Does the popping noise happen on more than one source?
If not then that source is the problem.
Does the popping go away when you turn the volume lower?
If it does then you may be playing the TV louder than it can play. On most TVs you can't do that since the don't build in enough power so that would be so there may still be a problem.
If it doesn't then the problem may be the amplifier in the TV or the speakers. If the TV has a headphone jack try that.