In the The Funk Brothers "Standing in the Shadows Of Motown" on DVD, Bob Babbitt playing a Fender P bass, appears to have a foam block or something similar under the strings near the bridge.

While this is obviously an attempt to dampen any overtones, I was wondering who else out there uses foam under their strings or any other alternative. Does roundwound or flatwound make a differnce in the choice of foam?

Any suggestions would be appreciated.

Gary