Wow, this has been a very educational thread!
So if I am understanding everything correctly, and please correct me if I am wrong,
1. I will get more oomph (SPL) with a ported sub, so getting a smaller ported sub could get me more HT performance than the sealed 12"
2. If I close my kitchen door while watching an action flick (romcoms are probably not a problem
), I won't be wasting energy on the other half of the first floor and will not need as powerful a sub to get the effect I want.
3. A larger driver will get to lower frequencies, so going with a smaller driver will have that tradeoff.
So comparing the recommended ported subs that fit my size requirements and I can actually buy here in the states (sorry XTZ, you looked promising!), all are 8".
Airmotiv S8: 33 Hz - 200 Hz, 200w, $299
Outlaw M8: 29 - 250hz, 125w, $329
Dynamo 400: 30 - 200hz, 75w, $449
Here are a couple more I spotted while ogling the first batch:
Aperion Audio Bravus II 8D: 32Hz - 350Hz, 300w, $399
Episode Element 8, 22 - 200hz, 260w, $250 on eBay.
The Dynamo is just not a good value in comparison. So between the other four, if the specs on the Episode Element are legit, that seems like a no brainer.
If someone snatches it out from under me, or the specs are BS, what do I want, more watts or lower range? I would think more range as 125W is probably plenty for my small room (with the door closed.)