Wow, a review of a component I have used for decades, and it actually has decent performance! Thanks
@amirm! This has been my "go-to" analog crossover for many, many years.
The crossover circuit is a standard Linkwitz-Riley (L-R), don't remember what opamps are inside or anything else about the circuit. The L-R topology is a cascade of two second-order Butterworth stages to provide phase and amplitude matching at the crossover frequency with 24 dB/octave (fourth-order) roll offs.
For many years "pro" subwoofers were crossed at 40 Hz, not sure if that is more than an industry standard, but it has been that way for decades (at least IME).