Tight bass sub recommendations

As for Rel good subs but not necessarily a sonic match to every speaker and room.  

I highly recommend Monitor Audio Silver SW12 subwoofer.  For the simple reason the room correction microphone and 32 bit digital processor, which solves all of the room node problems and is the best implementation of a sub-woofer amplifier crossover I have ever experienced.  I use JM Labs Mini Utopia's, which are notoriously hard to match with a sub due to there speed and transparency.   This is a match made in heaven.   Other features include HYPEX 500 watt Class D amp and massive magnet structure on a Aluminum/Magnesium ceramic coated woofer.   Check this sub out before you buy anything else.

If the sub can't correct for the room then you will have plumpyier bass and it will not sound as if its coming from the main speakers.  Which should be the altimate goal.