Speaker break in - is it real?

[billfitzmaurice]

More with some drivers than others. MartyH had to redo the xover on his Copper project after about a year due to breaking in.

I always break in drivers before testing them in a prototype cab. Using accelerated break in it only takes overnight, and for the most part it just gets the driver to their published specs. Manufacturers measure specs after break in, not before. I'm not aware of any who break in drivers before shipping them, as that would increase their cost.

[tomzarbo]

Billet,

I've wondered how substantial break-in really is as well; I'm probably not too qualified to answer this question since I've done no testing on the subject, but I'll share what I think about it.

I like putting a new driver on the DATS, then flexing the cone several dozen times and watch the Fs drop by 6 or 7 Hz from the initial sweep. Often the Fs will rise again within a few minutes; I think over time the change would set-in and become permanent.

Even though the change shows up most in the lower bass range, or rather it's easier to see in the Fs spec, I believe it must alter the sound of the upper bass frequencies/lower midrange to some degree.
No, I can't prove it, and I don't pretend to understand it... but....I can listen to half a dozen speakers I've built with fairly flat frequency response in the same position in the room... and boy, they all sound different. Very similar squigglies on the FR graph, but different sounding for sure...something that's not necessarily measurable on a FR graph like I would think it would be.

A woofer's suspension that loosens up considerably through large movements from break-in would seem to me to have a more drastic affect on upper bass/midrange frequencies...for example, if a dome midrange suspension loosened up to the same degree or percentage as a 6" woofer's does after break-in, I would expect a noticeable change in FR. I'm not sure, but I kind of doubt that a dome midrange suspension loosens up all that much, but since a 6" woofer's suspension does -- or can break-in quite a bit from new, I think it's 'possible' to hear things smooth-out enough to possibly notice given what I just stated.

Anyway, no science here, just my ramblings, and I'm likely wrong, but I think there are possibly factors aside from a frequency response graph at play when it comes to 'break-in' on some speaker drivers. Just my overpriced two cents.

TomZ

[Wolf]

From what I've read, not talked to him personally, yes the tuning was affected as well. Since the drivers broke in it shifted the tonal balance of the speaker to be bright rather than neutral, and IIRC, he had to at least adjust the padding on the tweeter. I don't know how much he had to do, as he never updated the thread to post the final, again IIRC, but he was working on a 3-way version.

Edit: I went 14 pages back in search for it, but did not find the build thread. It was quite a while ago.

Later,
Wolf

[PWR RYD]

Did Marty redo the XO?  I thought he had to adjust the port length on the MLTL because the bass became boomy.  I may have misunderstood what he and Paul were saying at dinner that night in Iowa though.

[Wolf]

More with some drivers than others. MartyH had to redo the xover on his Copper project after about a year due to breaking in.

Wolf

[Billet]

I have definitely noticed woofers that break in dramatically in the first hour or less. They have minimal bass out of the box, then after a little bit...normal... After that, I'm not so sure. I think that the mind gets used to a new sound over time, this makes comparisons difficult. Maybe the speakers continue to loosen up also. Even cones flex and might possibly soften up over time. It is probably both speakers and ears changing. I did not expect any conclusive answers, I am more curious what others experiences are.

[PWR RYD]

But I thought that full range drivers named after some dude takes 500 hours to really break in and sound proper 

[Paul K.]

Bill's comments in Posts #3 and #6, especially Post #6, makes the most sense, both technically and logically. What Fred said in Post #5 is also true, but the degree to which the materials breaking in effect the sound and how long it takes is questionable.
Paul

[billfitzmaurice]

There are convincing arguments that poo poo the break in theory

They're not made by transducer engineers.

so I guess it's all in my head (ears)

Maybe 90% between your ears, 10% what they actually hear, as born out by the only method that really determines how much effect break in has: measured results.

 

[fdieck]

Why is even a question to some?  Yes they break in. The spiders loosen up after flexing as do the surrounds. This is why Fs is lower after a few hours of use. The glue and voice coil former undergo thermal cycling. anyone who has taken a course in material science would be mystified as why there would be any controversy on this subject. Listen to a new drive and one with  a hundred hours of playing and make up your mind free of what anyone tells you. 

[scary]

I have the same question! There are convincing arguments that poo poo the break in theory, so I guess it's all in my head (ears)

[billfitzmaurice]

Speakers do break in, but not that much, and certainly not so much that you can hear it. Your auditory memory window is far too short, and the effect far too subtle.

[Sydney]

Yes, It is real. Some suspensions take longer to loosen up. I purchased 4 woofers from a person who was dissatisfied with the sound. They broken in AFTER I ran them for a while longer.

[Billet]

I have been listening to my Old Skool coaxials every day in my listening room. They were built just in time for InDIYana and had only 5-10 hours of break in time before the meet. They seem to be getting smoother and more balanced sounding as time goes by. I can never decide whether the speakers are actually changing or my ears are adapting to the speakers.

I can switch to my previous mains very easily for comparison. Immediately after building the coaxials, my main speakers still sounded noticeably better. Now, they are pretty equal. Have the coaxes gotten better after thirty or forty hours of playing? Or have my ears gotten used to the new sound and now the old sound is less good in comparison?

The world may never know...