Abstract: A damping device which is disposed between an oscillating mass and a fixed structure. The device includes a rigid container, a first membrane forming the lid of the container, a low-viscosity liquid inside the container, an elastomeric diaphragm separating the space inside the container into two chambers, a second elastomeric membrane forming the base of the second chamber, and annular conduit with its two ends hydraulically connecting the first chamber to the second chamber for damping low frequency and high amplitude oscillations of the oscillating mass. The elastomeric diaphragm extends up to the annular damping conduit, and the diaphragm forms at least a portion of the conduit wall.