My system sounded great up until I had to do some work on my head unit. Now my sub makes a slight farting noise that's only noticiable if you open the truck and listen to it. From insidethe car it sounds fine and is still as loud as ever but Im affraid of hurting the sub. I tried going back to the head unit and reconnecting everything again but that didnt do anything. I know there's no problem with the gain cause I can turn the gain all the way down and still here the noise. Ive played with the amp but it continues to happen even at low volume. It kinda sounds like the sub is hitting something inside the sub.(i allso looked into that but thats not the case either). So if anyone who might know something about this i could definitely use suggestions.

 

Does it sound like something is viberating inside or does it sound like its constantly making noise?