Of course, it could be a defect, but there might be other things also. Have you swapped speakers to see if there is a difference? Not the cables but the speakers? I had a situation in an apartment where my right speaker was closer to a corner of the room and that completely sucked the volume out of the speaker. I tried swapping the cables to no effect and was going to send them back. Someone suggested I swap the speakers and they both exhibited the same behavior on the right. I moved my mixing desk away from the corner as far as I could, and another foot or so from the wall and that helped a lot. Good luck with solving your problem.