problem with 5 channel amp

Hi everybody.I have a problem wiring my 5 channel VIPER 450.5 Amp into my 2007 toyota prius package #2. Here is a picture of my working setup (don't worry, it won't look like that when it's done.) You can see the relay, the video amplifier for the LCD's, the PAC OEM2 which is my line out converterI have the spliced into the wire running into the rear channel speakers because they are full range. I ran these into the PACOEM2 and then ran the output into the 1+2 input on the Amp.The amp is then wired to the rear speakers, the subs and it works perfectly. The rear and the Subs are bridged.When i wire the front speakers, the amp just puts out a high buzzing tone. I've tried to wire the front speakers into where the back are wired now and they work fine, but when I try the pack where I want to wire the front, I get the same high pitched buzz tone. I can't get them to work on where i want to wire them on the amp (it's actually labeled as the rear out on the amp, but I'm attempting to use it at the rear out. I can't think that this is the problem because when I try to wire the front speakers into the front and the rear into the rear, the problem is still there.)I have also tried adding and RCA input into the 3+4 input on the amp and the same problem happens. I have also tried switching RCA cables. I have also tried to have all the levels adjusted, the Phase 0 or 180, the sub input on/off, and the 3+4 input on/off.What am I doing wrong???

Just to clarify, the sound that's coming out isn't a background hiss or an engine noise, it's a buzz!! like the emergency broadcastings system, but constantly.

Could be a bad amplifier, bad LOC, bad speaker... if you swap the fron input to the rear channels, does the noise move with it?Support the12volt.com

There seems to be a problem only when the channel is bridged... when i don't bridge them, they're fine. I ve never run across this before.