Wow...I sound tired in this one. Bronchitis/mild pneumonia is no fun, but my abs are getting a killer workout from the coughing fits...lol.
Since I'm explaining and rambling off the cuff and just record it and run it...like I always do...I'll explain some L100/4311 crossover stuff here.
The first gen L100 Century and 4310 had 12dB/octave high pass filters only... a capacitor in series and an inductor in parallel... on the midrange(1500Hz) and tweeter(6000Hz) No low pass filter on the midrange. Later L100A and 4311 simply had a series capacitor on both midrange and tweeter at about the same frequencies. This is a 6dB/octave hi pass only. So...both mid and tweeter overlap on the highest frequencies.
The burning question is...WHY?
The answer is the Jim Lansing designed, Altec-Lansing 604 Duplex Studio Monitor of the 1940s, also known as the Iconic. In the 1960s JBL's Bart Locanthi was tasked with designing a more compact studio monitor to compete with the very popular Altec 604. The 604 has a very midrange forward frequency response. Mr Locanthi's team came up with the JBL 4310 Studio Monitor that very closely matched the frequency response characteristics of the Altec 604 in a package about 1/2 the size. The 4310 was so popular with recording studio engineers that they would take them home to enjoy. Thus...the consumer version L100 Century was devised through some marketing genius to promote recording studio quality sound at home. Genius it was, indeed. The L100 had become the best selling loudspeaker system in the history of JBL...as well as the most durable. So many of these models are seeing repair service for the first time in 50 years. More records were mixed on versions of the 4310/4311 in the 1960s and 1970s than any other monitor of the era. Most radio stations used them as control room monitors as well. I was fortunate to have restored some 4311s for KFI AM640 radio back in the 1990s. The station engineers were thrilled to have them back in glorious service.
So many audiophile snobs will criticize the midrange forward character of the L100/4310/4311 model...while they might be listening to recordings that were mixed on them.
Long live the L100 Century/4310/4311. It's an icon of US Audio History.
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