so i just finished wiring a single alpine type r 12 inch sub in my blazer. Im running the full 500 rms to it from an alpine m1000 amp at 4 ohms. what ive noticed is that at moderate to high volumes, especially with the rear hatch open, the sub "pops" as it hits. im not sure what it could be doing this, i made the box exactly 0.7 cu ft as specified by alpine and its completely airtight ? anyone have any ideas?

 

bad ground, possibly cooked VC, if its a flapping type pop then something around the basket could be loose, hole in the surround etc

 

possible you set the gain wrong

 

all i can think of is that the cone isnt sealed properly so im gunna grab some fresh weatherstripping this weekend and see if that helps