I think the issue with that driver isn’t that it can’t extend low, but that it exceeds xmax, very fast. Did you take a look at cone excursion via wattage? Or max wattage? I think you will be surprised that it hits max excursion really fast. Which really limits it’s low end output. I used this in the a few builds and I was disappointed with it’s low end output. I think these really are better suited for a 2.1 style build.