depends on who you ask. I'm sure some audiophool will happily sell you a "special CD" for the low, low price of $79.95 which contains a "scientifically proven combination of frequencies" to make sure it's done "properly", whilst others will just tell you to play Enya really loudly. Then there are those really 'crazy' people who say it's just a load of shit and don't bother.

I do wish I had kept copies of the RTA results for my speakers at various ages...it was incredibly clear.

I wish you did too! (Don't forget copies of your test microphone calibration and charactaristics data which I'm sure got burnt-in when you did your speaker the first time. It might have changed your results) 

[coppice]

Audiophiles are very buzzword driven. Some breaking in of mechanical systems is quite common, and they love talking about breaking in. However, many speakers vary far more due to humidity, and that's just too confusing for most audiophiles, so they don't go on about it. Hygroscopic materials are still very common for speaker cones. They cause so much trouble in tropical locations you would think they might have eliminated them years ago.

[Yago]

And you would be very wrong.

I don't believe so. But I encourage you to prove otherwise.

Do you apply the same "quality" rules to all other mechanical devices?

Yep, generally. Depending what we're talking about of course. I don't know about you but I'm talking about loudspeakers.

I hear the same argument from the engine break-in deniers as well.  "If engines had to be broken in, then surely the car manufacturers would do it before selling them to consumers".  The fact is the resources required to do this on a large scale are prohibitive.  It would raise the cost of the device significantly, and for what?  The break-in is not something that the consumer has to go out of their way to do, it's something that happens naturally as the device is used.  Why would the manufacturer waste thousands of dollars forcing a process that will occur all by itself as soon as the customer starts to use it?

Again, I'm talking about loudspeakers, not motor vehicles. Using your logic, why do Lithium battery manufacturers bother ageing batteries? Cut out the process altogether and save weeks!

I am 100% positive that if a customer called the manufacturer to complain that the speaker's response was out of spec, the manufacturer would respond with three questions.  How is it installed, how is it being powered, and how many hours of play time does it have on it.  If the user responded that it was new, I guarantee you the manufacturer would tell them to put 50+ hours of listening in and then come back if they still had a complaint.  Many manufacturers state right on their site or in the product documentation that the speaker needs xx hours of listening time before the parameters/response will fall in spec.

100%? Which speaker manufacturer do you work for? How many speakers have you designed and built? How many warrantly claims have you either requested or fulfilled? As for me, I do not work for any manufacturer nor have I built a loudspeaker before. I submitted 1 warranty claim years ago for a speaker and they couldn't give a toss how long it had been used for (in fact, they didn't even ask). You'll also notice if you had actually read my comments that I used an open argument rather than stating a "fact".

Also, please link in some of the speaker manufacturers who specify a burn-in time on their products. I want to make sure I'm doing it right!

Again, the burn-in isn't something the user has to go out of their way to do, it's something that happens all by itself as the speaker is used.  Some people just like to accelerate the process.

That depends on who you ask. I'm sure some audiophool will happily sell you a "special CD" for the low, low price of $79.95 which contains a "scientifically proven combination of frequencies" to make sure it's done "properly", whilst others will just tell you to play Enya really loudly. Then there are those really 'crazy' people who say it's just a load of shit and don't bother.

I do wish I had kept copies of the RTA results for my speakers at various ages...it was incredibly clear.

I wish you did too! (Don't forget copies of your test microphone calibration and charactaristics data which I'm sure got burnt-in when you did your speaker the first time. It might have changed your results) 

I did, very early on in the thread I posted a link from the Adam Audio website about the burn in of their speakers.

[n45048]

I did, very early on in the thread I posted a link from the Adam Audio website about the burn in of their speakers.

Yes, I saw that. Although their response doesn't exactly fill me with confidence. It just seems they are "catering" for the Audiophool/Audiodick market by caving into their beliefs (i.e.: "ADAM Audio must be top notch because they know about burn-in!"). On face value, they actually appear to be a very reputable company with a quality product but it just sounds like marketing wank. Quite smart really!

