Report "input is required from the sub woofer. Believe the popping sounds is coming from speaker. The popping sound comes on when the green light initially comes on. I'm not positive but I believe the popping is only when the bass is required not when the signal is not. I do know that the need for sub woofer ebbs throughout a song or movie. You can imagine how disruptive it can be. I have unplugged it to protect what ever is left of the speaker, and our ears. Thank You for any assistance!"