I found two Altec Lansing Model 9864A Duplex systems for sale nearby, and decided to pick them up. One was destroyed from being dropped, presumably from the ceiling it was mounted to, and the other was near perfect. I pulled the driver out of the broken one, it is in great working condition, but I've got no clue what it is. Attached at pictures. It is a 16" driver, with a 1.4" throat for the large horn pictured.
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Can anyone identify what the driver is? It measures 4.7 ohm DCR on the woofer and 5.5ohm DCR on the tweeter.