I have two subs right now, an SVS PB10 and an Hsu VTF2.4. I have them calibrated but I am not sure if I am getting any benefit out of the SVS as it's a 10" woofer. Thoughts?
Only you can honestly answer that question. What I would do is take the second one out and watch some movies and run through some tunes. If you don't feel you need it, keep it out of the system and sell it. Otherwise put it back and enjoy.
Taking measurements of both scenarios would help as well.