Yet, they cover themselves by stating "However, no responsibility can be taken for the correctness of this information since it always depends on both frequency and sound pressure level of the speakers usage. Furthermore, the real time a speaker needs to burn in is, to some extend [sic], always due to the specific speaker itself."

I interpret that as "If you think your speaker needs to be burnt-in, go nuts, here's some arbitrary figures. But if you're a fool and go and break something, just know that what we said might be wrong, so 'no blame'". One would think if you put something on your website or include it with your product, it would be correct?

Furthermore, nowhere in the ADAM Warranty conditions or any of their User Manuals does it mention burn-in or changes over time. On the contrary, their Warranty doesn't cover "damages caused by any use other than correct use described in the user manual".

So in other words, they can say what they like on their website and marketing material, but you won't find it anywhere supplied with your product. Nowhere do they recommend or endorse "burn-in" either.

So I stand by what I said earlier about burn-in (as a discrete process) being insignificant and if it were truly such an important factor in high quality, high cost and professional audio systems, it would be well documented, tested and have scientific backing. Until that happens, I still consider significant changes to audio response over the life of a speaking signs of a poor product. This is what the evidence (or lack thereof) indicates to me.

I'm of the belief and understanding that:
- Speakers (like microphones) do change over time as components wear and are exposed to movement.
- Is that change significant? Probably not.
- Should it have significant impact performance on the device? No.
- Is the act of "burning-in" a speaker important? No, in fact I'd go as far as saying it's a waste of time and energy.

Going back to the original post:

A pal of mine wants to design and SELL (WTF???) a device to burn in headphones...

Smart man!

He insists that high end headphones needs a burn in period before they can be said to meet their specs and deliver optimal sound quality....

Now he just made himself sound stupid again.

This i bull shit of highest degree in my humble opinion...
One thing is to build the damn device and use it for him self...but to sell it to other innocent people ? Its big time fraud in my view ?

Fraud? Probably not, if he markets it correctly and covers himself by not making scientific claims, I'm sure he would get away with it. There is a lot of money to be made off the gullible. It's probably a question of ethics more than anything.

Am i right or am i right ?

You sound more intelligent than he does.

[TMM]

Speaker driver rubber surrounds and woven spiders can loosen up a bit after some use. This only takes <1hr at a reasonable volume. This is will change the behavior of the driver mostly around it's mechanical resonance. Once it has been done, it doesn't need to be done again. Usually the manufacturers testing is extended enough that the drivers are already broken in from the factory.

Headphone drivers usually do not have discrete surrounds or spiders, that job is performed by the integral surround in the polymer cone, so they usually do not benefit from being 'burnt in'.

I'd be careful of assuming the claims of a flatter response from monitor manufactures are true.
The amount of sales BS has been increasing for years now with the advent of the home studio.

EG the KRK rp8 is known to be bass heavy.

Speaker responses are affected a great deal by the adjacent floor and walls. When exactly is a monitor speaker's response even supposed to be flat?

Exactly, saw a speaker being tested for frequency response once.
In an anechoic chamber, the speaker was high in the middle of the room on top of a pole.
Use a pulse to excite the speaker (no a freq sweep).
All to stop the room cocking up the test.

Good mixing facilities have the room specifically built for the purpose, ie. no parallel walls, no reflective materials on wall, ceiling and floor, broadband absorption panels etc.
Room is as important as the speaker, need both to be correct.

Humans with two ears are inherently better than microphones and computers at filtering out room effects from what we hear. As long as the speakers are placed close to the listener and placed to minimise early reflections it'll sound pretty good. You want the sound coming directly from the speakers to completely swamp any reflected sound, that's how monitors are intended to be used. You'd be surprised how much you can improve the sound of some monitors by raising them up 30cm off the desk, placing them on some stands and/or bringing them out from the wall at least 1 foot. Obviously room treatment helps, but that average carpet floor and drywall room is already pretty good if you position the speakers sensibly.
 
