If you are looking for a sub that is non intrusive (small) but has the "guts" for movies, check out the MJ Acoustics Pro 50 MkII.
Links here: http://www.mjacoustics.co.uk/MJ_Acoustics/Product_html/PRO_50_MKII.htm

It's about $800 CA, so about $400 UK, $600 US..

I have heard this sub in person and for it's size, it's very impressive. Very tight, fast, controlled and loud enough for full on movies in small to medium rooms.


Acoustic Zen Adagio, Veritas center, Axiom EP500, QS8s, Anthem AVM20, MC20,Adcom GFA7400