My friend has a bazooka sub in his civic. When the car is off and everything is all closed the sub still emites a low frequency noise but once you open the trunk the noise goes away. Im just trying to figure out whats wrong and how to fix it. I'm sorry for not being so specific but not really sure whats going on and how to describe it. If you need anymore information let me know and ill do my best to anwer any questions.

Ali

 

Im not thinking its the sub. Im thinking its the inside speakers or something around it. put somone in the trunk to listen to it.

 

or pull down your back seat if someone isnt willing to get in the trunk.