In the picture below the waves are exactly 180 degrees out of phase so that the peak of one wave lies in the trough of a second wave. If the wires to one speaker are accidentally twisted the sounds fr...In the picture below the waves are exactly 180 degrees out of phase so that the peak of one wave lies in the trough of a second wave. If the wires to one speaker are accidentally twisted the sounds from the speakers will be out of phase and tend to sound softer (the destructive interference isn't complete because of echoes and different distances to the listener). Notice that the waves start from the far end of the tank, reflect off the near end and eventually make a set of standing waves.
