All about the bass

Since no one else has answered your thread and you are new here, I'll take a stab at it..
Tight, Powerful and Fast is really gonna cost ya. Like Wilson WHAMM or Duntech Sovereign.
Some suggestions on pretty good bass:
Vandersteen model 3 sig. or 2ce sig.
VMPS: some big ones with ribbons and 12" woofs
Snell: bigger older models esp. the Aiii had great bass
Sonus Faber: except for the really small ones.
Chario (impossible to find)
Nestorovic (also impossible to find)
PSB Stratus gold wasn't bad
AR (Acoustic Research) model 9, 3A, 11. All featuring the acoustic suspension 11" woofer. AR not really high end per say but great bass.
Bass depends alot on the Amplifier.. speed, clarity, current dumping/dampning factor all affect the bass in a big way. For example, I can hook up an old JBL L-166 to a pioneer receiver from the 70's, then hook up to my Eagle 4 and the bass will be COMPLETELY different (no boom just tight and powerful).

The speaker I heard with the tightest and fastest bass and within your price range is the Audio Physic Avanti III. I think it costs about $10k new but you should be able to find a used pair for under $5k since the revision V is out.

BTW, it does need a high power amp to come alive.

Better option, Def Tech Mythos ST's, <$4K/pair new.

Very efficient with bass down to 14 Hz via a powered sub in each tower. I had them in my rig and was pushing 110 dB peaks with bass to shake the room,

Generally a great sounding speaker to boot, you'd have to spend multiple times that amount to get similar response.

Lilu:

Very good topic and one where you should get a split in opinions. This is just my view: the benefit of using a sub woofer is that you can regulate your bass extension from one CD to the next by simply adjusting the settings on the back of the unit. This gives you I believe more flexibility than if you just had a large pair of speakers and just a bass control on your amp/receiver. It's simply amazing from one CD to the next how much I end up walking over to my sub woofer and adjusting it. For example, if I'm playing a CD by Four Play or Brian Culbertson (jazz), I have to turn the sub almost off. What size is your room and does it have thick carpet and much upholstered furniture? Is it on a first floor slab or wooden floor? In the $3K area, look at Rotel, NAD, Marantz, for integrateds. Is this to be a two channel system or home theater set up?