I have the same Paradigm sub along with a Seaton Sound Submersive with the AV8801. I have had the two subs for some time. Previous to the AV8801 I had been using a Velodyne SMS-1 on the Paradigm which helped and did some adjustments from XTZ measuring with Submersive, but results are far, far superior with the Audyssey XT32 on the AV8801. I am very pleased with the two subs integration. I could somewhat localize the Submersive previously, but due to room and furniture conditions, was limited in location. I no longer can detect subwoofer locations and speaker presentation is very balanced. At first the bass seemed "less" but really it has subtracted the boom and overhang. You can play with Bass in tone and individual subwoofer settings after calibration, but I have found I prefer to leave as calibrated.
Take your time in mic positioning when calibrating--I used an old Manon 800 camera tripod which has been very helpful for me. Lastly, suggest you switch the Paradigm to Always On instead of Auto On. I find it important not only for Audyssey calibration but also in music listening in multichannel. It may be somewhat influenced by my crossover settings, but for music (not 5.1 or LFE encoded) I often found the Paradigm sub did not trigger on. My mains are set full range--Audyssey set them as Large as well as Sides and Wides. Sides and Wides are also Paradigms--Active 40's, and I manually set them to Small at 60 Hz crossover. The mains I left as Large, manufacturer specs are +/- 2.5 db at 20 Hz. My center and rears are Small along with Heights, which are set by Audyssey at 200 Hz. I would have thought these higher roll-off crossovers would trigger on the Paradigm, but not always. Possibly the routed signals are higher frequency or not sufficient intensity. In any case, I now leave this sub Always On.