Removing the effects from measurements is a lot harder. Gating the measurement and placing the microphone near-field goes a long way. Some manufacturers do it right, some do not, and some seem to chop and change between a good measurement setup and a hopeless one. Some of the frequency response graphs i see in speaker driver datasheets are just absolute garbage. I have no idea how some manufacturers even achieve some of the responses they publish because they are so far removed from reality.

I have put together a speaker driver measurement system which only cost me a few hundred $ and is good enough to identify limitations of a speaker driver and make an objective comparison with other drivers. As you will see it is far from being an anechoic chamber, yet is still effective.
http://tinyurl.com/k4febdd

Audiophiles are very buzzword driven. Some breaking in of mechanical systems is quite common, and they love talking about breaking in. However, many speakers vary far more due to humidity, and that's just too confusing for most audiophiles, so they don't go on about it. Hygroscopic materials are still very common for speaker cones. They cause so much trouble in tropical locations you would think they might have eliminated them years ago.

This times 1000.
 
If you make a speaker cone from aluminium audiophools will describe it as sounding "harsh and metallic", even it is perfectly behaved. Similarly a speaker cone made of exotic bamboo will sound 'exotic and woody' lol.

[n45048]

Similarly a speaker cone made of exotic bamboo will sound 'exotic and woody' lol.

Oh you couldn't be more wrong! I feel sorry for you. Those sorts of speakers almost always come across as "alluring" and "ligneous" and perhaps the slightest bit "pulpy" with the proper interconnects. 

[Yago]

No one here is making assertions that these changes are massive(I don't think), just there seems good sense that they are there.
The degree and measurements are in question.

TBH you seem to be making the strongest assertions, in that this phenomenon, to all intents and purpose, does not exist.
You demand evidence, yet, unless I missed a post or two of yours, you have posted no evidence to back your opinion.

Audio sales have really sh!t on their own doorstep when you look at it.
Must be hard for genuine companies to separate themselves without being left behind in an empty maths lecture.

[n45048]

TBH you seem to be making the strongest assertions, in that this phenomenon, to all intents and purpose, does not exist.
You demand evidence, yet, unless I missed a post or two of yours, you have posted no evidence to back your opinion.

I'm really not sure what you're expecting here? (Although I do appreciate that you consider my assertions as "strong", after all, who has time for wishy-washy?) I think I made it quite clear in my post, especially towards the end what my feelings were. I based it on a sound understanding of how speakers work and the possible interactions various materials might have (non-exhaustive of course). Surely you can recognise when something doesn't "sit right". The whole concept of "burning in" speakers or headphones sounds questionable, wouldn't you agree?

I never used the term "massive". Significance depends on the context. "Significant" to a trained professional with good hearing might be a matter of +/- a fraction of a dB at a particular frequency. To put it in a different context: 10KM/hr over the speed limit in a 40KM/hr zone is "significant", but may not be on a freeway with a much higher limit.

I also never claimed to be an expert in speaker design, but I went looking for evidence to suggest that "burn-in" is a real thing that should be performed, I found none that was reputable. I work with audio engineers who know a lot more than I do and don't bother with such an exercise, so the way I view it, if it's good enough for them, it's probably good enough for the majority of us.

All these claims that suggest that "burn-in" makes a notable difference (in the positive sense) don't seem to hold much water.

[Yago]

Yes, we are singing from the same song sheet, I think you put it a bit stronger.

That's why I linked the Adam pro series, and why I said it might make sense in a professional environment, mixing etc.
Probably is at most a footnote or a disclaimer, exaggerated to sales in some companies.
That sales even plays with cognitive dissonance, reassuring the buyer against remorse... "they'll be great when they are burned in".

Like Monster blurb:
If this phenomenon is influencing what speaker you purchase, then you would be in hot water.

[dannyf]

why I said it might make sense in a professional environment, mixing etc.

