That type of cast frame is the form that Goodmans (when they were still
a respected speaker company!) used for the later versions (around 1970)
of the Audiom 51/61 range and the Axiom 201/301. (If they are 12" that
is, the 15" unit was the Audiom 81)

These were the hi-fi versions with a plastic roll surround. Yours sound
like the PA versions with a plasticised corrugated paper cone
termination. Is this the case?
--
Chris Morris

Yep, no plastic roll here. I remember seeing a couple of those back in the
eighties, they were some
double cone type.. the plastic was all wrinkled even they weren't that old
at the time.
So my speakers are of Audiom range, right?

Thanks

Simon