Sorry about the 1981 intro date and the time line. I got it all wrong. It just took a little help from you guys to get my memory working.

Altec converted all magnets from Alnico to ferrite (mid '70s?) when Alnico prices went through the roof. The converted 416-8C sales were very poor. For years contractors told marketing it was because of the ferrite magnet. In the late '80s we re-introduced the 416-8B with its Alnico motor. It never sold in the needed quantities and was again discontinued. This is when I believe the price was too high . . .

Here's what I think is the correct time line;

416-8A
Alnico
12,000 Gauss
3" voice-coil
30W
15 5/16" frame
date on data sheet 1972

416-8B
Alnico
11,000 Gauss
3" voice-coil
75W
16" frame
date on data sheet 1976

416-8C
11,000 Gauss
3" voice-coil
75W
16" frame
date on data sheet 1981

416-8B (again)
Alnico
11,000 Gauss
3" voice-coil
75W
16" frame
date on data sheet 1987