Probably not: or Radioshack wouldn't have had ~70% of the studio speaker market.

[dannyf]

This whole discussion reminds of an article I read in the new york times about a small town in the liberal northeast of the US that tried to ban all tobacco sales. Most of the town folks don't smoke and consider smoking disgusting. Yet, they vehemently objected to the proposal to ban tobacco sales in their town, on the notion that however bad smoking is, it is their freedom to exercise that right to smoke, or not.

The same thing is here. Burn-in may not exist, it may not have a notable effect, it may not be wise, ....

But it is their money and if it buys them happiness, it is money well spent and it is none of anybody else's business.

Why is something so simple so difficult for the audiodicks to comprehend?

[Yago]

I thought we were wheedling through the possibility of impact and measurement, gone past the existence thing?

Never saw a "studio" speaker at RadioShack, they were just look-a-likes dressed as nearfields?

[suicidaleggroll]

Again, I'm talking about loudspeakers, not motor vehicles. Using your logic, why do Lithium battery manufacturers bother ageing batteries? Cut out the process altogether and save weeks!

I'm afraid I don't know enough about the manufacturing process of Lithium batteries to answer that.  I assume it has something to do with the consumer's inability (or unwillingness) to replicate the process in their home, so the manufacturer must do it for them, a quality that does not apply to loudspeaker break in.

Also, please link in some of the speaker manufacturers who specify a burn-in time on their products. I want to make sure I'm doing it right!

As you are well aware, there is no specific amount of time as it depends entirely on the specific driver in question and the material being used.  And AGAIN there's nothing you need to DO, right or wrong, it's a process that happens naturally as the speaker is used.  That doesn't mean you can't do anything to accelerate the process though.

If you really do want more sources, here you go.
Manufacturers:
http://www.klipsch.com/Education/breaking-in-speakers
http://www.eminence.com/2011/06/speaker-break-in/
https://www.definitivetech.com/downloads/What%20is%20Conditioning_final.pdf
http://www.paradigm.com/support/faq.php
http://www.newformresearch.com/index.php/buyers-guide/after-purchase-advice/break-in-process

Measurements:
http://www.klippel.de/uploads/media/Aging_of_loudspeaker_suspension_Klippel.pdf
http://www.gr-research.com/myths.htm


Would you like me to keep going?  I took about a minute on google to find all of these, and that was just the first page.


And here's a nice quote from the head R&D engineer at Scan-Speak:

The drive units are not "burned in" when they leave our factory. However, the Thiele/Small parameters for Scan-Speak drivers are always given for units that are burned in - for the simple reason that it makes the designer's job easier, as all speakers will end up being burned in. Speaker units will automatically burn in when they are being used. If you buy a brand new speaker system (which normally is not burned in), complete burn-in will take about a month - depending on how often (and how loud) you listen to music. During burn-in the sound quality should improve.

There is a fast way to do it and the speaker designer should burn in the units (especially the woofers) before tuning the cabinet volume, damping material and port length (vented speaker) and trimming the cross-over network.

All you need is a sine wave generator and a power amplifier. Keep the drive unit in free air. Set the frequency to about 75% of the expected free air resonance frequency of the drive unit and turn up the voltage until the cone reaches full excursion without making mechanical noise. Let it run for 5 minutes and the job is done.

Notice that only Scan-Speak parameters are given for burned in drivers. You can expect the free air resonance frequency to drop about 10% (in some cases even up to 15% - the stiffer the spider, the bigger the change) during break-in. Naturally this affects the Q-values (they go down) and the equivalent volume (Vas goes up), as it is the suspension compliance that increases.

Go figure, those predicted trends (and amounts) perfectly match those measured on the gr-research page.  It must be a global conspiracy!!!

I'm sure some audiophool will happily sell you a "special CD" for the low, low price of $79.95 which contains a "scientifically proven combination of frequencies" to make sure it's done "properly", whilst others will just tell you to play Enya really loudly. Then there are those really 'crazy' people who say it's just a load of shit and don't bother.

