A novel cap for a telephone unit is provided to de-couple the loudspeaker diaphragm from the acoustic resonance in the enclosure and dampen the first resonant frequency of the diaphragm. The cap has a flange located at an outer edge thereof and a cavity provided in the cap. The cap cavity is sized to...http://www.google.com/patents/US20030063767?utm_source=gb-gplus-sharePatent US20030063767 - Device for reducing structural-acoustic coupling between the diaphragm vibration field and the enclosure acoustic modes
