Very basic subwoofer question

I'm thinking of adding a sub to my two-channel system, which has a pair of KEF LS-50 speakers, on Sound Anchor stands. I'm generally quite happy with things as they are, except for occasionally feeling that I'd like a bit more on the bottom end. I'm not looking for chest-thumping, room-shaking bass, but instead want to hear what's not there now. Like Paul Chambers on "Kind of Blue," who sometimes feels more hinted at than present. Or Phil Lesh on "Friend of the Devil" -- or myriad other Dead tunes -- whose bass playing also isn't quite fully there.
What I want is to hear more rather than feeling it.
Is what I'm hoping for realistic? Attainable?
I could detail my system, etc., but I'm not looking for specific suggestions about which sub, how many subs, etc. I'm just hoping to hear from someone who might be able to tell me if what I want is possible, at all.
Thanks very much.
-- Howard