According to my experience the choice of a sub (or more than one) depends also very much on your room and its acoustics - and, of course, on the quality of the components in your stereo system (low, middle, consumer, high end).
I assume nobody out there knows or remembers the make of the sub I use: Acustik-Lab Stella Novus (originally spelled name), a Swiss made component which was very in demand in Asia in its time (and very costly, unfortunately). It allows settings in many ways, which was prior to today's DSP. (The company no longer exists.) So my favorite crossover setting is 42 Hz...quite discreet.
Set-up was quite easy, and I needed just some days to find the right listening setting (for me). As another A'goner wrote, the recordings (LP & CD) vary, and depending on that I am able to adjust the sub's settings (by remote control).