Speakers stopped working

This morning when I turned my car on, my speakers all of a sudden stopped working....When I turn my car on or just the stereo, I'll hear a single pop coming from one of the speakers on the passenger side. None of the other speakers will work, but I'll still hear the lows coming from my sub. As of last night, my speakers where working fine. When I moved my car from outside into the garage late at night, my speakers were still working fine. Then once I turned my car on this morning, they stopped working. This has happened once before where I heard a popping noise from the speaker on the passengers side, and then none of the other speakers except for the sub would work. But once I turned my car off and then back on, the speakers continued to work fine until now. Any idea what is up? If it was a blown speaker, then why would all of the others shut off as well?

Some more info:

I have a 2000 Subaru Impreza Outback....The Head Unit is a JVC KD-R610 that powers all 4 speakers and 2 tweeters. Then I have a 300W Polk Audio amp that powers a 10" Kicker sub