What? Space Balls? What are Space Balls?
Space Balls are used by cabinet makers to "float"raised panels in cabinet doors. Guess what? They work great to inhibit undesirable vibrations from the strings on the right side of the hammered dulcimer's bass bridge. I heard it from Ruth Smith. She heard it from Chris Foss of Songbird Dulcimers. I put it to use this weekend. It works!
Check This Out ... Little rubber balls. Cut a shallow slit on opposite sides of the ball. Insert between the strings on problematic courses. The string will pop into the slit. Slide from side to side until desired effect is achieved.