The SVS SB13 Ultra is a good consideration. I have two and they work well. Very fast, although they probably don't have as much output below 20 Hz (movies) as the PB13 (ported box), which is significantly larger. Plus, SVS has a 60 day free trial (with paid return shipping), and an unlimited 5 year warranty. Good deals off of their outlet page as well.
Golden ear sub x
I'm looking for an audiophile sub to go with Thiel 3.7?Looking to spend less than 1500.Local dealer told me about Golden ear sub x and raved about it?Isnt this mainly a ht sub?Also thinking about a Sumiko s9,I can get a deal on,maybe later add another?I do what a lot of movies but what 2 channel to sound good also!Dont need it super loud anymore,would be happy with quality over quantity.