Difference between L300 and L300 Summit

Is there a difference between JBl L300 and JBL 300 Summit?
Thanks

I believe the difference is simply dates of production with the older (Summit) perhaps having AlNiCo magnets and the later (L300A) having ferrite, though the magnet cut-off dates may not coincide with the "Summit" labeling on the foilcal. They seem to say either "Summit" or "L300" but not both and not "L300A".

http://www.jbl.com/resources/Brands/... summit ts.pdf