Just because some scam artist might try to fool somebody into buying an unnecessary product doesn't mean the entire premise is a lie.

I wish you did too! (Don't forget copies of your test microphone calibration and charactaristics data which I'm sure got burnt-in when you did your speaker the first time. It might have changed your results) 

I don't know if microphones have any kind of initial break in process, but either way the microphone was several years old and had been used many times, so it's a non-issue.

[madires]

How does the sound change when we heat up headphones while wearing (body temperature 37° Celcius)? Should I file a patent for headphone pre-heaters?

[coppice]

How does the sound change when we heat up headphones while wearing (body temperature 37° Celcius)? Should I file a patent for headphone pre-heaters?

Do you mean servants? 

[n45048]

As you are well aware, there is no specific amount of time as it depends entirely on the specific driver in question and the material being used.  And AGAIN there's nothing you need to DO, right or wrong, it's a process that happens naturally as the speaker is used.  That doesn't mean you can't do anything to accelerate the process though.

If you really do want more sources, here you go.
Manufacturers:
http://www.klipsch.com/Education/breaking-in-speakers
http://www.eminence.com/2011/06/speaker-break-in/
https://www.definitivetech.com/downloads/What%20is%20Conditioning_final.pdf
http://www.paradigm.com/support/faq.php
http://www.newformresearch.com/index.php/buyers-guide/after-purchase-advice/break-in-process

Measurements:
http://www.klippel.de/uploads/media/Aging_of_loudspeaker_suspension_Klippel.pdf
http://www.gr-research.com/myths.htm


Would you like me to keep going?  I took about a minute on google to find all of these, and that was just the first page.

That's because it's largely unnecessary. No one is disputing that materials change with use and over time, that's a given. The argument here is the whole theory of "break-in" (or "blossoming" as one of your linked sites called it) and whether such an effect has a positive effect on the audio.

Let's set aside any negative effect that these changes might have for a moment and analyse this (as you won't get an audiophool telling you that "break-in" will be detrimental, it's always for the better, right?)

I read all of the links you posted. Here is my analysis:

Klipsch:
"components may particularly benefit from a break-in period"
"Either way, it’s possible that you’ll notice an improvement."
They don't seem too sure (or don't want to make claims that they can't substantiate). But I'm sure their customers have experienced "dazzling" improvements. Largely psychological I suspect.

'Big Tony' from Eminence: Wow, this guy seems really sure of himself! And why wouldn't he be? His job title at Eminence is "Tech Support & Tone Guru", impressive! I take these sorts of 'news' articles with a grain of salt, but our 'tone guru' tells us that "the sonic results you will hear are an increase in overall warmth, slightly deeper/fatter lows, and warmer/smoother highs". Mmmm... sounds like marketing wank to me. I find it hard to accept what he's saying as fact after reading that.

Definitive Technology: Now this looks promising. Some actual data and a reference to a test standard for a change. But all this paper basically confirms is that the material will undergo some changes (which we knew). It doesn't mention anything about what effect this has on audio, they just mention "improve" and "peak performance".

Paradigm: Great speakers, I've used them before. Again, these guys make the claim that their speakers will sound better, but don't say how. They just recommend you 'use' your speakers before actually 'using' your speakers... what the?

NewForm Research: Amongst some of their marketing wank they claim "There are however, some clearly defined effects on break-in time" but don't actually specify what these "clearly defined" effects are. They even claim that the performance of your cables will change! 

Klippel: A very comprehensive document on mechanical ageing (which again, no one here seems to be disputing). It says nothing about how these changes effect audio.

GR Research: Their tests basically go to show that there is some softening of the material (again, we know). Interestingly, they also state "This objective data showing changes in the T/S parameters as the suspension loosens up does not prove noted subjective differences in the perceived output, or how a speaker sounds, but does prove that there is something more taking place than getting used to the sound."


