Replacing Headphone Cables on Your Sennheiser Headphones
How To Install the Replacement Cable on Your Sennheiser HD650.
1. Make sure your headphones are unplugged from your source. It makes no difference whether you replace the right or left side first.
2. Remove the stock connectors on your headphones by grasping the connector and pulling straight out. You may need to gently wiggle the connector back and forth to loosen it; once it has loosened, pull down in a straight direction. Do not twist cord during removal!
3. The Cardas cable designates right by a red termination, black by the left termination. The little Cardas Nautilus symbol should face away from your ears when installing the cable. If your headphone cable is a stock Sennheiser cable, then it will be engraved with a small 'L' for left and 'R' for right on the cable connectors. Push the cable straight up into the earcup socket. You may have to push this in forcefully and you should feel the connector lock into place. Once the connector is in place, it will feel secure when gently grasping the connector and moving it around.