Can speakers sound worse during break-in period?

To have a guy that is clueless and argues almost every point under gods creation is one thing,  but to have a guy chime in that calls himself a manufacture that apparently has never taken the time to measure drivers at several points of break in is beyond my comprehension.  FS, QMS, QTS and even LE and RE all change as the motor and suspension break in.  It is threads like this that makes me back off of posting. 

I am most fond of posters who argue one thing one day, and then within the same thread argue exactly the opposite. That kind of gymnastics will always be pretty amazing to watch.

Hello, 
Maybe we are coming at this in different directions. I still believe in what I said, but if I am understanding this is that the speakers should always sound good and get better. Just like my car analogy. If it sounds bad then something else is wrong. The only thing I can think is if you break in with a limited amount of frequencies you may run into some issues. If you play 1khz for a hundred hours then the woofer did not move due to the crossovers.  If break in on a speaker is not real then why do most manufacturers recommend this and tell the dealers to do this? Is there a representative from a speaker manufacturer that can weigh in on this? Maybe the OPs crossover is messed or he had some interference from other things. 

I suspect surrounds on midrange cones and woofers become more supple as they are used. Though that could vary widely depending on the surround material. Usually showing gains in lower frequency response and probably dynamics too. I was also told by a very prominent speaker designer that the caps in the crossover will "sweeten up" with several hundred hours of use. I guess he means the caps become more linear over time and thus differences could be audible and measurable. I would agree that if the speaker in question were to sound bad right out of the box, other problems might exist.

@mr_m 
a very prominent speaker designer that the caps in the crossover will "sweeten up" with several hundred hours of use. I guess he means the caps become more linear over time and thus differences could be audible ,  

This is very interesting , may be the caps is coming more dry or more juice