put it to 1000 watts at 2 ohm and dont turn the gain all the way up, lots of times people get a 600rms sub and a 600rms amp and turn the gain all the way up to get the sub loud, but there pushing the amp to its limits and then ur sending a signal that clipping. that creates more heat and in return u get a fried coil. this way when ur turnign ur gain up you wont have to go that high and less likely to be sending a clipping signal. true way to set ur gain is with a oscilloscope
plus the new type r's have been know to take up to 800rms easy. they put a 3 inch coil in them, if your model has a 3 in it its the new one.