Speaker Breakin Article

[Biscokid]

By Danny of GR Reserch.
[url removed - old news]

what do you guys think of this article?

 

[Tom Andry]

This is what we think of it.

 

[emorphien]

This is what we think of it.

I breezed both articles briefly, the one posted by the OP seems to claim actual measurements (issues of validity aside) while ours seems to be mainly based on theory and modeling.

What little experience I've had gives me an opinion slightly between these two articles but I am a little curious. I'll probably see if I can do a literature search on more articles on this around my more pressing work issues. Neither article seems substantiative enough to me.

 

[Biscokid]

This is what we think of it.

We know what "we" think. I am asking about this article which was published after "We's"

 

[krabapple]

Crux of the matter has two aspects. The first one relates to this Audioholics conclusion:

But once a driver is past the initial suspension-stretching break in, do further changes occur?

Regardless of how completely broken in a driver may be, while under operating conditions many well-known & understood mechanisms come in to play that affect several of a driver’s measured parameters, including suspension mechanical compliance.

When under normal operating conditions, its not at all unusual to see in a driver that has already been broken in a further 5% to 20% drop in Fs, due largely to an increase in the mechanical compliance of driver’s suspension. In this case, typically it’s the temporary elastic deformation of the surround that’s the cause of the increase in driver compliance.

Cease stimulus and the driver’s compliance will return – in most cases within seconds or minutes depending upon surround design, material composition, ambient temperature and so on - to its pre-stimulus value; the compliance changes are temporary. So too are the changes that occur in all the other driver parameters that are effected by compliance, hence the changes in Fs, Vas, etc.

The OP's article appears to show persistent changes in compliance of a 5.25" woofer after cooldown following a long 'break in'. That is, the compliance goes back down, but it doesn't go back down to the level of the 'early' break-in. Compare the 10-sec/manually broken in values (which I am going to assume equates to 'fully streched' condition as per the Audioholics definition of initial break-in) with the 20 hr values after cool-down

after manual stretch and 10 sec of 50 Hz sine wave, followed by cooling:

!• ! Fs 54.2135 Fs
!• ! Added Mass 25.1519
!• ! Added Mass 25.0000
!• ! Diameter 110.0000
!• ! Re 5.6000
!• ! Rms 1.0383
!• ! Qms 2.2495
!• ! Qes 0.3978
!• ! Qts 0.3380
!• ! Cms 1.2569
!• ! Mms 6.8570
!• ! BL 5.7342
!• ! VAS 15.8505
!• ! dBSPL 90.0498
!• ! L 1kHz 0.3234
!• ! L 10kHz 0.1819
!• ! SD 0.0095
We can see that the 10 seconds of hard play
with the 50Hz sine wave had no lasting effect
on the compliance [compared to manual stretch]. The Fs went back up. The
Vas stayed relatively the same, and the Q factors
went back up slightly. By the numbers this
one will hit a -3db of 62Hz.

after 20 hrs of play, followed by cooling for 'several hours':

!• ! Fs 50.4711
!• ! Fs Added Mass 23.2400
!• ! Added Mass 25.0000
!• ! Diameter 110.0000
!• ! Re 5.6000
!• ! Rms 1.0358
!• ! Qms 2.0595
!• ! Qes 0.3707
!• ! Qts 0.3141
!• ! Cms 1.4782
!• ! Mms 6.7269
!• ! BL 5.6771
!• ! VAS 18.6419
!• ! dBSPL 90.1291
!• ! L 1kHz 0.3249
!• ! L 10kHz 0.1804
!• ! SD 0.0095
These changes are consistent with every
other time that I have measured a drivers parameters
before and after burn in. This woofer
still has a way to go though and a slight
amount of change still ahead. 20 hours is not
enough to reach a settling point.
Since this woofer was first pulled from the box
the Fs has dropped by over 6Hz. Vas has increased
by over 4 liters, and the Qts has
dropped from .3581 to .3141.

More to the point (because after all, the Audioholics article concurs up front that there will be an 'initial' break-in change in compliance) in Richie's test, compared to 'initial break-in' numbers, Fs was down about 4 Hz , Vas up about 3 litres. Does that amount to a significant change? It's more than the change in Fs and Vas seen when comparing 'oput of box' to stretch/50Hz/cool (about 3 Hz and 2 litre, respectively). Does it amount to a hill of beans in a real-world driver + enclosure? One of Richie's pals even notes this with the caveat

Granted that the effect on the in-box measured curve,
due to break-in / burn-in, may or may not be
significant, depending on the box.

