Yes Dr. Barton took some of his reference speakers and then measured them again over a decade later and they were within .5dB of the original measurement. In other words, no change.
Sometimes if you measure speakers a few times, you do get a variation of .5dB
it's brain break in, not speaker break in.
here's a simple way to prove it to yourself. buy two pairs of new speakers, different models. Listen to them at different times, and you'll see that every time you switch it takes you a bit of time to get used it. No, the speaker is not 'un-breaking in'. Your brain is just not used to the sound of it.
Eventually, though, you will get used to the sound of both.
Same goes for wearing wool socks, starting a new job, eating a different kind of food, moving to a new city, etc... the wool doesn't get soft, the food doesn't taste better, the city doesn't become simpler, it simply does those things RELATIVE to you.
