On Thursday, August 28, 2014 4:37:20 AM UTC+10, Eiron wrote:
From the Wikipedia page on KEF:



"As Laurie Fincham, Cooke's successor as chief engineer, later revealed,

the only reason the B139 was vertically mounted ovoid-shaped was that

the British tax code at the time penalised products above a certain

arbitrary width."


So now we know!


** Also, having elected to make a molded Styrofoam cone woofer, the actual shape became fairly arbitrary.

In the 60s and early 70s, Yamaha made any number of odd shaped Styrofoam cone speakers to fit their electric console organs and guitar amplifiers. The cones were so large, their was hardly any room for a baffle or need for an enclosure.
Stiffness and hence resonant frequency were pretty high, but the huge moving area made up for that at low frequencies.

http://motosportz.smugmug.com/Electr...MG_7643-XL.jpg

The ones I came across had die cast alloy frames and ceramic magnet structures similar to the Kef B139. The foam thinned towards the edges so no flexible surround was required.



..... Phil