I have a pair of L100s and a pair of 4312Bs that I love.

I've been reading a lot about these designs. Many people think that they benefit from an upgraded crossover, but I've been hesitant. I love the way they sound already, 6k spike and all.

Proponents of a crossover upgrade note that there's very little to restrict all 3 speakers from playing everything. With modern crossovers one needn't do this, leading to designs that deliver flatter performance.

In discussing upgrading crossovers it is noted that JBL wired these speakers so the midrange driver is out of phase. That struck me as odd.

But suddenly it makes sense.

Is it possible that JBL engineers were using phase cancellation as a form of crossover? That is, where the woofer and midrange overlap, the phase cancellation leads to a form of attenuation of the shared frequencies, thus staying "flatter" (seeming) than they would reinforcing each other? And the same for the frequencies shared between the mid and the tweeter?

Further, could the odd "spatial" effect of speakers running out-of-phase... in this case, not from side to side but equally inside each cabinet, create the "magic" of the L100 sound? It's obviously not physically hi-fidelity... yet it's just the sort or ear candy that could be perceived as pleasing with greater perception of depth. Could the 6k hump caused by the asymmetrical placement of the midrange driver in the baffle also be intentional; to create the perception of definition and "pull the ear away" from the phasey mids below 6k?

It's just a hypothesis; thoughts? Could this be so? Or have I misunderstood something?