Newer speaker dating codes
The speakers remained heavily sought-after as replacements for amplifiers originally manufactured with Jensen speakers.
Following that demand, SICA Altoparlanti began reproducing "reissues" of the Jensen speakers in 1996.
Jensen Loudspeakers is a company that manufactures speakers in many different models and sizes.
The same magnet weights (and corresponding codes) were used on multiple speaker sizes, and the power rating increases with the increasing diameter.
Ceramic magnets are roughly 45% heavier than their Alnico equivalents that share the same code.
The current Fender Twin Reverb amp uses two 12" Jensen C-12K speakers.
The former Jensen Radio Manufacturing Company was founded in 1927 by Peter Laurits Jensen, the co-inventor of the first loudspeaker, in Chicago, Illinois.
The next one or two characters denotes speaker size (8 = 8", 10 = 10" diameter and so on).