Do Audio Speakers Break-in?

[Andretti60]

I've provided evidence. Look at it. It's not patronizing. I can tell you haven't so it was a well meant advice.
I won't comment on your elastic bands. What an argument..

I saw two links of yours.
The first is a video of Paul from PSAudio who replies to questions from (not so how much valid) email, he makes those videos for fun, in a goofy way, adding small talk about cats and dogs, and then expressing “his” personal ideas with no objective scientific proof. PSAudio is famous to build ridiculously expensive and completely useless gadgets.
The second is a YouTuber I don’t know anything about, who shows parameters changes between a new driver and another same one apparently been broken in, that is not a valid comparison because he compares two “different units”, the results I bet remain within the component tolerance. If I had to believe to YouTube, Earth is flat and governed by reptlians.

 

[pablolie]

Drivers have dramatic changes with temperature.
...

Does this mean that all speakers suck and have uncontrolled tolerances in active duty? I kind of doubt that it is "dramatic" and sound characteristics change audibly. I have zero doubt some aspects change over time and with temperature... but also think that is taken into design considerations and stay well under any audibility levels. Otherwise I am not sure why we bother to even discuss this audiophile stuff. I personally have never ever heard differences when I listen to music for a long time.

 

[Deleted member 48726]

Drivers have dramatic changes with temperature.
This has a significant impact on their actual performance.

Voice Coil Temperature

www.klippel.de

While the voice coil heats and cools in seconds, the magnet slowly stores the heat for quite a long time. 50C delta is actually the low end of realistic.

B&O publish some measurements of their magnet temps and the predicted VC temps while run very hard:

B&O Tech: Thermal Compression Compensation

#9 in a series of articles about the technology behind Bang & Olufsen loudspeakers Recipe for`Befuddled Speaker Enthusiast´ Makes: One individual with reduced faith in louds…

www.tonmeister.ca

This B&O test is pretty extreme.

The delta of 50 K was in a ambient temperature, not magnet and / or voicecoil. -Right? Which of course reach higher than ambient temperature fast when worked hard.

 

[Deleted member 48726]

I saw two links of yours.
The first is a video of Paul from PSAudio who replies to questions from (not so how much valid) email, he makes those videos for fun, in a goofy way, adding small talk about cats and dogs, and then expressing “his” personal ideas with no objective scientific proof. PSAudio is famous to build ridiculously expensive and completely useless gadgets.
The second is a YouTuber I don’t know anything about, who shows parameters changes between a new driver and another same one apparently been broken in, that is not a valid comparison because he compares two “different units”, the results I bet remain within the component tolerance. If I had to believe to YouTube, Earth is flat and governed by reptlians.

Try again. -With the reading that is. Not the gnarly remarks. Seems like you really can't control those.

For a self-titled objectivist you sure use a lot of subjective and emotional guided words and phrases. -Unwarranted insults, generalizations, bets.

If I had to believe to YouTube, Earth is flat and governed by reptlians.

-Sounds like something a reptile would say.

 

[Andretti60]

…
For a self-titled objectivist you sure use a lot of subjective and emotional guided words and phrases. -…

As a non-native English speaker, I am taking that as a compliment

 

[Deleted member 48726]

Does this mean that all speakers suck and have uncontrolled tolerances in active duty? I kind of doubt that it is "dramatic" and sound characteristics change audibly. I have zero doubt some aspects change over time and with temperature... but also think that is taken into design considerations and stay well under any audibility levels. Otherwise I am not sure why we bother to even discuss this audiophile stuff. I personally have never ever heard differences when I listen to music for a long time.

Well, I'm sure B&O knows their stuff and it is interesting. Makes sense though, as VC temperature rises it's impedance changes as well.

This plot is interesting. VC delta-temp. vs. sensitivity on the woofer--> First time I have seen such a graph.

 

[MAB]

Does this mean that all speakers suck and have uncontrolled tolerances in active duty? I kind of doubt that it is "dramatic" and sound characteristics change audibly. I have zero doubt some aspects change over time and with temperature... but also think that is taken into design considerations and stay well under any audibility levels. Otherwise I am not sure why we bother to even discuss this audiophile stuff. I personally have never ever heard differences when I listen to music for a long time.

Yeah, agreed. I think the B&O example is extreme, since they are advertising their advanced compensation for these effects. Look at those magnet temps in their measurement, the midrange magnet can fry an egg! Most manufacturers (JBL, Neumann, etc.) seem to use DSP these days to limit the ability to operate the driver before it compresses and distorts unacceptably from my understanding, so the B&O method seems more sophisticated.

But thermals in drivers matter if you play them hard for any extended period of time, especially PA and (ahem) car-audio, where I think valid efforts go into minimizing thermal compression and distortion. Like a JBL:

Lots of fancy stuff, some fluff, some very substantial I think.

For me, I can barely survive an entire song at even half my system's max!
So unless someone likes it really loud (and listens critically when it is loud!), most good drivers seem to not change audibly.

 

[MAB]

Well, I'm sure B&O knows their stuff and it is interesting. Makes sense though, as VC temperature rises it's impedance changes as well.

