I have a pair of Maxwell NC-II headphones, aka ultimate metal concert hall in a box, with only the right speaker working many times. I would bend the chord near the plug a certain way to get both speakers working in stereo, so I decided to chop the plug and solder on a new shielded 3 conductor from Radio Shack. Did that, now only the right works again, but this time if I screw the shield onto the plug a certain distance, the speakers are in stereo, but if it moves a hair, once again only the right speaker works. So now I'm befudgled. Any opinions as to how to fix this?