Biamp question

I'm doing exactly what you trying to do. I use a Parasound 21 for the woofers and a tube amp (set 300B's) for the tweeter and midrange. I looked at your preamp outputs. I run my Parasound with XLR outputs from streamer/Dac directly to the Parasound and  RCA outputs from streamer to my set amp. My streamer /Dac does not have an output selector so both outputs work at the same time. You will have to figure out if outputs from your preamp can be run simultaneously. Otherwise you will need a splitter. The gain from the XLR out will be twice what the RCA output is, so if your stuck using a splitter use XLR. Also, you are correct as the gain control on the Parasound can be used to set the woofer volume to match the tube amp output. I use a program called REW and microphone to adjust the output/volume levels on the Parasound to match the tube amp volume. But that's another "rabbit hole" No messing with the crossovers-Parasound to woofers and tubes to tweeter/midrange speaker posts. Sounds sweet. 

@backdoor 

"Thank you all! I believe I can manage the active crossover (possibly) but my chief concern is disabling the crossover in my speakers."

As it should be.  The crossovers do much more than dividing the frequencies.  They also may include-

1) Baffle step compensation (reduces front baffle reflected midrange and treble so as to even those frequencies with the bass, can be as much as 6db. 

2) Impedance flattening circuit.  Makes the woofers easier to drive and have a flatter response curve.

3) Notch / peak suppression filter.  Reduces the magnitude of driver break up frequencies or other frequency peaks that a typical crossover and slope cannot deal with. 

avanti1960 - I don't agree with the benefits you've listed, not even one. Nothing is going to give you a flatter impedance or response curve than eliminating those capacitors and inductors. Together with variable crossover points and or a DSP, you will accomplish everything you have mentioned much better and greatly reduce intermodulation distortion. I know you won't agree, but that's what this forum is about, sharing opinions and knowledge. Happy listening, no disrespect intended.

The Legacy SE crosses from the woofers to the 7" mid at 180 Hz. 

Bi-amping without a crossover loses all the benefits of bi-amping. I.e. the additional 6dB additional headroom .

Baffle step compensation, impedance leveling, and frequency equalization are all lossy, passive functions attempting to fix basic design flaws already dealt with in the overall speaker design.

Biamp, but do it right - ask Legacy for their recommendation.

@backdoor 

agreed, bypassing crossovers can work and work well but DSP per channel with parametric EQ and knowing the driver's parameter are musts.  

DSP is also a rather large rabbit hole.  took me two years to fine tune my car's active 3-way plus sub system.