This plot is interesting. VC delta-temp. vs. sensitivity on the woofer--> First time I have seen such a graph.
View attachment 272451

Yes. They were running that speaker so hot to make a point about their advanced thermal compensation wizardry! It's interesting.
Klippel has some great stuff on distortion in general.

https://www.klippel.de/fileadmin/klippel/Files/Know_How/Literature/Papers/Klippel_Nonlinearity_Poster.pdf

And thermal model of a driver:

https://www.klippel.de/fileadmin/klippel/Files/Know_How/Application_Notes/AN_19_Nonlinear_Thermal_Parameters_%28Convection%20Cooling%29.pdf

My goal in life is to get gear good enough I can stay well away from these temperature and excursion and other non-linear regimes!

 

[solderdude]

I've had a couple of drivers that changed after burn-in (and or usage).
Mostly tweeters but also an occasional woofer and even 2 headphone drivers.

The tweeters changed sound dramatically and went from sounding as specified to giving no sound at all, which is what I call a dramatic change.
I have had woofers that after a burn-in (playing quite loud for a prolonged period, often well after the break-in period) that also changed dramatically and started to distort audible and even changed their compliance and became unusually 'stiff' so only some 'crackling' sounding upper midrange came out.
The same thing happened with some headphone drivers which changed dramatically.
From distorted lows to no sound at all.

Do mechanical devices change during usage ? Of course, could that be audible ? of course but could in specific cases in lab test conditions is not the same as does in all cases.

Does wear and tear exist ? Oh yes.
Is wear and tear burn-in ? I think wear and tear is not burn-in. Burn-in is a relatively very short period prior or during first usage in which parameters settle close to the expected/designed parameters. Nobody designs something so it only starts to perform optimally after weeks, months of years of usage.

Does temperature make a difference ? Of course it does, for home hifi the range will be just 20 degrees C. For headphones also used as ear warmers and worn in hot summers as well. Sure that'l make a difference. The foam inside ear pads alone can react very different alone. Will people notice substantial differences and remember how the same song sounded half a year ago in the cold at maybe a different level ?

Is pro usage different from home usage? You bet it is.

Can 20Hz at 110dB produce an audible 20kHz harmonic ? yes, maybe it can but am sure even if that harmonic (and the 2nd to 99th are not there which is a tall order) even at 100dB SPL I cannot hear but would be able to measure. Has nothing to do with burn-in but is a perception thingy.

I agree with some of the things @Thorsten Loesch talks about but the thing with burn-in is that changes occur slowly in the same time period humans can get used to a sound signature. Not weeks or months. A lot of the 'things' people (claim) to hear and ascribe to 'burn-in' are, more often than not, be blamed on owners getting used to a sound 'signature' rather than what they believe is 'burn-in'.

A confounding difficulty is that while burn in exists (the period in which the device starts to operate close to designed parameters) it is very hard to prove as the difference is not instant and you cannot go back to the initial state and compare.
Using 2 devices from the exact same (driver) production run and measuring them directly for all specs (in which both drivers receive a part of the break-in period) and then break-in one of them and measure it over time is the only real evidence. It would be very hard to compare those by ear because of practical issues.

The practical question is not whether or not mechanical components (drivers mostly) change from the moment they were created to normal every day usage.
They will. Nobody will deny that.
That there will be changes due to wear and tear (which I would not call burn-in or break-in) also is not denied here. We all (should) know this occurs.
The question is whether or not this is audible and to who in what circumstances.
The biggest variable in this case is more likely to be perception than an actual change in the devices.

Can it be measured ? Sure
Does it happen ? sure
Will it be audible ? might or might not.
Is perception of owners trustworthy ? Some believe it is others do not.
Yet... all the 'I can hear improvements (mostly not getting worse) is where all reports of 'burn in over weeks, months, even years come from is just that. None of the ones that 'report' long term 'burn-in' can actually go back in time and memory is flawed.

Yes, burn-in and break in is reality. Audibility is perception and is well... more suspect than not.
The question is whether or not one relies on their own findings or is skeptical about long term memory.

 

[Thorsten Loesch]

Yes, burn-in and break in is reality.

Yup, but just because it is real it does not mean it is reliably audible (or not).

Audibility is perception and is well... more suspect than not.
The question is whether or not one relies on their own findings or is skeptical about long term memory.

I tend towards scepticism.

But I also feel that running a speaker (or indeed headphones and audio electronics) for 48 Hours with pink noise at high but safe levels before listening is not much pf a chore and additionally it screens out "early failures" while still in the seven day no quibble return period (if you get longer, great).

And if after "burn in" you don't like the sound it's fairly safe to state "burn in" is not the issue.

Just saying.

Thor

 

[Mulder]

It is my experience that recently acquired basically good speakers or headphones are perceived to sound better after a couple of weeks.
I believe this is entirely due to gradually adapting and learning to appreciate a new sound signature.
The funny thing is that I feel it's the other way around with HiFi which is heavily coloured and maybe not really that good.
These can often sound seductive straight away, but after a couple of weeks you tire of the sound signature.

