Are you going to DSP in a sub and “super tweeter” of sorts?
My main speakers (which have been meticulously restored with modern crossover components of the same spec as original, just modern materials),were tested by Julian Hirsch, Hirsch -Houck Laboratories (of Stereo Review Magazine fame) to be:
'At the system resonance of 60 Hz, the output was only about 2 dB above its average level in the upper part of the woofer's range, and even that minor output variation was spread over almost two octaves. When the bass curve was spliced to the room-response measurement, the resulting composite frequency response was flat within about ± 2 dB from 26 to 20,000 Hz.'
With my NAD 2200 triplets (one of which is the unit Amirm tested) in a bridged mono at 4 ohms left & right amps (speaker load is a low of 4.6 ohms) and the third amp running stereo into the subs at the L & R subs 2 ohm load, the only DSP that I SHOULD need (I'm being very hopeful here) is from 80 Hz to 15 Hz.