You should just get a length of 4-conductor wire and splice it in. Calls to Bose Tech Support no longer go to a person at headquarters in Massachusetts as they once did when my son was answering phones (along with about 349 of his former co-workers.) Now the phone rings in the Philippines.
Get some wire of same or larger gauge (size, smaller number is thicker wire),and splice. Many ways to do it, I prefer stripping the insulation back, slip a length of heat shrink tubing on, twist ends together, drop some good solder on and seal with the heat shrink tubing.