If you have two 12" woofers, I would suggest you run each with its own amplifier rather than one amp with the speakers in parallel. My experience has been you can play louder and the bass sounds better. I suggest you buy a bridgeable stereo amp and a cossover that has both stereo and summed (mono) outputs--most do. That way you can experiment with both scenarios and decide for yourself. The subwoofer addition with an electronic crossover is the best upgrade to improve sound. Enjoy!
