I recently purchased a used powervox brand 2800 watt car amplifier. Now have installed it to all the speakers and headunit ect but now I have tried to test it and it only comes through one speaker. fter this i swapped the wires around so that a different speaker was connected through the terminl marked "Channel 1". The sound then came out of this speaker only and no others. Any help on what the problem is or how it could be fixed would be great. I am only new to car audio so i really need help, Thanks!!