Hello I have a problem with my sub and wondering if any of you could help me. I was driving to get me some Hardess this morning and noticed my sub was making a weird like whistling sound so I turned the bump off and got home started inspecting everything and both coils work like they should and it bumps just like it always has but when you push down on the speaker if feels like its rubbing. I tried blowing the coil area out with air to see if something had gotten down into it to no avail. So my sub is pounding the same with a kinda whistling sound and feels as if something is rubbing together. Any suggestion? Thanks guys!