switch your speake wires, right to left and left to right, and see if the problem moves. If it moves, the problem is not the speakers.
Also check your interconnects between the CDP and receiver. I was demoing a new CDP, and the one interconnect was not tight, so my one speaker cut in an out until I tightened the connectors.
Also check your interconnects between the CDP and receiver. I was demoing a new CDP, and the one interconnect was not tight, so my one speaker cut in an out until I tightened the connectors.