Most whines and ground loops can be taken care of by simply grounding your empeg directly to your amps with nice, 10 guage cable. All 3 of my amps, my cd/radio, and my empeg share a common ground lead and everything is crystal clear. I know it's not always convenient, but hey, what's more important? Better sound, or a 1 time pain-in-the-ass install? The other key is to make sure the gain on your amps is set as low as you can. Make your player do the work volume-wise. Make sure you won't hurt your speakers when you turn everything all the way up. I have my empeg all the way up all the time. Yeah, I could turn the gains on my amps up to go louder, but who REALLY needs to?