I need to respond to two of your statements:
"I am firmly in the camp that it was the speaker changing, and not my ears."
In my post I made the point that I believe you when you say you heard a change. I also went to great lengths to make it clear that I believe that what changes is your perception of the speaker's sound. Nowhere in my post did I take the stance that your "ears" change.
Then you said:
"In my mind, to know that this instantaneous change can, and does occur, and then to be unwilling to admit that the same process has been occurring from the first moment that the speakers were turned on -albeit at a much slower and less dramatic pace- just seems silly."
It seems to me that your saying anyone who doesn't agree with this theory is "silly." I do hope that was not your intent.
All that aside, if I understand your theory, you're contending that this process begins precipitously in the early part of a speaker's life, resulting in a noticeable change in the speaker's sound. But, though the process is ongoing, it slows to the the degree that no change in sound is noticeable. If this process indeed affects the sound of the speaker, no matter how slow the process, there should be additional change in the speakers sound whether it takes 1 year or two years, or twenty years. Either this process affects the sound of the speaker or it doesn't. It can't affect the sound at first, and then continue but NOT affect the sound of the speaker.
I had my AR5s 30 years. While I cannot say for certain that they sounded exactly as they did when I bought them, if they were different, the amount of change was so small as to be insignificant right up to the point when one of the woofers failed. If your theory is correct, after 30 years, surely they would have sounded significantly different as time went by, even sounding terrible as they neared the point of failure, no matter how slowly the process progresses.
More importantly, your theory is based on the premise that the "rubber surround, ...being stressed and pushed and pulled many, many times over the course of time" actually has an affect upon the way the speaker sounds. Do we know this for a fact, or is it only an assumption?
In any event, though I support you right to believe this theory, absent proof, I would hope that you make it clear to all that it is just that; a theory, and I would respectfully request you don't imply that anyone who doesn't see it your way is "silly."
To return to your point about how believers are treated, I think that can be explained by the frustration at seeing an unproven theory presented as fact (I'm NOT referring to your post), particularly when whatever evidence, or proof, is available supports the conclusion that speaker break-in doesn't occur.