(And can someone please calculate the -3 dB point for the 20-hour data?)

Would it perhaps be interesting to see the numbers after, say, 10 minutes of normal play? The test points jump from 10 sec to 20 Hrs with nothing in between, yet it's here that most of the change seems to occur. Also, how do these numbers relate to driver-to-driver tolerances? Btw, I did not find his claim that further signficant changes took place beyond 20 hrs convincing, based on his numbers.

The second matter is audibility of the changes, which was not tested.

 

[Audioholics]

We know what "we" think. I am asking about this article which was published after "We's"

It may have been republished - but this is the same thing that was on the GR site before. Search the forum for the old thread. He showed some measurements but never takes into account the speaker as a system - which matters a whole lot when discussing the audibility and real efects of break-in.

Bottom line is that 'extended' speaker burn-in remains a system whereby manufacturers can get unknowing consumers to go through their return period and grow accustomed to their speakers. They never talk about speaker burn-out - whereby the speakers wear down and need to be replaced (of course, there I go again giving them more ideas).

We're not a manufacturer - as such we really have no vested interest either way. It's bunk and it's been debunked. Any further work on our part is a waste of time for the handful of people who still buy into this stuff.

 

[krabapple]

It may have been republished - but this is the same thing that was on the GR site before. Search the forum for the old thread. He showed some measurements but never takes into account the speaker as a system - which matters a whole lot when discussing the audibility and real efects of break-in.

Bottom line is that 'extended' speaker burn-in remains a system whereby manufacturers can get unknowing consumers to go through their return period and grow accustomed to their speakers. They never talk about speaker burn-out - whereby the speakers wear down and need to be replaced (of course, there I go again giving them more ideas).

We're not a manufacturer - as such we really have no vested interest either way. It's bunk and it's been debunked. Any further work on our part is a waste of time for the handful of people who still buy into this stuff.

You did, however, say that there was going to be a follow-up article from Tom. Is that cancelled now?

 

[Resident Loser]

What did...

...the alligator say to the caiman?

That's a croc...

Some mechanical things do indeed break in...however, things like speaker surrounds, etc. do it quite rapidly...once they arrive at stasis or elastic eqilibrium or whatever, the only place to go is down...as in breakdown...

As I recall, there are a few manufacturers who provide individualized FR plots with each unit they sell...so the question arises, how could they guarantee those specs to be accurate if further use will somehow change them?...I doubt they do a 500hr. burn...

It seems as though most burn-in/break-in periods are just long enough to negate any return privileges the listener might have...

jimHJJ(...the only thing that breaks-in are your ears...)

 

[Biscokid]

I personally have never experienced any sort of break-in and I own an amp whose maker has four pages on it in the book. On a side note I also take the articles here with a grain because they have their beliefs and thats that.

 

[mtrycrafts]

The second matter is audibility of the changes, which was not tested.

This is what this whole issue is about, audibility
You can certainly measure two wires of the same brand, one 10 ft long, the other 20ft. The longer one will have twice the numbers of the shorter one.
But, is that audible? Not.
Nousaine couldn't detect an audible change in drivers.

 

[mtrycrafts]

I personally have never experienced any sort of break-in and I own an amp whose maker has four pages on it in the book. On a side note I also take the articles here with a grain because they have their beliefs and thats that.

I think the articles here have empirical data behind them, and that's that too.
One day, perhaps some DBT data as well

 

[Biscokid]

Are you saying the article I posted does not have data?

 

[gene]

You did, however, say that there was going to be a follow-up article from Tom. Is that cancelled now?

Not Tom, Mark Sanfilipo and its still on his plate though not a priority right now.

We have another guy working on articles about driver mechanics/materials that should prove interesting as well. Stay tuned...

 

[Danny Richie]

I breezed both articles briefly, the one posted by the OP seems to claim actual measurements (issues of validity aside) while ours seems to be mainly based on theory and modeling.

You are correct. The information that I posted contains real measured data that is consistent with the measurements made by every other driver designer or manufacturer.

However the data posted here at this site is based on nothing more than an assumption. No real data to support the theory is given.

Bottom line is that 'extended' speaker burn-in remains a system whereby manufacturers can get unknowing consumers to go through their return period and grow accustomed to their speakers. They never talk about speaker burn-out - whereby the speakers wear down and need to be replaced (of course, there I go again giving them more ideas).

