It should work. The only reason it wouldnt is if as said before the sub is below 4 ohms. Most 4 channels ive seen only go to 4 ohms bridged. But yeah my friend has his car set up like that and it works fine. Id use front out to amp to components then sub out to amp bridge to sub then rear speaker outs of the deck to the rear speakers. Then jsut turn on the crossover for the sub and components. Is nothing working or not getting sound out of all the speakers?