Mike Coatham wrote:
"Chris Morriss" wrote in message
...
In message , Mike Coatham
writes
snip

1" voice coil, 13,000 Gauss field strength. Total Flux 54,000
Maxwells (In old pre-SI units)

I've probably got the Fs frequency somewhere.
--
Chris Morriss

That's interesting 'cos the 1971 HiFi Yearbook has them listed as
1" Voice Coil(Aluminium) , Gap Flux 14,500 Gauss. Total Flux 60,000
Maxwells. Paper cone with double diaphragm. H.C. 6 watts RMS 12W
Peak. FR 40-20,000Hz.



I got my data from an article by Gilbert Briggs. (Founder of
Wharfedale). They made them with both copper and aluminium voice
coils. The magnet might have been stronger in the later (1970s) ones.
--
Chris Morriss

Had another dig through my HiFi Yearbooks........the specs I quoted
earlier were in every issue from 1964( That's the earliest one I have
- they could be listed in earier issues, but I can't verify that)
until 1975........ 1976 onwards = oblivion ?

Do they still do hi-fi yearbooks?