We're not a manufacturer - as such we really have no vested interest either way. It's bunk and it's been debunked. Any further work on our part is a waste of time for the handful of people who still buy into this stuff.

Clint, That is total nonsense, disrespectful, and insulting to the professionals of this industry.

You guys really need to yield a little more respect to those of us that take the time to educate you on this subject by documenting real measured data. If you can't take the word of those of us that design and build drivers for a living, then please at least conduct these test for yourselves. The information you have posted on your site here is false, misleading, and a disservice to the audio community.

 

[Audioholics]

No, Danny. You have proven time and time again that you have an agenda and we simply don't have the time to front burner this article just yet. Your generalizations are astounding - someday you'll need to show us the interview data of "every other driver designer or manufacturer" who shares your beliefs.

Loudspeakers DO break in. It simply doesn't take 600 hours as some would have everyone believe, and the audible effects are more than questionable. We apologize that our first round of measurements wasn't up to your satisfaction - and yes, we did take measurements before modeling the results - this keeps getting ignored or overlooked.

Bottom line is that only poorly designed drivers would change response audibly over time.

 

[gene]

You guys really need to yield a little more respect to those of us that take the time to educate you on this subject by documenting real measured data.

Of course this is coming from a company that believes speaker cables need 50hrs to "burn in".

http://www.gr-research.com/components/wire.shtm

Burn in time: These cables do need at least 50 hours of burn in time to settle in and smooth out. We highly recommend this before evaluating them as their character will change some from the moment that they are first played.

Personally I think if only manufacturers would lube up their drivers with kosher chicken fat prior to shipping them, there would be no argument for break in

 

[Tom Andry]

Personally I think if only manufacturers would lube up their drivers with kosher chicken fat prior to shipping them, there would be no argument for break in

Mmmmmm.... chicken scented speakersssssssssss...........

 

[corysmith01]

The second matter is audibility of the changes, which was not tested.

That's always been my question, and why I'm so puzzled over this exists/doesn't exist debate. If it occurs, can you hear it? Does it produce a detectable change in sound? Is there an audible change? If not, isn't the whole debate moot?

 

[Danny Richie]

No, Danny. You have proven time and time again that you have an agenda and we simply don't have the time to front burner this article just yet.

The only agenda I have is that people should not be falsely led to believe that this is some sort of scam (like you make it out to be).

Your generalizations are astounding - someday you'll need to show us the interview data of "every other driver designer or manufacturer" who shares your beliefs.

You call it "beliefs" I call it "known industry fact". As you can see other industry professionals have sent statements that their measured data shows the same results.

Loudspeakers DO break in. It simply doesn't take 600 hours as some would have everyone believe,

I am not making claims that it takes that kind of time. However in some applications (like some line source designs) it can take several hundred hours of normal play. Suggesting as your web site does here that it takes only a few seconds is far from the truth.

and the audible effects are more than questionable.

They are only questionable to some people. I can't guarantee that everyone or that anyone will notice the audible effects. The systems that you guys use to review products with is not exactly the kind of system that will allow one to notice these changes. For some of us the audibility effects of burn in are quiet clear.

We apologize that our first round of measurements wasn't up to your satisfaction - and yes, we did take measurements before modeling the results - this keeps getting ignored or overlooked.

What difference does it make if you only take the "Before" measurements and don't bother to take any after that? You might as well have just taken published specs from something and made the same assumptions.

Bottom line is that only poorly designed drivers would change response audibly over time.

This is absolutely false! All woofers will show this same type of compliance change as a result of the same amount of play time.

Of course this is coming from a company that believes speaker cables need 50hrs to "burn in".

So you discriminate against my measured data because I can also hear?

I would love to have you guys come over for a visit some time. We can listen to burned in verses non-burned in speakers together. When would be good for you guys?

 

[emorphien]

That's always been my question, and why I'm so puzzled over this exists/doesn't exist debate. If it occurs, can you hear it? Does it produce a detectable change in sound? Is there an audible change? If not, isn't the whole debate moot?

That's a bit of a problem with a lot of the test measurements and theory as discussed. On the one hand you have theoretical discussion and then a heavy-handed dismissal and on the other you get people taking measurements and inferring things from them without much in the way of valid listening tests.

Everyone goes in with their own opinion, and often the result is a less than concrete or scientifically valid conclusion.