basic question: advantage to DVC sub?

if you didnt totally understand.......

DVC allows for more flexibility in wiring......no difference in SQ or anything it just helps when you have more than 1 sub.......

you can check rockfordfosgates website in RF tech.......it'll show you the difference between ohm loads with single voice coils and dual voice coils........................

if you dont know anything about ohms........ the lower the ohm the more power the amp produces......but most amps are 2ohm stable......and run more power at 2ohms on both channels than 4 ohms on both channels...........and max power is usualy 4ohms mono(1 channel bridged)
say you have an amp that produces

100 watts x2 @4ohms RMS power
it might produce 200 wattsx2 @2ohms rms power
and 600 wattsx1@ 4ohms mono

just an example