LE 14C Cone

I just discoved the LE 14C's that I purchased recently has a newer cone that the models the were produced in the 1960's The older model can be seen in the the catalog section of this website. The older model has a cone similar to the le15a-- a lot of stiffening ridges. The newer is a smooth cone covered with white '?plast.

So what is the difference in sound? Both appear to use the same crossover. Why did JBL make the change. Is the white cone superior for any reason to the older model?