Subwoofer

Wolf_garcia, I agree, there is not much activity at 30Hz.   Another story is frequency response in the room.  My room amplifies about 30-35Hz extending response a bit, but extension is less important to me, than quality of the bass.  My speakers play all bass notes pretty much even, free of resonances.  Attack and decay of the string sounds very natural and undistorted.  Widely used overhang motor woofers often have huge distortions reaching 5%.  My speakers are also  (judging by the size of the magnets) overhang, but don't have bottom suspension (spiderweb).  This suspension adds to membrane's weight, slowing response, and affecting linearity of the motion.

Should you use the same speaker cable for subwoofer as main speakers?  Seems like the answer should be yes.  Or is there cable meant for subwoofers?

AFAIK, both WireWorld and Straightwire both sell subwoofer cables