I was just giving an example of its output in my room. Also the sub has a bass boost option that was turned up all the way, adds mid bass.
As far as servo subs making a difference? Absolutely makes zero difference in sound quality. Or at least to me. I’ve had Rythmik lv12r, e15, fv15hp, and fv18pc. None of these had better sound quality than other subs in their class. Just different output and extension. The best performance from a 15” ported subwoofer that I’ve owned was the monolith and not the fv15hp. Rythmik makes great subwoofer but at the new higher prices I don’t feel they are worth owning. Two years ago I bought two fv18pc in matte finish for $3200 and now it’s $3900.