I just got a new pair of speakers. We'll need to me. Some JBL l56 speakers. I really like them. However when they were shown to me there was not very bassie music playing. When I got home I put some music on and I noticed that one of them pops a bit when the bass comes on. It also sounds like the speaker is underwater. When I say underwater I don't mean like it sounds muffled. I mean it sounds like if a mermaid swim up to me while I was scuba diving and started saying something to me in a gurgly humorous cartoon fashion. Bubble talk hehe. And then it does pop. What could this be? Speakers were made in 1981 . They sound pretty good till this point. I'm using a Rotel 970 BX integrated amplifier with 60 w per channel at 8 ohms