In my experience, break-in time depends a lot on the types of capacitors that are used in the crossovers. The drivers themselves generally loosen up in 20 hours or so, but the capacitors can take much longer. Many film caps, such as some of the large copper foil in oil caps, can take hundreds of hours, and I've heard (never tried them) that Teflon dialectic caps can take up to 1000 hours.
Break In Failed
There is a new set of speakers on the way and after looking for tips on speaker break in, the topic hits left me smirking.
Good advice like face the speakers and wire one out of phase, use heavy blankets and leave on 24-7 for weeks.
The amusing part was exercising them at ~90dB for excursion during away hours. My current speakers have seen that level in my apartment for maybe an hour in the years since owning them. Did I fail at break in protocol?
I anticipate feedback recommendations of connect and enjoy the music after leaving them on for a couple of weeks at my normal listening levels, which has served me well in the past.