[Vintage-Audio] JBL Century L-100 Crossover Change

[Duane Fischer, W8DBF]

Hi All,

I am told that the James B. Lansing Century L-100 speaker systems 
crossedover from the midrange to tweeter at 6000 Hz. However, the late 
production units had a crossover at 7000 Hz. The model was manufactured from 
1971-1977, I think. When did this change in crossover frequency take place 
and why?

How can one identify if he has the 6 KHz or 7 KHz crossover version?

Thanks!

Duane Fischer, W8DBF
dfischer at usol.com
HHI: Halligan's Hallicrafters International
http://www.w9wze.net
HHRP: Historic Halligan Radio Project
http://hhrp.w9wze.net