Anyone with knowledge of subwoofers and amps

I was wondering if anyone knew anything about sound systems. I have a Dub audio subwoofer with a dual voice coil. I also have a Pioneer 2/1 channel amp. Would it be more efficent for me to run it bridge at 8 ohms or to run it one of the voice coil to the left side and the other to the right. The voice coils are 4 ohms each. My amp also runs at 4 ohms.

depends on wattage and rms as far as if its enough power (about 500 is plenty for a 12) but you should connect one positive to one negative (on the speaker) and then run the other positive to the positive on the amp and do the same with the negative making sure you bridged the amp with the correct positive and negative