at the subwoofer High-cut i set to 70hz and volume knob at about 10:30 o'clock position.

if can don't get 12 inch sub for these A100 speakers might have a sound hole or over powered it because A100 i tested in my room (my room is small about 6 x 8 meters) and i do a bass frequency sweep test, about 80hz start and below the A100 bass starts to drop already, listening by ears, but it also depends on your listening position because my position is middle of room, if ur listening position is at the end of the wall then it is very audible bass even around 70hz it will be shallow but audible....

i simply use this youtube sample for bass sweep test
https://www.youtube.com/watch?v=LJ6Hc3zH5KE

even though the specs written is 52hz - 40khz but in real scenario for my case my room listening it starts about 75hz and bove is more audible (can feel the sound), and my subwoofer starts to kick in louder around 83hz and below, by my ears listening close...... i believe my room is consider very small already if your room is bigger A100 gonna be more loud audible maybe around 80hz and above (mileage might be vary depends on your listening position and subwoofer placement).

i set all the volume is very balance almost can't feel the subwoofer is there when listening music but can feels the vibrations overall from my seats, it feels like the bass is coming out from the both channel of the A100, i prefer like this, if volume up the sub abit higher can feel too much bass coming from that subwoofer direction covering the A100 speakers.

ignore my messy room stuffs