Small Subwoofer?

[Redbeard]

I just put together an entry level audiophile H/T and music system comprising of an NAD T753 receiver and a full set of new Focal JM Labs Chorus S speakers. The system sounds incredible with amazing clarity and suprising bass down to 55hz from the 5" in the speakers. The problem is I would like to have more of a bass presence especially with the range down to around 25hz. The problem is that I live in a duplex and do not want to blow the neighbors sox off and get evicted. I am looking for a sub that will produce super tight, fast hitting bass to match the speakers. After listening to Tone Loc's Wild Thing I heard the speakers bottom out horribly on the bass notes and new I seriously lacked a subwoofer.

Don't get me wrong the speakers sound awesome with almost anything that is thrown at them and sometimes I dont even think they need a sub if you can believe that, to make a long story short I am looking for suggestions for a smaller sub that will provide tight, clean fast hitting bass without blowing the roof off. I looked into the matching focal sub but it only goes down to 40hz.

I have considered the Def Tech Pro sub 80, the Hsu Research STF 1, and several small M&K subs like the VX-7 series II. Someone also suggested the Canton AS22.

Anyhelp is greatly appreciated.