Well, as it turns out, it wasn't the ZXM-RLC that was bad, it's something to do with my Kenwood head unit. When I run my iPod directly into the input RLC it works PERFECTLY. I must just be getting a poor signal from the head unit that is amplified by the line-driver portion of the RLC. It's weird that the sound quality is perfectly fine when I run from the head unit through the same RCAs to the amps, but whatever. I'm glad I figured it out, and THANK YOU to Kicker and Exile for such great customer service. I think I owe Kicker a few bucks for shipping!