Subwoofer: How low should I go?

My B&W 683s are rated at 38Hz - 22kHz.

I've been toying with the idea of a small subwoofer to augment the low end a bit. My apartment is pretty tiny, and in a crowded NYC building so I don't have room for a big sub and don't need or want earth shaking bass, just a little more oomph.

The sub I've been looking at is the Velodyne Microvee. It fits the bill size wise. But it's rated at 38–120 Hz.

My question is, do those numbers mean the sub covers exactly the same low end as my speakers, making it useless? Do I need to go with a lower frequency sub to hear a difference?

They are not gettign the full benefit of using a subwoofer; it still might make for a system that sounds better to the listener, especially if the mains are truly lacking below 50-60Hz (small monitors).
It is all about the quality.
What you do not want is a boom box.
Get Rel. Good value and good performer.
Size is also NYC frendly. I should know - I live here.

Happy listening and
enjoy the music

i thought the rel, and some other subs, recommended running main speakers full range and simply running the sub high pass and using the on board sub xover to dial in the subs upper frequency cut off. for small, relatively well though out monitors, like my fostex 167e-based tektons, i want to get everything they reproduce and just augment, at the lower edge, since the main's aren't digging all that deep anyway, say 60hrz or so. anyway, that is what i do and am generally pleased, though my amp situation prevents me from comparing it to this other way of doing things.
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