I have an odd ball pair of Jbl speakers that have an engraved B and 16ohm version of model LE15 plus it's got foam surrounds. Was told it's very rare and desireable. Normally the 15a supposed to have foam but 8 ohms. The le15b is supposed to be accordion surround and 16ohm. Im a bit confused what's supposed to be what. Can't find any info on the Le15b that's 16ohm with foam surrounds. Has anyone here ever listened to these in cabinet settings? This is not a 2216a or 2215. They are a combination of both maybe?