On a side note, I also measured (SPL meter in same position) some tones through my sub (Aperion S8-APR), with the speakers disconnected.
With the sub's xover open:
45Hz - 80dB
50Hz - 88dB
70Hz - 90db
79Hz - 89dB
100Hz - 78dB
107.2Hz - 79dB
123Hz - 79dB
With sub's over set around 110-120Hz:
45Hz - 80dB
50Hz - 87dB
70Hz - 91db
79Hz - 90dB
100Hz - 72dB
107.2Hz - 70dB
123Hz - 70dB
So it would seem the low-pass sub out xover has the same slope of 12db/octave.
In any case, this little experiment showed me that my sub doesn't reach down to stated spec of 35Hz at -3dB in my room. This could be a factor of my room of course, but I would think the room gain would help the low end and not result in "peak" in the 70-80Hz range. I don't know enough about room gain and boundary reinforcement to say.
Maybe Craig should just release that CS-10.1 in a 12-12.5" cube like he talked about...

oke: The I will no longer need to care what the Aperion sub is capable of in my room.