Your speakers are probably "out of phase." This occurs when a speaker cabinet is miswired, resulting in one or more of the speakers traveling in a different direction than intended, often causing signal cancellation in the lower frequencies. For instance, a 2x10 speaker cabinet that is out of phase would have one speaker cone traveling outward and one travelling inward, resulting in little or no sound. Use a 9-volt battery and the following procedure to determine whether or not your speakers are wired out of phase:
|Turn off your amplifier and unplug the speaker cable from the amp, leaving the other end connected to the cabinet.
|Touch the positive (+) side of the battery to the tip of the phone plug and the negative (-) side of the battery to the sleeve of the phone plug. When you do this, the cone(s) in the cabinet should all move in one direction—outward. If one (or more) of the speaker cones moves in the opposite direction (inward), then it's out of phase.
|Remove the out-of-phase driver (or drivers) from the cabinet and check the speaker leads to determine if the positive leads are all going to the positive posts and the negative leads are all going to the negative posts. Chances are that they are not. Correct the positioning of the wires (i.e., positive lead to positive post, negative lead to negative post), secure the driver to the baffle, and you should be back in business.