wiring a dual voice coil sub

I have a two channel  300 watt amp (that is bridged) and 12" dual voice coil. I need to know should I wire it parallel or series and what happens when I wire it parallel or series?Eight valves of fury. Pushing it to the limits, Want more power.

It depends on what the amplifier is capable of driving safely. When an amplifier is bridged, the channels "see" one half the impedance (or twice the load) that is actually attached to the amplifier; i.e. a 4 ohm load is "seen" as a 2 ohm load PER CHANNEL. This being known, you then have to know what the voice coils are rated for, 2 ohms, 4 ohms, 8 ohms... whatever it is, you have to know it. If they are 4 ohms (the most common rating I have seen), and you wire them in series, you will end up with an 8 ohm load for the amplifier. Using the information from the FIRST paragraph, 8 ohms, bridged, presents 4 ohms to each channel of the amplifier.    Wired in parallel, you will have 2 ohms to present to the amplifier, resulting in a 1 ohm load, PER CHANNEL. Since you didn't tell any of us anything regarding your woofer (except that it is a dual voice coil) or your amplifier, (except that it is a 300 watt, 2 channel amplifier) with this information, now you should be able to figure out YOUR best scenario. I've done all the legwork for you, now it's time to start experimenting for yourself.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."