1.7i’s have a major peak at 70 hz, which is why people have a hard time matching subs to them.
The important thing here is to stop the bass going to your amp, something as simple as Harrison F Mods can do that inline, which are inexpensive, just like a preamp would with a small filter, and so your amp will not waste any energy throwing watts into to your speakers that they cannot reproduce in the first place, plus a little extra by adjusting that up to 80-100 hz.
You will find that it is much easier to integrate the subs smoothly by knocking off the 70 hz spike.
Yes, the mid bass and midrange will improve when the deformation of the diaphragm of the panels is not reproducing as much bass, since the membrane is not traveling as far on the bass notes away from the magnets, which causes distortion in the upper frequencies by trying to reproduce those with fluctuating Tesla units.
What makes a ribbon and AMT drivers so accurate, the the surface of the sound source between magnets, a relatively constant magnetic field, makes panels so finicky, the surface in front of the magnets, creating a variable energy field.
Mathematically this is significant, as the energy increases and losses are squared with distance from the magnets.
