[tommu]

My newly built Aircooled flat-4 needed running in. Lots of moving parts with fine tolerance needed bedding in. I quickly followed with an oil change to remove the anticipate swarf that resulted. Oil consumption reduced after 500 miles or so as the piston rings sealed up.

Then the vacuum diaphragm on my distributer needed to soften a little. On first use it wasn't flexible enough to move the advance arm quickly within the distributer so my spark advance curve was to low. After breaking it in it is much more responsive.

I would guess speaker diaphragm movement changes as materials wear, weaken or transform into their expected constituency.

Your toaster on the other hand.. maybe the oil will burn off the elements and your toast will taste nicer?