Need info on JBL C51 Apollo speakers

Yes, buy them if you can. They could have any number of
different JBL systems in them---from a single D-123 to
the top of the line S-8 System: consisting of the LE15A,
and the 375 horn driver with lenses and crossover. Best
way to tell is to take the back off, look at the speakers
for model numbers and name. If nothing else, the cabinet
alone is worth buying....Carl

If you don't want them I sure do. They would go so well with my Delphi equipment cabinet. I'm in Michigan

You can look up audioheritage.com for the specs. I bought a pair in very good condition for the equivalent of US$ 2,800 (not a typo) from a used hi-fi dealer in Shanghai. The set is of 1964 vintage but the sound is first class because of the alnico magnets used in the LE14A and tweeter/midrange drivers. These are high sensitivity drivers that are very expensive to manufacture. These are regarded as way better than the JBL's manufactured after 1973 using the cheaper ferrite magnets. You will note that in recent years JBL has gone back to alnico drivers for their top end K2 series. The Apollos are rare and are just below in ranking to the Paragon, C50 Olympus and Hartsfield, which are considered the best vintage speakers in the world. Make sure the drivers sound fine. If you look up a website called something like vintage electronics, you will find many people selling the drivers alone for good prices. Have fun.

Gary