I am having an issues with my sub box making terrible rattling from inside. It is a sealed box by atrend for a ram 1500 crew cab. I have two alpine 10 type r subs. I had no issues till recently when I moved the sub box around to redo some of the wiring. After I finished the wiring I wanted to re tune it. When I started to do this I noticed a vibration coming from the middle of the box. I pulled both subs out to see if maybe one of them was damaged and tested both and found no issues. I have climbed from one side of the truck to the other and I can not figure it out. Any help is appreciated.