Is it possible to determine the mfg date of a driver?
I just took possesion of a pair of 291-16A drivers
on the face is printed 391421 then a serial number 1866 and in a split box AL on top 53 on bottom.

Also, these measure 8 ohms, so I suspect the diaphragm has been replaced.
they look like gray aluminum. Are there any pictorial examples of different diaphragms?

As always thanks in advance

Kevin
Nov 12 2010