Help me ID this driver

I just picked up a pair of pro audio subs from my local pawn emporium at what I think is a very good price. They're Sound Bridge S3 s118sw. They're trapezoidal, sealed birch ply with one 18" driver, nicely braced and with good internal stuffing. The drivers have the Electrovoice EV on the duscap, as well as the squatty, massive magnet structure typical of EV. There aren't any other markings on the back I can see except the manufacturer date code. Any thoughts on which these are and where I can get some specs?