New Plan

Background: I've been contemplating building a sealed high SQ sub for my two channel rig in two previous threads. I have a separate HT rig as well. My son and I just watched The Legend of Sinbad and I found myself turning my Adire Rava up farther and farther looking for serious bottom end reinforcement. I have heard the Rava in a friend's two channel rig and have decided to move that over to the two channel rig as it will be fine for what I want. Hence, I want to build a monster for the HT rig that will give me the deep low end impact I'm looking for.

Materials and Methods: I recently won an ebay auction for a PartsExpress 500W plate amp. I'm pretty sure that the Acoustic Elegance AV15 will do the job as the driver; from what I've read about it, it seems like a good "bang for the buck" driver that also sounds really good.

WinISD Results: In a vented enclosure tuned to 19 Hz, this driver will give me an F6 of ~16 Hz. The size of the recommended enclosure is a 26" cube with a 5" port of 13.5" in length.

Discussion: Is there anything inherently wrong with this design? Is there any reason to not consider this driver?

Please let me know if I'm overlooking something important.
 
I just checked for fun, you made that box linear. You should tune lower by using a longer port or use a smaller box to have a small rolloff in the frequency response curve. The room gain will bring the rolloff back to linear response. If you keep the box the way it is, you'll have climbing frequency response when going deeper in the bass.

You could use the same box with the same port, just make it around 21 inches long for a tuning around 16 Hz. (Assuming a box with 237 liters internal net when bracing, driver volume and amplifier volume is removed and if you use 3/4 inches thick wood for the enclosure walls.)

I think you could even make it smaller than that. I would need to simulate a bit more but I'm going on vacancy for a week, cya later hehe!