Originally Posted by Full_Tilt_Boogie
Speaking of retarded **** audiophiles think...
The above just connects the woofer section and tweeter section together so that the user can use a single (pair) wire to connect to the amp.
Manufacturers allow you to wire them to separate amps - "bi-amping" it's called, which has advantages even if the crossovers are in the speakers rather than using "active crossovers" which sit before the amps in the signal chain. (common in car audio)
Bi-amping has the potential to reduce intermodulation distortion especially when the bass channel clips. The distortion products are high frequency and if the tweeter is on a separate amp it doesn't reproduce them.
Even without clipping, when playing loud and the woofer reaches close to its excursion limits its impedance goes non-linear (impedance changes). This interacts with the amp+wire's output impedance (ironically, worse with vaunted tube amps), again creating higher frequency harmonic distortion products (more in the midrange in this case, less in the high frequencies, as compared to clipping). If the midrange and/or tweeter is on a separate channel, it won't be there to reproduce them.
Bi-wiring (to a single amp), can measurably do the same thing, if wires are long and skinny, and to a smaller extent. Thick wire and most modern solid-state amps will negate the effect.