You need to match RMS power for both the amp and the sub. I highly doubt, unless you spent a lot of $$$ that you have an amp capable of 1200 rms. Most cheaper amps advertise with ridiculous claims about their power ratings. Some of the cheaper amps will advertise 800W but really only put out ~120W rms.
I remember friends in school that bragged about blowing up subs with their 1200W Legacy amp. What actually happened is they underpowered the subwoofers and damaged them that way.