Reverse alarm

An electronic alarm comprising, a housing, mounting means formed on said housing, said housing including a dish shaped cavity defined by a sidewall and an inner projector wall intersecting said sidewall, said cavity including an opening intersecting an exterior surface of said housing, said projector wall facing said opening, a diaphragm mount assembly located within said cavity having an axis and an inner end and an outer end, a sound producing diaphragm supported upon said assembly inner end, diaphragm vibrating means supported on said assembly inner end operatively connected to said diaphragm, control means controlling operation of said diahragm vibrating means mounted upon said diaphragm mount assembly, a flange defined on said diaphragm mount assembly outer end radially disposed to said assembly axis and extending outwardly with respect to said axis, said flange overlying said cavity opening at the intersection thereof with said housing exterior surface and in alignment with said cavity sidewall, means affixing said flange to said housing at said cavity opening, air passage means defined between said diaphragm mount assembly and cavity sidewall communicating with said opening and said projector wall, port means defined in said flange in alignment with said air passage means, said diaphragm being disposed in opposed spaced relation to said inner projector wall whereby sound vibrations produced by said diaphragm reflect from said projector wall through said air passage means and port means.