Sub making weird noise?

I plugged in my sub and it starts making this odd sound. When i started playing music and the sub hits it makes this awful sound. i dont know how to explain it. Its like a static, popping noise. I know its not the gain because even when its turned all the way down you can still hear the noisse. The box is the right size. and alll the connections seem to be alright. This has justt got me completely stummped. It cant be the sub becausee it is brand neww. Its an alpine type r 10d2. And the amp is a mrx-m100. Please help!