I turned my bass amp on and had all my stuff hooked up and started to play. Then I noticed my cabinet didn't sound as good as usual. First I just thought it was vibrations from being close to the wall so I got down closer to each individual speaker. I noticed one was rattling pretty noticeably. I tried tightening down the screws holding it in. After this failed, I proceeded to remove the speaker and check the wiring. It was a little loose so I took it out and put it back in. I made sure the wires were fairly tight. When all was said and done, I started playing again and it sounded great again. After about 5-10 minutes the rattling comes back. WHY?! I sat in front of the cabinet and made sure it was the same speaker. While I was holding notes I lightly touched the speaker and the rattling stopped. What do I do now?