Difficult to answer accurately but if there is a redish surround, it is likely an EV product. Beside, is there any whizzer cone ?
If yes, it is probably a SP12-B or -C.
If there is a black magnet cover with "cooling fins" around it and a silver grey basket, I would say it is a SP-12C which is an excellent speaker. I have the data sheet.
The SP12-B is a former model, with a 2-stage magnet cover of same colour of the basket.
To make sure, a digital picture would be welcome.

To be continued,
ERIC