[miguel42]

what is the best way for tight accurate bass..a large driver with a short throw or a smaller driver with a longer throw..is one significantly better than the other or both equal ???

[JoshK]

This is asking to be contraversial, but I'd take a large driver any day.  Small driver + long throw = non-linearity.  We aren't even talking about doppler distortion and displacement advantages either. 

[JoshK]

The exceptions would be if you are using many small drivers, as in sub spread about the room, or if you are trying to make a sub horn reasonable sized, but that is a compromise.

[Scott F.]

Been down both paths, in fact own both. For my money I agree with Josh, a BIG driver is the way to go. Personally I use a pair 15"ers below 125hz in my main system. Rock solid and deep bass. The other issue is small drivers don't produce that room filling bass that a big 12,15 or 18 does. I've heard a few designs that come close but they still don't match a monster woofer.