[Wayne A. Pflughaupt]

A test mic is not nearly a sensitive as your ears are. Breaking in the speakers, if it does anything audibly beneficial at all, isn’t going to be “seen” by the mic – i.e., increased detail, improved dynamics, etc.

By the way, I recall reading in one of the late great hi-fi publications that a good way to break in speakers is to play pink noise at a low level overnight or while you’re gone to work. Pink noise is more steady-state than program signals, as it produces all frequencies at a uniform level.

Regards,
Wayne