idc:Dan Turner:
I am firmly in the 'burn-in exists' camp - it's not just your ears. Many manufacturers cite this themselves, and I have never heard of a single one stating that burn-in does not exist. I would make sure that any component has had 50 hours of use on it before making any critical judgements.
Don't take our word for it, call up MF and ask what sort of burn-in period they expect before one of their products is on song.
Matrix Hifi, a Spanish site/ forum e-mailed a load of speaker makers and asked about burn in. The replies varied from no burn in, to a good few hours, to audiophiles tell us there is burn in! 76% report no burn in time.
Tests of woofers have found that they do change with use, but they will return to their original state if left unused. That return to the original state can take a few hours or even days. So burn in, as a physical change does happen with woofers and if a woofer is in continued use it will remain burned in. But if is not used it will return to its original state, so the burn in goes away. I have not found similar tests on any other type of speaker.
I have also not found any blind tests for before and after burn in on any hifi product.
Interesting, I have noticed a slight change in the sound presentation of my KEF speakers when returning from holiday but was not aware of this theory.