You could series wire the sub and wire it to make the amp bridged.
Check the amp manual, or contact the mfg to see what the channel sepration as far as power and distortion are for your particular amp. If there is little to no separation I would say wire it per channel. Unless it's a 4 channel amp and your bridging a voice coil to the front channel and another to the rear, then what you are doing is an absolute no no.
But drop your amp mfg. a line and see what they say.
