Abstract: An improved electromagnetic audible signal device has a coil and an associated magnetic core. A flexible striker arm carrying a movable magnetic contact is positioned above the core. A multiconvoluted diaphragm is located above the movable contact and the striker arm. The contact periodically impacts against this diaphragm generating an audible signal. The invention includes a spring and screw arrangement for linearly adjusting the gap between the core and striker arm. The same spring also serves to restore vibrational mechanical energy to the system which would normally be lost to the housing.