[BC] Old Speaker

[Dale H. Cook]

At 06:34 PM 11/25/2005, Jeff Johnson wrote:

>cone loudspeaker. There was a thin rod protruding from the apex of the 
>cone which entered a magnetic assembly.

The driver was essentially a 1920s telephone earpiece - pretty much the 
same thing as found in a set of 1920s headphones. The cone speaker 
mechanically coupled the movement of the driver diaphragm to a paper cone 
to diffuse the sound, the horn speaker used the same sort of driver to 
excite a column of air in the horn. Neither had very good frequency 
response. The first speakers with decent frequency response were the early 
RCA electromagnetic speakers - the 100-A (1927), 103 (1928) and 100-B 
(1929), all of which sacrificed efficiency for better response by 
incorporating a passive filter network. When driven by a '71A output tube 
their sound was a great improvement over a cone or horn driven by an '01A.

Dale H. Cook, Chief Engineer, Centennial Broadcasting, Roanoke/Lynchburg, 
VA - WZZI / WZZU / WLNI / WLEQ
http://members.cox.net/dalehcook/starcity.shtml