After all that, I'm still sticking to my guns in that any perceivable changes in audio "quality" can be explained by other means other than the speakers actually improving. I suspect that explanation is largely psychological.

The term "break-in" could be used to describe the softening of the material. But some audiophool has taken it and applied it to a correlation in performance increase. We must remember that correlation does not imply causation.

[Mark Hennessy]

After all that, I'm still sticking to my guns in that any perceivable changes in audio "quality" can be explained by other means other than the speakers actually improving. I suspect that explanation is largely psychological.

The term "break-in" could be used to describe the softening of the material. But some audiophool has taken it and applied it to a correlation in performance increase. We must remember that correlation does not imply causation.

I don't know if you've read my earlier posts on this topic, but essentially "break in" refers to the resonant frequency of the drive unit falling during the first use.

Depending on how much production testing the manufacturer has done, and depending on the exact materials used, and also on the use during "break in", this easily-observed change in Fs will asymptote after some minutes, hours or days.

None of that is mysterious or beyond doubt. There is plenty of evidence to demonstrate that this happens. I have published some of my own, and so have plenty of other folk.

Of course, a drive unit has many other parameters, but Fs - a product of suspension compliance (and mass) - is a convenient metric to observe. Once Fs has settled, one can measure the parameters of the "broken in" drive unit with confidence.

Once a designer is in possession of all these parameters, an enclosure can be designed around the unit.

The enclosure (hence, bass tuning) will depend entirely on these parameters. Agreed?

So, if you designed an enclosure based on data collected on a brand-new unit, you would end up with a very different enclosure. It would have a different volume, and different port tuning. It would only be the optimum enclosure for the first few minutes of operation.

Or, to put that another way, the box is designed for a drive unit that has been exercised and is performing according to its long-term specification. The brand new drive unit is not going to be a good match for the supplied enclosure. The bass tuning will be incorrect. But once Fs (hence all the other parameters) have settled, then the box and the drive unit will match as the designer intended.

So, by any objective measure, there will be a performance increase after run-in. It can be measured and quantified. It might be subtle; it might be significant - it depends on the particular drive unit, and it depends on the box tuning. For example, a simple sealed box is fairly forgiving - a ported box could be less so.

How audible it might be is clearly another matter. It's one of those tricky "it depends" problems. But sometimes, it can be heard. Been there, done that.

I speak as an engineer who has experience in this area, and because I know the mechanism, I can speak in engineering terms about the effect. But our audiophile friends lack this knowledge, so of course they will pick words and phrases from their world. And many engineers will be quick to dismiss their subjective reports as "audiophool nonsense", because that's easy and lazy - no intellectual effort required. But while a lot of what audiophiles claim to hear is very obviously the product of an over-active imagination - fuelled by the hi-fi press, marketing material and internet forums - this is an exception. Data exists. It is real. The only variable is the extent to which is can be measured and heard.

Of course, in public, many manufactures will use imprecise language. They have to be extremely careful about what they say, and what they might give away to their competitors and critics - it is an incredibly difficult market for the majority of small and medium-sized companies that make up the loudspeaker market (in the UK at least). These companies are selling products to audio enthusiasts who are largely non-technical, so they must write in a language that they can understand. And what they publish must be perceived to have a positive outcome - primarily it will be intended to reassure their customers in some way. It's not like they are selling test gear to electronics engineers.

And yes, I do agree that there will an amount of psychoacoustics at play as the owner gets used to the new loudspeaker - this is usually the reason behind the claims of many hundreds of hours needed. I said as much in my first post in this thread. This usually happens when someone has made the wrong choice but is refusing to admit it to themselves - a surprisingly common human trait that isn't restricted to audio.

[n45048]

This usually happens when someone has made the wrong choice but is refusing to admit it to themselves - a surprisingly common human trait that isn't restricted to audio.

Absolutely. I think even Dave said that "no one likes to be made a fool".

[janengelbrecht]

And people speak of big loudspeakers all the time.....the subject was in fact headphones With some very different physical aspects as other pointed out