Anyone Bi-amping with tube high & solid state lows

Your post above specifies the need to controll gain dynamically. Can you clarify what that means? As I understand it, an amplifier has a fixed nominal gain. It is nominal because there is some reactivity to complex loads. So the gain may at a particular frequency may be a product of the impedance at that frequency. But the overall gain characteristic is fixed (unless of course there are level controls on the amp). Therefore, I don't get what "dynamic control" means. Is the idea that the active cross-over adjusts filtering in real time based on the level of the input signal? What is dynamic about the filter? I thought the only distinction for active cross-overs was that each speaker element is driven by one and only one amplifier, unlike passive bi-amping.

a..a!
who sais that gain of amp is fixed?? the word "impedance" already dictates that the gain of amplifier is not fixed.
crossover interfaces as a "third-party" component limiting visible freequencies of each amplifier.
with no active crossover even slight difference in gains at the particular freequency can cause a great deal of distortions and loss of a tonal balance; realy, the tolerance is too damn small to even match to same models(must be matched to each other good good good).
and yes the gain is controlled by impedance and and impedance is depended on freequency that is controlled by active crossover.

This approach gives the best of two worlds,the transistor amp will produce better low end response and the tube amps will produce sweet mids and high's My system is set up this way and my lows are crossed over at 250 hz down my tube amp are set at a 6db slope above works super.

I'm currently using a Parasound HCA1500A to power the bass and a Sonic Frontiers Power 2 to power the panels on my Innersound ISIS speakers. Sounds great, but I understand/ have been told that it would sound even better if I added an active crossover. I run a REL STRATA III subwoofer off of the Parasound.

Does anyone know if I need to get a 3 way crossover, or if I can use a two way and continue to run the REL off of the SS amp?

I am bi-amping my Wisdom Adrenaline 75 speakers using Rowland 8Ti/HC on the bass units and a pair of Red Rose Model 1 tube monoblocks on the ribbons.
This seems to work fine, but of course the Wisdom speakers include their active "Brain" electronic cross-over/equalizer which allows gain adjustment to the planars and woofers separately, so I can adjust the relative volume with ease. I can also adjust the "Q" of the woofer units.
Craig Zastera