.....................at least it surely sounds a lot better.

Thanks to everyone that responded. I decided to go with Earl K's suggestion; the fix that would take the least effort, and for which I had all the items at hand; biamping. Also, Mr. Widget's rationale made sense that it is unlikely that a pristine set of L-300s like mine would have overdriven 077 and LE85 units needing diaphragms and magnet recharging.

My test configuration was to use an active dbx 223 2-way crossover crossed just slightly over 800 hz. I used a 125-watt s/s amp directly wired to the 136 woofs, and a tube 65-watt amp wired to the existing stock JBL crossover.

With a 24 db LR slope on the active network, and not knowing how quickly the JBL crossover rolls off the woofer, I thought it would be better to error on the side of both drivers covering a bit of this area, rather than having a frequency drop out from being too low. Any comments on this approach would be appreciated

QUESTION: The woofers were simply disconnected from the crossover and the leads taped. Does removing the LF load from the crossover change the crossover points on the MF and HF? Do I need to insert a resistor simulating a 136 load??

Anyway, the presence, clarity, and imaging have greatly improved. The increase in dynamics is staggering; clearly the biggest improvement, just as I was when I first biamped my Altec Valencias.

I think I can live with this setup for a long time. At least until next year.

Thanks for all the technical help. I'll attach some photos as soon as my kid’s digital camera.