A resonant disk that is used as part of a polar mount assembly. The diaphragm is tuned in flexure and is positioned at an antinode (one diaphragm at the transducer-booster joint and another at the booster-horn joint). Because it is tuned, the diaphragm prevents the escape of acoustic energy from the stack to the support structure (e.g., the welding stand).

Also see —
End cap
Clamp tube