Mercedes Forum - Mercedes Benz Enthusiast Forums - C230 Right Rear Speakers Low/Intermittent

I've searched around but have not found what seems to be my problem.

I have a 2000 C230K Sport with a factory radio/CD changer/deck, no phone installed. I've never had any problems, I bought it new. Recently, I noticed the right rear door and back deck speakers seemed to be out. But when I faded to the rear and balanced to the right and cranked the volume, one could detect sound emitting - crackling a bit and a little inconsistent, but definitely sound. It happened with the CD, radio and tape player.

I did what any red blooded American would do - with the power off, I tried thumping it to see if sound would change. I also ejected the CD changer. When I resumed power, things were fine! But during the course of my day driving, at some point the sound went out again. Same as before, very low volume emitting from the right rear door/deck speakers.

I've noticed now sometimes the CD changer thinks no CD is in a certain slot (I see "NO CD1" for example, when there is a CD there). I don't know if these are interconnected. But I did read the Benz manual, and it says that there is some connection between the different components, and failure in one of them can lead to failure in others (they cited the CD, phone and radio). It said, "Call your dealer".

Sometimes before work I pop the CD changer out, tap on the bottom of the rear deck speakers from my trunk (where the CD changer's located) and it works for a bit. But it always goes out again, usually within my commute to work.

I'd like to know if anyone out there has an idea of what's going on. If it's an amp, would it be intermittent like this? And is this something I should go to the dealer for? I admit to not being very knowledgeable about car stereos, so any help/advice would be greatly appreciated. I just want to hear sound from all speakers!

(More information: today it started working, and I faded to the rear and balanced solely to the right. The sound was fine at first, then it started to lose volume over a minute until it was basically at the usual very low point. What gives?)