I guess my question would be, what’s breaking in? I’ve heard that capacitors need break-in time, so the crossover might need some time. The drivers themselves are moving parts and it seems very likely that they might undergo a certain degree of mechanical change during the first hours of use, not unlike a new pair of shoes break-in. This probably is the primary effect actually, and seems very likely to be real.

I can only guess at how long it takes. Going back to the shoe break-in analogy, probably a month of regular listening will get you through the majority of breaking in. I personally don’t have good enough ears to hear it.

Wouldn’t it make sense that a woofer cone surround could be stiff initially, and become less so with some repeated flexing, like most any flexible material?

Or…are surrounds made of material that keeps the same elasticity it had when manufactured?