 

[solderdude]

But I also feel that running a speaker (or indeed headphones and audio electronics) for 48 Hours with pink noise at high but safe levels before listening is not much pf a chore and additionally it screens out "early failures" while still in the seven day no quibble return period (if you get longer, great).

Yep, that's what a burn-in period (at least for electronics) is good for.
Sifting out units that would fail rather sooner than later. This what I use the word 'burn-in' for and use the word 'break-in' for mechanical devices that are not meeting specs yet when rolling off an assembly line.
Quite common in the non consumer world to do this.
This, however, is as you state no guarantee the device will have good longevity and quality.

200Hrs or 1000 hours to get 'maximum sound quality' is nonsense and IMHO just something manufacturers/sellers use to state to get people to 'adjust' to devices they had high hopes for but initially don't seem to deliver.

 

[AaronJ]

200Hrs or 1000 hours to get 'maximum sound quality' is nonsense and IMHO just something manufacturers/sellers use to state to get people to 'adjust' to devices they had high hopes for but initially don't seem to deliver.

To also create an escalation of commitment which may be an even more powerful motivator than adjusting.

 

[Thorsten Loesch]

200Hrs or 1000 hours to get 'maximum sound quality' is nonsense

If there is material burn/break in and this happens at very low playback levels with music, this quite possible.

Hence my preference for "forced" or "accelerated" burn/break-in. I don't like to wait that long.

Thor

 

[Deleted member 48726]

Yep, that's what u burn-in period (at least for electronics) are good for.
Sifting out units that would fail rather sooner than later. This what I use the word 'burn-in' for and use the word 'break-in' for mechanical devices that are not meeting specs yet when rolling off an assembly line.
Quite common in the non consumer world to do this.
This, however, is as you state no guarantee the device will have good longevity and quality.

200Hrs or 1000 hours to get 'maximum sound quality' is nonsense and IMHO just something manufacturers/sellers use to state to get people to 'adjust' to devices they had high hopes for but initially don't seem to deliver.

Maybe calling it nonsense is a stretch. The truth often is somewhere in between. It's good to be sceptic in a healthy amount. Maybe Thorsten have a point in that it can take longer with lower SPL so to be safe (and maybe also to limit the returns) some manufacturers sales department have a multiplying factor on the engineers' advice..

 

[Thorsten Loesch]

some manufacturers sales department

Please don't get me started on sales & marketing departments...

Thor

 

[cavedriver]

Well, I'm sure B&O knows their stuff and it is interesting. Makes sense though, as VC temperature rises it's impedance changes as well.

This plot is interesting. VC delta-temp. vs. sensitivity on the woofer--> First time I have seen such a graph.
View attachment 272451

If this is real behavior of an actual driver and differences of +/-1.5 dB are detectable by an average listener (is that the going number?), then shouldn't it be easy to prduce a measurable change in speaker behavior simply by measuring it cold and then hot? Something doesn't seem right here...

EDIT: reading MAB's post above I guess the problem is that +40 or +60 degrees is a lot of heat and not realistic in a home audio application because the listener would be deafened if they played the system at that level long enough to get it to that temp? But still, if the resolution of the Klippel is +/-0.5 dB (it is at least that, isn't it?), then the effect should still be measurable fairly easily. Just don't stand near the speaker during "heat-up"

 

[YSC]

If this is real behavior of an actual driver and differences of +/-1.5 dB are detectable by an average listener (is that the going number?), then shouldn't it be easy to prduce a measurable change in speaker behavior simply by measuring it cold and then hot? Something doesn't seem right here...

Amirm’s kh80 dsp did showed a cold and hot climate change in FR a lot more than any break in would do

 

[fpitas]

If this is real behavior of an actual driver and differences of +/-1.5 dB are detectable by an average listener (is that the going number?), then shouldn't it be easy to prduce a measurable change in speaker behavior simply by measuring it cold and then hot? Something doesn't seem right here...

It happens, but it's more of a pro-audio thing. Domestic use typically doesn't feed enough average power to make a big difference.

 

[Deleted member 48726]

If this is real behavior of an actual driver and differences of +/-1.5 dB are detectable by an average listener (is that the going number?), then shouldn't it be easy to prduce a measurable change in speaker behavior simply by measuring it cold and then hot? Something doesn't seem right here...

EDIT: reading MAB's post above I guess the problem is that +40 or +60 degrees is a lot of heat and not realistic in a home audio application because the listener would be deafened if they played the system at that level long enough to get it to that temp? But still, if the resolution of the Klippel is +/-0.5 dB (it is at least that, isn't it?), then the effect should still be measurable fairly easily. Just don't stand near the speaker during "heat-up"

I've played for like 45 min. semi loud. Didn't measure how much. Feeling the dust cap I could feel the heat. Must have been around 60 degr. C in the voicecoil. Live rock. All eight woofers and all four mids were warm to the touch.
Have you felt the top of an ab class amp when just idling? That's between 30-60 watts of heat. It's not unrealistic to measure high temperatures in the VC itself.
If you feel the magnet on a sub after a movie I bet its warm as well.
That's literally the output power converted to heat.