I am using a 5ch soundstream amp and when I plug rca cables in for ch1/2 I get sound on 4 channels on the front and rear and I have not plugged rca for channel 3/4 yet. I am using all five channels 1/2 for the front, 2/4 for the rear and 5 for the sub. I am using 3 sets of stinger rca's. not cheap ones. But this would have to do with the amp.