thats one way. we need to know more about the sub and amp though. you could just wire one voice coil, you could wired them in parallel if the amp is stable at 2 ohms bridged, or you can wire each chan to each voice coil. we need more info
New System in progress:
Phaze TD1500 ~> Dynaudio MD130
Phaze TD1500 ~> Seas g18rnx/p
Zapco Ref 500.1 ~ 12" tc-9
Behringer DCX2496 ~ Envision Electronics psu
On your sub there should be two positives and two negatives, wire the amp positive into one of the sub positives, then from the negative of that voice coil to the positive of the other voice coil. Then you wire the negative of that voice coil to the negative of the amp.
You then do the same to the other sub and wire it to the amp along with the first sub...
Once again I don't think you'll see a difference, but have fun