Shady, very nice review. Thanks for your good work and your reasonable approach to making sense out of modern methods of measuring speaker performance. Compared to the irrational comments on speaker vertical dispersion that I see on ASR speaker reviews, I much prefer your take on those measurements.
I'm old enough to have owned a pair of JBL L100a speakers since 1973. Some of you may be familiar with how I discarded their original inadequate crossovers, replacing them with crossovers designed by Dennis Murphy. In my opinion, that new crossover is still the best available for these old 3-way war horses.
… The Coast to Coast Sound Part 1 My first speakers were a pair JBL L-100As that I bought in 1973. I always enjoyed them and still use them today. Their easily identified sound, the so-called West Coast sound, was once a highly touted marketing feature. Ad copy claimed that musicians and...
forums.audioholics.com
So, I was interested to see JBL's modern approach to their re-design of an old war horse. Their new design uses three very different drivers than in the 1970s, and JBL does a much better crossover design. All make for a big improvement over the 1970s L100s.
The old L100 speakers had a few problems that even a new crossover could not affect. The JBL 123A 12" woofer was meant for a large sealed cabinet, between 3.9 and 5.9 ft³. (See below) The original L100 cabinet was ported and much smaller, about 1.8 ft³. It's bass performance had a Qts well above 1.0, and it sounded like it. There is an exaggerated peak in the range of 60-80 Hz. It helped sell a lot speakers, but it rang and muddied up the lower mid-range. So, I like the woofer that JBL uses in the L100 Classic. It seems to work much better in that cabinet.
View attachment 47242
The other problem in the original L100 is repeated in the L100 Classic. The asymmetric layout of three drivers was done in the 1970s, but just shouldn't be done now that we know better.
I've been told that JBL chose that strange layout deliberately, so owners could lie them on their sides or stand them vertically, without "significant" change in their sound. Most people I knew in the 1970s kept them on their sides. Shady's measurements addressed the affects the asymmetric driver layout has. It was nice to see that discussed with the perspective of your measuremets. Again, thanks.