What about break in / burn in?

rjj45

Guys, I'm a member of a FB group "DIY Loudspeakers" that is admined by some senior people.
Recently, a discussion of break in / burn in for speakers came up, and the discussion was rancorous 
and shortly locked, but the opinion of at least one of the admins was that "Break in for speakers is a myth".

I've experienced driver break in over the first few hours.  The bass got stronger, and the midrange got clearer for mid/woofers.
Not so much for tweeters, IMO.
What about you?

Tom_S

I read most of that same thread and I agree with you. There is enough evidence documented on many forums that proves (using measured T/S parameters) many woofer suspensions do change after a good thrashing for a few minutes. I don't think I have ever seen any similar testing with tweeters. 

stephenk9

From what I gather, the parameters do change, but don't seem to make much if any difference in terms of designing for the particular drivers being used. The parameters seem to compensate for one another in a way that keeps the design constant.

rjj45

stephenk9 said:

From what I gather, the parameters do change, but don't seem to make much if any difference in terms of designing for the particular drivers being used. The parameters seem to compensate for one another in a way that keeps the design constant.

I agree, but the sound changes dramatically

Ed_Perkins

The question is does the sound change after break-in or do your ears just become more accustomed to the speaker over time.  The only way I know to truly make a determination is to perform a double blind test.  Take two speakers not broken in that can not be discerned statistically in a double blind test.  Then have one speaker go through  the chosen break-in procedure.  And then repeat the double blind test.  

Until then I belong in the Vance Dickason "camp" - five or ten minutes of break-in suffices.

jr@mac

My suspicion is that tweeters break in the same as woofers. You can hear it on progressive sine sweeps on a new tweeter. I have not taken any measurements yet, a winter project, but I have a pair of tweeters reserved for that purpose since they currently exhibit some noticeable differences between the measured unit and the virgin unit. 

Per the modeling doesn't change point on parameters changing - something has to give. Isn't driver sensitivity derived from the parameters? I have measured a lot of drivers in my life, and periodically come across a mismatched set that model similar (rarely an overlay) as far as F3 - but will generally exhibit a db or two of sensitivity mismatch, as well slightly different slopes on the roll-off. This can and does lead to tonality differences between drivers, not to mention confounding the imaging. So yes, driver break-in resulting in those same parameter shifts will lead to a change in sound. If one does not grab a new driver and beat the shit out of it at Xmax for several minutes, break-in very well could take many, many hours. I have no doubt this is exactly why there is such a thing as the concept of break-in taking forever, and why we sometimes assume it is our ears breaking in and not the speaker in question. I have no doubt that acclimation to change is part of the process, however. 

In the case of tweeters, I suspect Fs moves a bit with break-in, and since that resonance at Fs is a prime consideration of designing crossovers and I'm starting to believe the performance of a tweeter in the octave or so above Fc + how well any resonance at Fs is handled is the biggest contributor to overall tonality of said tweeter, I am not at all surprised that after a few weeks/months of listening the speaker tonality changes characteristics. 

TL;DR - break-in exists, it affects tonality, but the myth is that it has to take weeks or months. 

Wolf

I've had to manually massage a 2" dome once to get it to behave for measurements, so I don't see why a tweeter would be any different. I also know that Marty's Copper Project changed dramatically with the W5-1685 so he felt he had to redesign the cabinet. I don't know the outcome of that. AND- I've also broken in disparate driver pairs to try and get them to be more similar or behave. Sometimes of some benefit, sometimes not so much. I think it does depend on the soft parts utilized in the driver.

R-Carpenter

I simply stopped giving a shit about break in or possibility of it existing.

PWRRYD

But but but wait....  if high end caps need to break in (the more expensive the cap the longer the break in required) which have no moving parts, or at least their parts shouldn't be moving, then shouldn't drivers with flexy moving thingies need to break in?  Eh, never mind I need a beer

dcibel

To make it sound better turn the big knob clockwise.

Tom_S

dcibel said:

To make it sound better turn the big knob clockwise.

That's a line worth quoting!

dcibel

If you turn it far enough, you can break in your speakers and your caps at the same time!