I currently have a single Velodyne 12" sealed sub in a 20x40 foot space which is woefully insufficient. I plan to replace it with either a single or dual ported subs because of the large area.
I have a Dali Euphonia AS2 sealed sub with 2x12" wofers, and a B&W ASW 855 15" sealed sub, not using any of them, think if i was to ever use a subwoofer again i would build something with a lot of ported 6½ or 8" woofers, but i realy think ill let the front speakers handle it, and get a much better integrated low frequence without timing or other issues.
You do not give ceiling height, but even at 8', the volume of that room is large. You need multiple subs. If taking cost into account, I would go large ported subs.
My LCR's have 18's in them. I let them handle everything down to 40hz. Then the subs take it from there, down to single digits.
Like i like stereo, i like my movie sound to be as perfect as possible, and i never ever heard a subwoofer that integrated perfect with the rest, so i would rather use a set of Dali Megaline with 24x 6½" woofers, and have the speed/ start stop response of a small light unit than a big slow woofer, and when the front and sub track is comming from the front speakers its also most likely to be setup to integrate as good as possible with the room. I love low frequence, but hate subs..
I was like that too, until i got my DTS-10 subs. Most of the subs I had owned or heard in the past were too dark sounding or had the one note bass...now I have lows without the dark or one note bass.
Thats not the issue, its a bit more complex than that. At some point your front speakers and sub have to cross over, and its impossible to make that seemless.
i highly disagree with this.