After juggling my options for way too long, I decided to just build a sub and see how it goes. Here's what I did: I bought a Dayton 12" DVC ($90 at ebay) and a 250W PE amp with no boost. I figured with a good driver and amp I can experiment with different setups. I built a 2.5 ft^3 sealed box. That was the largest box that would fit in my preferred sub location. The plan was to try it sealed, and if that didn't work, add a port. Using a RS SPL meter and the RS correction tables from the net, I measured the room response from 20 to 85 Hz. It is within 3 Db from 24Hz all the way up, except for a serious peak at 35-45 Hz and a smaller valley at 65-70 Hz. There is a significant drop from 24 to 20 Hz. Question: are those RS correction tables accurate? I hear a significant drop in loudness from 34 Hz down, but maybe it is my hearing? The adjusted RS values are pretty flat to 24 or 25. I should also mention that my peaks and valleys are nothing like the ones I expected based on the room simulation software I had experimented with. Is that normal? I understand that rooms are hard to model, but I expected at least some correlation... Anyways, now that the sub is working my question is: What next? - Add some boost at 20Hz? (4 Db looks about right.) - Add a port (tuned to 21.5 Hz)? Wouldn't that just add a bump to my reasonably flat in-room response? - Buy a BFD and equalize away (but that's a lot more $$$ than some resistors or a port tube) - Leave well enough alone? - Forget my current box and build a sonosub. I should add that this sub is primarily for movies, but I think accurate reproduction of music is important.