Thanks Gr obi.
Yeah, the popping stops after a few minutes or so, but sometimes varies, which would lead me to believe it is something Apple could hopefully solve with a firmware update, but it is a problem nonetheless and unacceptable for the price of this computer.
I am going to call Apple Care this week and see what their suggestions are.
Seems to be a common problem with this model it looks like and the speakers are the achillies heal of this machine. The speakers aren't that great sounding to begin with and compounded with the popping sound, it makes me wonder why they attempted to make these iMac models so thin.