I found that the mylar on Martin Logan defintiely benefited by break in time. I am not sure about the xover.

Plasma TV's also benefit and in fact the latest with to run the new ones for 100 hours or so on an hdtv channel like Discovery to ensure that there will be no burn in on nomral viewing.

There is a rapid change in characteristics in both cases for the 1st 75-100 h0ours or more so that tweaking/calibratins can not be doen until after break in.

Joel

Joel