Hi,
I agree with posters who have said that the particular comparison that you are making is a bit surprising. The SB16 is a sealed sub, intended for smaller rooms which benefit from more room gain, or for smaller spaces, where larger subs would not fit as well or pass WAF considerations. Some people consider sealed subs more musical than ported subs, but there is no real agreement on that issue. And, with 70/30 HT to music, I would not expect that to be a strong consideration, anyway. Ported subs can typically develop a lot more low frequency SPL, down to their tuning point, than sealed subs can. And, that is important for HT in a large room.
You have specified that the sub will be for a larger room, and the 118HT will definitely have more output than the SB16. So, given your situation, I don't think it is a very close call. The PB16 would be a better choice than the SB16, in my opinion, for what you have described, although it would also be more expensive. But, if you like the looks and features of the new SVS subs, those can be considerations. Purely on an output basis, though, the Cap 1400 would have even more SPL, at most frequencies, than the PB16. And, it would cost less.
So, in your situation, I would drop the SB16 from consideration, and concentrate on the 118HT, the Cap1400, and if you like SVS subs, the PB16.
Regards,
Mike