Bi-amping ADS L-1590 or L-1290

Abruceaudino, I have a pair of 1590's and had them biamped using an inexpensive rane crossover set at 350 hz.
Behind the low frequency connectors, move the switch to the left, for biamp operation. For what it's worth, I have a pair of pa1 amps. They do sound real good, but they are 25 year old technology and small. The speakers sound better with better amplification.

I have a spare pair of 1290s. I have bi-wired and bi-amped them without an external crossover. I used the internal bi-amp switch and I thought they sounded great. Maybe they could sound better with an external crossover but I never felt the need to try one. Even though I have the 1290s as a spare set, I will probably never get rid of these speakers. I would maybe trade them in for a nice pair of 1590s.

I may try bi-amping w/out the crossover just for the heck of it until I can pick up an external one. However, dont you risk damaging the speakers or at least ruining the sound by sending the full frequency to all the speakers? From what I gather, selecting the bi-amp switch in the back disables the internal crossover, which is why you need an external one to properly bi-amp them.