I put in an alpine stereo over 2 years ago and have not had any problems until this week. The drivers door speaker has no sound except for a buzzing. This has happened the last two times I drove xf, but after it warms up( if this makes sense). It starts working again. I never changed the amp hook ups. But I don't think this would make any difference except for more bass. I just don't know if I should look at replacing amp or speaker or what?!?!? I hate to just keep throwing parts at the problem. Anyone got suggestion? Please help! The buzzing has to stop!